DVM 4 Specific

Question 1

9 week old Male Labrador

Hx: Vomiting and anorexia for 2 days

HR 144 RR 36 Temp 39.7C NAD on abdo palpation

* Why decreased serosal detail?

* The gas within the GIT– which parts contain gas? Are the gas filled portions of the GIT over distended?

* The fluid filled portions– which parts contain fluid? Are they over distended?

* Which other organs can you ID? Are these within normal limits?

* What are your recommendations for further investigation and treatment of Baughie?

Answer 1

Should not exceed 1.6 times the height of the centre of the body of L5 at its narrowest point.

SI/L5 ratio of 1.7 for diagnosis of intestinal obstruction (sens and spec only 66%)

Question 2

Layla 4 yo FS JRT

Vomiting and diarrhoea for 3 days

HR 120 MM pink to very pink CRT 1 sec, tacky

Pulses normal and synchcronous, auscultation

What are the types of ileus?- Which type is present in Layla?

How might you further investigate her diarrhoea and vomiting?

Answer 2

Question 3

Oscar 12 yo MN DLH

Hx: Vocalised and collapsed at home

CE: Systolic heart murmur, increased RR. Pale gums, tense abdomen with mass lesion palpable cranially.

Large irregularly margined mass within the cranioventral abdomen– which is the most likely organ of origin for this mass?

The mineralised opacity caudal to this mass- what is it called?

Answer 3

2-3 x the length of L2 for cats.

2.5-3.5 the length of L2 for dogs.

Hepatocellular Carcinoma

Question 4

Pip

1 yo MN Ragdoll

Trodden by a horse

HR 138 RR 32 MM pale, lethargic, distended painful abdomen

DDX for decreased intraserosal detail?

What is most likely?

What structures can you see?

Are there any MSK abn?

What procedure has been performed? Describe how you would perform this study.

Can you namet he phases of the excretory urogram?

Is there a rupture of the urinary tract? What is the most likely cause of Pips loss of serosal detail?

Answer 4

Excretory urogram is used to visualize the kidneys and ureters while the other contrast studies are used to visualise the lower urinary tract.

AKA IV Pyelogram. An iodinated contrast agent such as iohexol is injected IV. Contrast agent is rapidly concentrated and excreted by the kidneys.

Nephrogram phase- the renal cortex and medulla opacity– rate of renal opacification and wash out of the contrast agent provides a rough indication of the filtraion ability of the kidneys.

The contrast agent is excreted by the nephrons and accumulates within the renal pelvis- the pyelogram phase. The size and shape of the renal
pelvis can be assessed

Cystogram- Almost immediately, the contrast agent will pass down the ureters, and into the
urinary bladder, producing a ‘cystogram’.

Question 5

1 yo MN Burmese

5 week history of weight loss and reduced appetite

CE: Abdo palpation: pain on palpation with thickened intestinal loops/poss descending colon palpable. Estimate poss < 5% dehydrated.

DDX decreased intraserosal detail? Most likely?

Rule for assessing gastric distension?

Oval, comma shaped and C shapred SI throughout the mid abdomen? What is the rule for SI overdistension in the cat?

The distended loop of intestine containing fragmented gas opacities within the cranioventral abdomen on the lateral projection within the right cranial abdomen on the VD projection– do think this is SI or LI?

Answer 5

Stomach– no greater than 3 ICS– fundus typically 2 x wide as pylorus

Question 6

11 yo FS Maltese Terrier

Not quite right for a couple days now, vomiting

HR RR WNL- pendulous abdomen, not painful on palpation. V+ and diarrhoea

DDX intraabdominal decreased serosal detail? Most likely?

Hepatomegaly- what are the rules for assessing liver ? DDX?

Gas distended SI…

Fragmented mineral opacity in the descending colon….

Answer 6

Question 7

8 yo F GSD

Vomiting and inappetance

INcreased HR and RR, temp 40.5C, tense abdomen on palpation

Large fluid filled tubular structures within the mid to caudal ventral abdomen? What do you think this is most likely to be?

What is the circular soft tissue opacity seen on VD within the left abdomen at the level of the 5th vertebra?

Answer 7

Question 8

8 yo M Staffy

Previous history of two laparotomies- Owners concerned re: another FB

HR 130 RR 38.6C

No pain on abdo palp

Answer 8

Question 9

12 yo MN Labradoodle

Acute v+, lethargy, and profound weakness, but concurrent history of chronic vomiting and weight loss

HR 160 with injected MM

panting

Relaxed abdomen– firm area cranio ventrally– mass?? Cannot rule out tail of spleen

Gas filled stomach– rule for distension?

Over distended SI– what is the rule to assess for presence of mechanical SI obstruction?

The over distended SI loop within the mid ventral abdomen containing multiple fragmented gas opacities… what do you think this is most likely to be?

Ventral spondylosis L2-3

What is your plan for Austen

Answer 9

Question 10

10 yo MN Himalayan Cat

hx: Constipation

CE: 240 HR, RR 30, Pale MM, tense abdo, bladder distended, difficulty passing catheter

Why do they look different?

What procedure?

What contrast agent?

What is the dose rate?

Can you ID the reason he has having trouble urinating?

Answer 10

Question 11

Janis 13 yo Bull Terrier

Presenting: Dull, showing signs of depression, tachycardic, very tense on abdo palpation

The decreased intra-abdominal serosal detail centrally- what are the differential diagnoses for decreased intra-abdominal serosal detail? What is most likely?

Abnormal fragmented gas opacities in the ventral abdo- What are the DDX for pneumoperitoneum? Do you think it is free gas within the abdomen or within an organ? If you think it is arising from an organ, which do you think is the most likely organ of origin for these fragmented gas opacities?

Answer 11

Question 12

5 yo M JRT “Spike”

Stranguria since last night, vomited twice

CE: Panting and agitated, tense on abdominal palpation, no other abnormalities on abdo palp

Answer 12

Question 13

Vanessa 4 yr old F Doberman

Whelped 6 live and 2 dead puppies 24 hours prior to presentation. Noted to be straining again on morning of presentation. Bitch quiet and has reduced appetite.

HR 124 RR 36 MM tacky T 39.4C

Answer 13

Question 14

14 yo M King Charles Spaniel

Presenting complaint: Purulent saliva from mouth, malodorous breath. Enlarged submandibular LNs. Grade V systolic heart murmur, normal resp rate/ sounds. Thoracic radiographs taken prior to GA for dental.

CE: 160 HR, RR 40, Temp 38.5C. Grade V Systolic heart murmur.

Rules for assessing cardiac silhouette?

VD/DV RG do the caudal lobar veins lie medial or lateral the arteries?

Is this dog in Left sided CHF?

Are you happy to go ahead with the dental?

Answer 14

Question 15

Will you see anaemia with haemorrhage? With a severe coagulopathy, what are possible ddx?

Answer 15

* Yes + possible hypovolaemic shock

* Anticoagulant rodenticide toxicity, hepatic failure, DIC, malabsorptive diseases

Question 16

When might you see mild thrombocytopenia?

Answer 16

Secondary from blood loss/ increased utilisation, DIC

Question 17

What is a heart murmur? Why would you see a heart murmur with anemia? What else could cause a heart murmur?

Answer 17

* Heart sounds produced when blood flows across one of the heart valves that is loud enough to be heard with a stethoscope– vast majority are due to turbulent blood flow brought on by high velocity blood flow

* the body has a lower than normal number of RBCs therefore the blood is thinner and flows faster than normal

* Structural abnormality (e.g. valve leaflet), fever, hyperthyroidism

Question 18

In a dog with anticoagulant rodenticide toxicity, what kind of blood transfusion product would be ideal?

Answer 18

Fresh whole blood for the red cells, clotting factors, proteins, and platelets (lack of vitamin K reductase does not allow the activation of vitamin K and therefore lack of clotting— so fresh whole blood with stop bleeding by providing clotting factors that have been lost)

** Max is also hypovolemic and hypoxic shock from severe anemia– so supplementation of red cells is essential

Question 19

What are possible complications from a transfusion?

Answer 19

* Acute immunological transfusion reaction- acute hemolytic reaction (type II hypersensitivity reaction), febrile non hemolytic reaction, non-hemolytic immunological reaction (type I hypersensitivity)

* delayed immunological transfusion reaction- delayed hemolytic reaction, post transfusion purpura (internal bleeding)

* acute non immunological tranfusion reactions- bacterial contamination of transfused bloods, hemolysis from damaged RBC transfusion, hyperkalaemia/hypocalcemia/hypomagnesemia after massive transfusions, hypothermia, circulatory overload

Question 20

What are some things you can do to prevent transfusion reactions?

Answer 20

* blood typing (especially cats), cross matching major and minor (especially if second transfusion), test infusion 0.25 m/kg/h over the first 5-10 minutes, use of an in line blood filter, monitor patient parameters every 15-30 minutes during transfusion for acute reactions (demeanor, temperature, pulse rate and quality, BP, RR and character, MM colour, plasma and urine colour), ensure transfusion complete within 4-6 hours to preven bacterial growth, proper collection and storage of blood, appropriate blood donor screening

Question 21

Dog with anticoagulant rodenticide poisoning, what other treatments over than an infusion?

Answer 21

* Vitamin K1 supplementation

* strict cage rest to prevent further hemorrhage

* oxygen supplementation

* Intravenous fluids

Question 22

What are X-rays?

Answer 22

A form of electromagnetic radiation

EM radiations of frequencies higher than UV light have enough energy to remove an outer-shell electron from an atom and are therefore called ionising radiation (X-rays, gamma rays, and cosmic rays are ionising radiation). When ionising radiation interacts with atoms it causes the ejection of an electron and creates an ion pair which has the potential to damage cells.

** They can produce damage to molecules and induce temporary or permanent cell damage, causing problems such as mutations or cancer

Question 25

What are some unusual properties of ionising radiation?

Answer 25

* You cannot see, smell, touch or taste it

* Penetrates all matter

* We do not develop tolerance or immunity to radiation

* There is little difference between how individuals react to a given dose

* Dose is cumulative

* Delayed effects: May take years to see the effects

Question 26

What does it mean that effects of radiation are stochastic or deterministic?

Answer 26

* Stochastic- increased risk with increased dose– the dose of radiation you receive, a higher dose of radiation will increase the probability of a stochastic effect e.g. a genetic mutation leading to cancer– higher radiation dose or exposure will increase the chance of cancer developing (this is the one that is important in vet med)

** no threshold below which the risk of the effect will cease & effects are cumulative over a lifetime

* Deterministic- inevitable at high doses– in contrast with stochastic effects, the severity of the effect, not the probability, increases with increasing dose. Exposure below a certain threshold will not result in the effect (THERE IS A THRESHOLD). e.g. radiation induced skin burns, uncommon however in medicine

Question 27

What is the direct effect of ionising radiation? Indirect effect?

Answer 27

* direct effects may damage DNA, protein or other macromolecules

* Indirect effects create free radicles within cytoplasm and these free radical damage macromolecules

** Cell may either repair itself or if DNA damage has occurred a mutation may result, causing cell death, cancer, or birth defects

Question 28

In Victoria, the use of radiation comes under what department? And which Act? What does it state?

Answer 28

* Department of Health which administers The Radiation Act 2005– species that business must have a management licence to possess a radiation source and conduct a radiation practice & individuals must have a use licence

Question 29

What is ARPANSA?

Answer 29

* A national governing body – Australian Radiation Protection and Nuclear Safety Agency– responsibility for protecting the health and safety of the people and environment from the harmful effects of ionising radiation. They publish a series of codes and standards then implement in the form of legislation.

RPS 17: Radiation Protection in Veterinary Medicine (2009)

** Also provide “Personal Radiation Monitoring Service”– monitors and records occupational exposure to radiation

Question 30

What are the three basic methods of monitoring for radiation exposure?

Answer 30

* Thermoluminescent Dosemeter (TLD)- electrons int he crystal structure of the TLD card are excited to high energy levels as a result of irradiation and are trapped in the crystal structure. By heating the material, electrons return to their ground state and light is emitted. The amount of ligh is proportional to the radiation dose that the TLD material has received. Filters are used to allow only certain radiation to pass.

* Film badges- degree of darkening can be measured and will indicate the absorbed dose. But dose to film does not equal dose to tissue.

* pocket dosimeters– different to TLDs and film badges… pocket dosimeters can be read instantaneously– useful when high exposures are expected.

Question 31

What tissues are more susceptible to radiation?

Answer 31

Rapidly dividing tissue

Question 32

What is the recommended effective dose limit for occupational exposure? In a single year? What is the avg annual dose for veterinarians?

Answer 32

20 mSv per year, averaged over consecutive years
* 50 mSv in a single year

** Avg annual dose for veterinarians is around 16 microSv = 0.016 mSv

Question 33

What is the ALARA principle?

Answer 33

* As Low As Reasonably Achievable

** Is the radiograph necessary for the patient and management of the case? Would ultrasound or a blood test answer the clinical question?

* Minimize retaking radiographs, minimize manual restraint, under no circumstances should any part of your body be within the primary x-ray beam

Question 34

What are the three types of radiation encountered in medical practice?

Answer 34

* Useful beam

* Leakage radiation

* Scatter radiation

Question 35

How can radiation exposure be minimised ?

Answer 35

Modifying

1. Time (take good radiographs the first time around)
2. Distance from the radiation source– the energy of the scatter radiation will decrease as distance from the radiation source increases, according to the inverse square law… e.g. so by doubling the distance from the radiation source, you will reduce your radiation exposure by a factor of 4. (avoid manual restraint, use ancillary positioning devices such as sand bags, stand well back)
3. Shielding- concrete walls, PPE

Question 36

How thick should lead PPE be?

Answer 36

Lead equivalent of 0.25 mm will shield scatter radiation with energy of up to 100 keV (electron volt)

Question 37

How are x-rays generated? What elements are necessary for x- ray production?

Answer 37

* Generated in the x-ray tube by firing a high energy electron beam at a tungsten target

1. A source of electrons (cathode)
2. An obstacle- free path for the passage of high speed electrons
3. A target (the anode) in which the electrons can interact, releasing energy in the form of x-rays
4. a method of accelerating the electrons- electrical potential difference applied between the cathode and anode

Question 38

What should the local radiation management plan follow?

Answer 38

ARPANSA RPS 17 + ALARA by observing time distance and shielding principles

Question 40

What is the cathode? What is it made of?

Answer 40

* cathode acts as a source of electrons

* it is of a tungsten coiled filament mounted within a molybdenum focusing cup. Tungsten has a high melting point and a high atomic number. When a current is run through the cathode filament, it heats up and releases electrons.

Question 41

What is the anode? What is it made of?

Answer 41

* when an electrical potential difference is applied across the x-ray tube, the anode has a positive charge relative to the cathode and attracts the electrons

* When electrons collide with the anode, 99% of the kinetic electron energy is converted to heat and only 1% gets converted into x-rays

Because of the heat produced anodes have a tungsten target which is resistant to heat. This is mounted on a copper base which helps conduct heat away from the target. (Either rotating– more powerful x-ray machines– or stationary– dental and portable– copper base)

Question 42

What is the glass envelope?

Answer 42

* Contains the cathode and anode within the vacuum. The x-ray tube has a small exit window through which the x-ray photons escape. The tube is surrounded by oil which helps dissipate the heat and acts as an electrical insulator.

Question 43

What is meant by quantity in regards to properties of the x-ray beam? Quality? Intensity?

Answer 43

Quantity= the number of x-ray photons produced

Quality- the energy of the x-ray photons, hence their penetrating power

Intensity- the amount of x radiation per unit area. The intensity is determined both by the number of photons and the energy of each photon

Question 44

What does the quantity of electrons produced at the cathod filament dependent on?

Answer 44

The electrical current of the cathode circuit. This is an adjustable parameter that the x-ray machine operate can control, known as the Milliamperage (mA) setting. Increasing mA increases the number of electrons within the electron cloud

Question 45

What does increasing mA do?

Answer 45

Increasing milliamperage (mA) increases the number of electrons within the electron cloud

Question 46

What does the higher the kV mean? What is kVp?

Answer 46

* In order to accelerate the electron cloud toward the anode and produce x-rays, a potential difference or kilovoltage (kV) is applied between the anode and the cathode. The highter the kV, the greater the acceleration and thus the greater the energy of the electrons– the greater the energy of electrons– the greater the resultant x-rays which EQUALS HIGHER QUALITY X-rays

** kVp- kilovoltage peak- the maximum voltage available at the kV setting and is an adjustable paramter that the x-ray machine operator can control

Question 47

What is the meant by the exposure time?

Answer 47

* The potential difference between the anode and cathode is only applied for a very short period of time (milliseconds)– the exposure time is an adjustable parameter that the x-ray operator can control. A long exposure time allows may electrons to impact with the anode, while a short exposure time allows fewer electrons to impact with the anode

Question 48

What is the quantity of x-rays produced a function of? What determines the quality of x-rays produced?

Answer 48

both the mA setting and the time setting (s)

** mA determines the number of electrons produced, while time determines the number of electrons that hit the anode

** some x-ray machines allow the operator to select the mA and s independently

** kVp setting determines the energy of the electrons and therefore the energy of the resultant x-rays and thus the quality or penetrating power of the x-rays

Question 49

How does the radiographer ensure the x-ray beam has the appropriate intensity?

Answer 49

Intensity = quality and quantity of x-ray photons

* this is so that enough x-ray photons penetrate the patient and interact with the x-ray detector to form the image

* The x-ray operator achieves this by manipulating the kVp, mA, and second settings on the machine to be appropriate for the anatomic area that is being radiographed

Question 50

What is the focal spot? What does the size focal spot influence?

Answer 50

The area of the target with which the electrons collide… the size of the focal spot influences the detail (edge definition) of the image and also affects the heat loading capacity of the machine.

e.g. a stationary anode is limited to having a larger focal spot in order to accomodate higher temperatures. The focal spot of a rotating anode can be smaller due to the larger surface area over which electrons impact the target and superior ability of a rotating anode to dissipate heat.

Common focal spot sizes in veterinary medicine are 1-2 mm^2

Question 51

What is the collimator?

Answer 51

The device to limit the size and shape of the primary x-ray beam

* To minimize scattered radiation, the primary beam should be confined to a size and shape that will just cover the region of diagnostic interest

Question 52

What are the benefits to using the collimator to limit the x-ray beam to the area of interest?

Answer 52

Less scatter radiation is produced which improves image contrast and image quality and radiation safety…

Question 53

What is full wave rectification?

Answer 53

* Converting the AC into a direct current (DC) without losing any electricity– full wave rectification creates a nearly constant electrical potential across the x-ray tube as both halves of the alternative voltage are used to produce x-rays

* A consideratlbe portion of the exposure time is still lost however while the voltage is in the valley between the two pulses

Question 54

What is a three phase generator?

Answer 54

Present in most modern machines- produce an almost constant electrical potential difference between the anode and the cathode, which results in:

1. More power available to the x-ray tube per unit time and therefore for shorter exposure
2. Intensity of the x radiation generated is higher
3. Radiation quality is greater because it contains less low energy x-rays
4. Tube utilisation is more efficient because the target is not subjected to bombardment of low energy electrons, which only create heat

** main disadvantage is the increased cost of the machine relative to more simply rectification machines

Question 55

What are the three main parts of the x-ray machine generator?

Answer 55

* The control panel- allows the operator to select appropriate setting for the voltage (kVp), tube current (mA), and the time of exposure (sec)

* The transformer assemby- step up or step down transformers to increase or decrease the voltage as required (which is needed to boil electrons from the filament and to accelerate these electrons from the cathode to the anode)

* The rectification circuit- incoming mains electricity is alternating current (AC), when x-ray exposure is made and a potential difference is applied across the x-ray tube, direct current (DC) is required. Most efficient systems produce constant positive lectrical potential, cheaper units the DC is more variable and only reaches peak voltage (kVp) for a small proportion of the time

Question 56

What are the two stages that accomplish the exposure?

Answer 56

* Preparation- press and hold the button on the hand piece half way down; the cathode is heated by the cathode current and the anode starts rotating

* Exposure- when the system is ready, the operator fully depresses the button; this causes the potential voltage to occur for the set exposure time

Question 59

What is the tube rating? What is it based on?

Answer 59

Each x-ray machine has a tube rating expressed in kilowatts– the tube rating dictates themaximum combinations of kVp, mA and time that can be safely used without over-loading the tube

Based on:

1. Focal spot size
2. Target angle
3. Anode speed
4. Electrical current

Question 60

How is a radiographic image formed? What is attenuation?

Answer 60

Differences in attenuation between different components of the object to be radiographed. Attenuation is the proportion of x-rays that are stopped/ absorbed by a given thickness of matter

Question 61

What 3 things happen when x-ray hits matter? What determines which one predominates?

Answer 61

1. Transmission- the x-ray photon passes straight through
2. Photoelectric effect- x-ray photons can be absorbed
3. Compton effect- x-ray photons can be scattered

** Which one of these interactions predominates is determined by:

• energy of the x-ray beam (kVp)
• atomic number of the absorber. Remember more interactions occur with matter that has a high atomic number
• thickness and density of the part being radiographed. It makes sense that thicker or denser objects will stop more x-rays.

Question 62

What is the photoelectric effect?

Answer 62

PE results in complete absorption of an x-ray photn by an atom and the ejection of an orbital electron, which produces a positive ion. Largely responsible for radiographic contrast. The main way x-rays are attenuated at 40-120 kV. The primary interaction between x-rays and bone.

** Probability of the PE depends on:

1. Energy of the x-ray photon (must be above threshold kV)
2. Atomic number of the absorber (elements with a higher atomic number are more likely to have PE absorption)

Question 63

When is PE more likely to occur?

Answer 63

In low energy x-rays (50 to 70 kVp)

* high Z material (more in iodine, barium and lead than in oxygen, carbon or hydrogen)

** PE explains why better contrast is achieved with low kVp and why iodine and barium (used in radiographic contrast studies) stop more x-rays than organic matter

** soft tissue is made up of hydrogen, carbon, nitrogen, and oxygen– avg atomic number of 7.. vs. bone which is mostly calcium (atomic number 20)

Question 64

How do you increase subject contrast?

Answer 64

Decrease the kVp setting

Question 65

Why is PPE made from lead?

Answer 65

Atomic number is Z82– materials made from elements with a high atomic number are good absorbers of x-rays

Question 66

What is screen speed?

Answer 66

Part of a cassette. An important characteristic of intensifying screens. Faster screens requires less radiation (lower mAs, usually achieved with shorter exposure time)– at the expense of detail however.

Question 67

What is the compton effect? Why is it not useful in diagnostic radiology? What influences the likelihood of the compton effect?

Answer 67

Responsible for almost all the scatter radiation produced in diagnostic radiology

No useful function in diagnostic radiation because

1. Scattered radiation poses a safety threat
2. Decreases contrast of the radiographic images (e.g. the difference between black and white on the radiograph is less obvious)

** Likelihood of the compton effect

1. Very dense absorbers are more likely to produce compton scatter
2. large volumes of irradiated tissue are more likely to produce compton scatter– thick body aprts e.g. fat dog abdomen, horse back or shoulder; or poorly collimated image will produce more scatter
3. High kVp settings thuse higher energy x-ray photons are more likely to produce compton scatter

Question 68

How do you absorb scatter radiation before it hits the detector?

Answer 68

Use a grid

They should always be used when the patient thickness is greater than 10 cm because more scatter is produced in thicker body parts

Placed between the patient and the detector- so under the patient or under the table between the patient and the cassette

Question 69

What is the relationship between optical density of a radiograph to the exposure needed to produce that density?

Answer 69

Sigmoidal

* Ideally, most of the radiographic image should be exposed in the linear portion of the curve. If the film is exposed at the shoulder or toe of the sigmoidal curve, the image will appear overexposed (too dark) or under exposed (too light) respectively

Question 70

How does a film screen x-ray work? What is the most commonly used x-ray films?

Answer 70

* x-ray film consists of a polyester base coated on both sides with a gelatin emulsion containing silver halide crystals. When visible light or x-rays interact with silver halide crystals- an invisible image is formed then processed to be made visible– by exposing the silver halide to an x-ray photon or light photon which activates the crystals which precipitate silver… which aggregates producing darkenened areas

** Most commonly used x-ray films are double emulsion- having emulsion on both sides of the base (single emulsion can be used with pocket pets)

Question 71

What are cassettes?

Answer 71

Cassettes are used in traditional film-screen and computed radiology (can be reusable)

* rigid lightproof containers that hold both the intensifying screens and the radiographic film. Double emulsion film is used in cassettes with two screenes which therefore results in two images on either side of the film

Question 73

What is an intensifying screen? Why must the x-ray film match the intensifying screens of a cassette?

Answer 73

* Intensifying screens in a cassette convert x-ray photon energy into light photons, which expose the x-ray film. The use of film with intensifying screens (film-screen) is a more efficient detection system than x-ray film alone and allows a reduction in radiation exposure up to 100 times.

* X-ray films are only sensitive to one colour of light and different screen types give off different colours

Question 74

What is optical density ? What is it primarily controlled by?

Answer 74

Measure of the blackness of film– primarily controlled by mAs

Question 76

What is film speed?

Answer 76

Term used to describe how sensitive the film is to x-ray or light photons. Film that has a high speed rating is very sensitive to photons, an adequate optical density can be achieved with lower radiation exposure. The trade off for fast fil is that it has slightly lower detail/ spatial resolution compared to slower film.

Question 77

What is film latitude? What is film latitude’s relationship to film contrast?

Answer 77

Exposure range over which acceptable optical densities are produced. Film with a wide latitude will accept a significant variation in exposure factors or processing without exhibiting any great chance in optical film density. Most x-ray film has WIDE LATITUDE making it relatively easy to avoid under or over exposure… narrow latitude film or high contrast film is less forgiving with exposure factors– FILM LATITUDE VARIES INVERSELY with FILM CONTRAST

Question 78

CR advantages and disadvantages?

Answer 78

Question 79

What speed film would you want to use for cat’s manus?

Answer 79

Slow speed 100 to 200- higher in detail, small body part, very little movement so longer exposure times okay to use

Question 80

Advantages and Disadvantages of DDR

Answer 80

Question 81

What speed film would you use for a fat dog’s abomen?

Answer 81

Fast speed- 400 to 600 speed

Question 82

What film speed would you want for a horse’s carpus?

Answer 82

400 speed- fast system. Move a lot so short exposure time

Question 83

What are the steps in film processing?

Answer 83

1. The Developer- chemical solution that converts the latent image on the film to a visible image by reducing exposed silver halide crystals to black metallic silver. ** Time and temperature dependent (chemical reaction occurs at a greater rate at higher temperatures)– usually at 20C about 3 minutes to develop
2. The rings- x-ray film retains developer in the gelatin and if this were transferred to a fixer the alkaline developer would neutralize the acid fixer– so rinsing stops the developing processes and prevents carry over the fixer
3. The Fixer- removes unexposed silver halide crystals. Fixation also hardens the gelatin coating so that it can be dried without damaging the film surface. Fixed fro twice the development time to ensure maximum hardening of the emulsion. An incompletely fixed film takes on a milky or cloudy appearance.
4. Wash Bath- removes the remaining silver complexes and excess fixer. (20-30 minutes)
5. Dry the film. Hanging.

Question 84

What are the limitations to traditional film- screen?

Answer 84

Image can have good contrast or good latitude but not both

* And once the film has been exposed to the x-rays, the contrast and latitude can’t be adjusted

Question 85

What are the three steps of Computed Radiography?

Answer 85

1. Image acquisition- x-ray photons strike a reusable storage phosphor imaging plate (IP)– placed in a plate reader where it is scanned by a laster beam which releases the stored latent image as visible light. Then the IP plate is erased for reuse by scanning the plate with an intense white light
2. Image processing- using algorithms the computer evaluates and manipulates the digital data
3. Image display- the user can then apply post processing techniques such as edge enhancement, magnification, adjustment of contrast range and dynamic range

Question 87

How does direct digital radiography work?

Answer 87

* Direct systems use an electronic detector made of amorphous silicon or selenium or a charged couple device to capture the image. The detector is attached to the computer system via a cable. The signal is transmitted to the computer and reassembled into a digital image.

Question 89

What is the major advantage of digital imagine?

Answer 89

Due to the wider latitude, the number of retakes due to poor exposure are reduced

BUT although digital image contrast can be manipulated by viewing software, subject contrast is still influenced by collimation, scatter and kVp settings

Question 90

What are the six basic steps in making a technique chart?

Answer 90

Question 91

What is quantum mottle?

Answer 91

An underexposed digital image will have a grainy appearance

Quantum mottle is caused by the discrete nature of an x-ray photon; underexposure results in an insufficient number of x-ray photons reaching the detector to fully form the image

*** think of black paint spots outlining something

Question 92

What does radiographic contrast depend on? When is high contrast preferred? When is low contrast preferred?

Answer 92

Radiographic contrast depends on:

1. Subject contrast- due to attenuation of the x-ray beam in different tissues; low kVp will produce high subject contrast as long as the kVp is high enough to penetrate the tissue (higher kVp = more compton scattering)
2. Film contrast- homogeneity in size of silver halide crystals within the film emulsion, over or under exposure– technical factors, over or under deveopment will push film contrast to the toe or shoulderof the characteristic curve and produce low contrast image
3. Fog and Scatter- inadvertent exposure of the x-ray film to light

High contrast is preferred for bone images; low contrast is preferred for chest and abdominal images

Question 93

How does spatial resolution of digital systems compare to film-screen systems? Does this matter?

Answer 93

* Spatial resolution of digital systems is not as good as film-screen systems, but it is not a clinical limitation

Question 94

Effect of kVp, mA and exposure time on the radiographic optical density and contrast

Answer 94

Question 95

What are the four steps to processing the digital image that occur automatically?

Answer 95

1. Creation of a histogram- maps optical density vs. frequency which allows mathematical manipulation of the raw data- histogram is compared to an expected histogram for the anatomic area selected to be radiographed
2. Data adjusted for under or over exposure- histogram shifts left or right to compensate
3. Enhancement of image contrast, using a look up table
4. Edge enhancement or smoothing- complex mathematical function is applied to the raw data to allow processing in the spatial frequency domain– boundaries such as bone margins can be smoothed or enhanced

Question 96

What is PACS?

Answer 96

Archiving and distribution of digital images

Question 97

What are the features of radiographic image quality?

Answer 97

* Optical density, radiographic contrast (subject contrast, film contrast, fog and scatter, digital image contrast), detail (spatial resolution, edge definition), technical faults

Question 98

How can optical density be manipulated?

Answer 98

By adjusting mAs (mA or seconds) setting

Question 99

How does a film with high optical density appear? Why would this occur? What should you do?

Answer 99

Too dark over-all due to overexposed (too much radiation reached the film– likely because mAs setting was too high) or over-developed.

** may also occur if film-focal distance is too short

** If too dark then reduce mAs +/- increase the film focal distance

Question 100

Why does under exposure occur? What should you do?

Answer 100

* check kVp settings– have to be high enough to produce x-rays that will penetrate the patient

* most common cause of under- exposure is too low mAs setting… therefore increase the mAs and maybe increase the kVp

Question 101

What is a technique chart?

Answer 101

Helps us determine the best x-ray machine settings (kVp, mA, seconds)

* technique charts are specific to the x-ray machine, film-screen speed, film to focal distance, whether a grid is used

** measure the thickness of the area you intend to radiograph and read off the technique chart what the ideal kVp and mAs setting should be

Question 105

What are the four factors that determine the degree of attenuation of an x-ray beam as it passes through matter?

Answer 105

1. Thickness of the absorber
2. The density
3. Atomic number
4. Energy of the radiation

Question 107

How can you reduce the production of scatter? How can you reduce the impact scatter has on the xray image?

Answer 107

* Reduce production of scatter by

1. Selecting lower kVP (still has to be high enugh to penetrate the patient)
2. restricting the collimator field to only the area of interest

* Reduce impact of scatter on the x-ray image

• using a grid when you radiograph body parts thicker than 10 cm
• having a small air gap between the patient and the cassette
  3. Reduce scatter radiation dose to the operator
• PPE
• distance

Question 108

What is the biggest contributor to contrast of digital images?

Answer 108

The image processing algorithm and windowing of the image by viewing software (still impacted by subject contrast and scatter radiation)

Question 109

What are the five basic radiographic opacities?

Answer 109

Question 110

What are the two main components of image detail?

Answer 110

Spatial resolution and edge definition

Question 111

What is spatial resolution? How does film screen compare to digital? How is it determined?

Answer 111

* determined by the x-ray detector– ability to distinguish between two adjacent contrasting objects

** gilm- screen has better spatial resolution than digital… but advantages of edge-enhancement, superior latitude and ability to zoom images outweighs the disadvantage of lower spatial resolution

** Spatial resolution of film-screen is determined by the size of the halide crystals of the film emulsion and the size of the phosphor crystals of the intensifying screen

** Spatial resolution of digital radiography is determined by the size of the detector elements and size of the pixel matrix used to store the image

Question 112

What is penumbra? What determines?

Answer 112

Edge definition

geometric factors that determine:

1. Focal spot size (small focal spot produces a shart image, think of hand and iphone)
2. Focal spot to film distance (as large as possible is important to improve image sharpness and reduce magnification)
3. Object to film distance (close to the film as possible to improve image sharpness and reduce magnification)

Question 113

Main causes of a blurry image?How can this be minimized?

Answer 113

Motion of the patient or cassette

* Minimized by shortening exposure time, sedation and anaesthesia

** Cassette motion a problem in equine radiography where cassettes may be positioned by a cassette holder

* blurry images can also be caused by geometric factors taht increase the penumbra

Question 114

What is B-mode ultrasound imaging?

Answer 114

Question 115

What is M-mode ultrasound?

Answer 115

Question 116

What is Colour Doppler?

Answer 116

Question 117

What is spectral doppler?

Answer 117

Question 118

What is distortion resulting from?

Answer 118

Unequal magnification of different parts of the same object

Question 119

What is forshortening?

Answer 119

* object being radiographed must also be parallel to the film

Question 120

What three things might happen when ultrasound pulses interact with the patient?

Answer 120

1. Transmission into deeper tissues
2. Refraction (bending) of sound as it passes from a tissue of one density to a tissue of a different density
3. Attenuation of sound, which is a reduction in amplitude or intensity of the pressure wave

Question 121

What is parallax error?

Answer 121

Since the x-ray beam is divergent the periphery of radiographic images have different projections– e.g. spine radiographs

Question 122

What is a B-mode ultrasound image composed of? What does the brightness of each x correspond to?

Answer 122

Question 123

What is acoustic impedance?

Answer 123

* Sound reflection or transmission characteristics of a tissue, largely dependent on the density of the tissue and speed of sound within the tissue. Because we assume constant speed of sound in soft tissue, density is the most important component in this equation

** It is not exact value of acoustic impedence that matters but the difference in acoustic impedence between two tissues

** At boundaries between soft tissue and boen or soft tissue and air there are large differences in acoustic impedance resulting in little sound transmission and the image is displayed as a shadow– THIS IS WHY WE CLIP ANIMALS FUR, clean the skin and apply coupling gel– this removes air between the skin and transducer

Question 124

WHat is the preferred imaging modality to assess bone or lung?

Answer 124

Question 125

What does the ultrasound transducer do?

Answer 125

* converts electrical energy to acoustic energy and acoustic energy to electrical signals

* consist of piezoelectric crystals aligned within the footprint of the transducer and when a voltage is applied the crytal vibrates and produces a sound– each one has a unique frequency at which is vibrates and will produce sound of an inherent frequency. The tranducer transmits sound pulses for 1% of the time and listens for returning echoes 99% of the time.

** The operator can select the main frequency band that is used for imaging, selecting higher frequencies for imaging superficial structures and lower frequencies for deeper

Question 126

Answer 126

Question 127

What is the phased array?

Answer 127

Question 128

What is an artefact?

Answer 128

* Structure or feature not normally present in an image, but visible as a result of an external agent or action– fake out

e. g. film screen dark marks caused by pressure on the film or white marks– dust or hair int eh cassette which prevents light from the intensifying screen from reaching the film
e. g. grid cut off appears as light areas caused by misalignment or inappropriate placement of a focussed grid
e. g. milk/ opaque image- typically a problem with manual processing- incomplete fixation leaving behind silver halide crystals OR brown image– incomplete washing leaving fixer behind which oxidises over time OR linear roller marks with automatic processors with dirty rollers
e. g. digital artefacts- grainy image = underexposure; double image- double exposure with both images displayed due to wide latitude radiography; moire artefact- bands or lines from ; white lines on a CR image- dirty plate readers; misapplication of the algorithm- poor collimation and beam centering can result in mis-application of the algorithm and poor image contrast resolution; uberschwinger- excessive edge enhancement appears as a thin black rim around high denisty object such as bone margins or metal implants and may mimic bone lysis

Question 129

What is axial resolution?

Answer 129

Dependent on the spatial pulse length

Question 130

What is lateral resolution?

Answer 130

Question 131

How do contrast agents work? What are the two main categories?

Answer 131

Work by having different physical density and atomic number hence different radiogrpahic density than normal patient tissue.

* Positive and negative contrast agents

Question 132

how do negative contrast agents appear? Examples of agents? Examples of studies? Risk?

Answer 132

* Negative contrast agents are gaseous and do not effectively absorb x-rays so appear radiolucent (dark)

** room air, carbon dioxide, nitrous oxide

** used to inflate organs e.g. GIT- pneumogastrogram or pneumocolon, or urinary tract- pneumocystogram

** Risk of fatal air embolism if any gas leaks into the vascular space e.g. damaged mucosa from necrotising haemorrhageic cystitis– to minimize risk of death from air embolism when performing pneumocystogram place patient in left lateral recumbency and use CO2 or NO which are more soluble than room air (would be reabsorbed in the right ventricle otherwise could become trapped in pulmonary artery or travel and occlude pulmonary circulation)

Question 133

What are positive contrast agents? Examples of agents? Which agents used where?

Answer 133

* Positive contrast agents have a higher atomic number than soft tissue, thus are an efficient absorber of x-rays and appear more radiopaque

* iodine- Z= 53; barium Z= 56

** Barium used in the GIT– irritant so not IV– excreted by the GIT

** Iodinated contrast agents are ionic or non-ionic. Ionic agents are markedly hyperosmolar relative to blood so are associated with adverse reactions such as hypotension, nephrotoxicity and thrombosis– excreted by the kidneys, biliary tract, GIT, saliva

** All iodinated agents can trigger allergic reactions

* Iodinated agents– angiography (IV), cytography (urinary tract), myleography (spinal cord)

** Myelography should only be performed with non-ionic!!

Question 134

What are the conventional hanging protocols?

Answer 134

* Dorsoventral OR ventrodorsal radiograph of the body- head at the top and the patient’s right on the viewers left side

* Lateral radiograph- animal standing with the head to the viewers left and dorsal (for the body) or proximal (for the limbs) to the top of the screen

* Craniocaudal or dorsopalmar/ dorsoplantar- proximal is to the top and the lateral aspect displayed to the viewers left (no matter whether you are looking at the left or right limb)

Question 136

Indications for ultrasound

Answer 136

* internal structure of organs- size, shape, margins

* dynamic evaluation of blood flow– which can provide some information on organ function e.g. echocardiography where blood flow and changes to the heart size over the cardiac cycle can be measured

* more sensitive at detecting pathology, low specificity for identifying a specific disease

* GIT e.g. heptobiliary disease, pancreatitis, vascular anamolies such as portosystemic shunts

Question 137

Patient preparation?

Answer 137

* Hair coat clipped, skin cleaned and alcohol applied to defat the skin, ultrasound gel applied to provide good acoustic coupling (transmission of sound) to reduce artefact and allow the ultrasound probe to slide over the skin

Question 138

Special considerations for echocardiography ?

Answer 138

Sedation will affect cardiac function, so preferably an unsedated animal

Question 139

Special considerations with scintigraphy?

Answer 139

Question 140

Special considerations for abdominal ultrasound? Musculoskeletal ultrasound?

Answer 140

* Abdominal- animals should be fasted

* musculoskeletal ultrasound- may benefit from using a stand off pad since structures are superficial and often hard

Question 141

What is the Hounsfield scale?

Answer 141

The operator can choose what part of the scale to assign the central colour gray

Question 144

What is an MRI sequence?

Answer 144

Question 146

Safety issues with MRI?

Answer 146

Question 148

What is duplex doppler ultrasonography?

Answer 148

Simultaenous use of real time B mode imaging and spectral doppler.

Question 149

What is sound? What is the relationship of wavelength and frequency at a given velocity? What is the range of frequencies of ultrasound? What is the assumed constant speed of sound for ultrasound and where is that number from?

Answer 149

* Sound is a pressure wave with properties of wavelength, frequency, velocity and amplitude

* For a given velocity, wavelength and frequency are inversely related e.g. high frequency = short wavelength.

* ultrasound has frequencies between 2 and 20 MHz

* Ultrasound assume constant speed of sound at 1540 m/sec (which is the average speed of sound in soft tissues)

Question 151

What does sound attenuation depend on? What kind of transducer do we use for superficial structures? Deep structures?

Answer 151

* Sound attenuation depends on the distance travelled and teh frequency of sound

* High frequency tranducer for superficial

* low frequency to image deeper structures

Question 152

What is Poiseulle’s Law? How does it relate clinically?

Answer 152

Physical law that governs the pressure drop in a gluid flowing through a long cylindical pipe. Clinically you can think about how it governs the pressure needed to push a volumetric rate of fluids e.g. in ml/hr through your tube (catheter)

** both length and radius have an effect on catheter flow but the radius effect is much greater than length. Double the length, you double the pressure it takes to get fluid through at the same rate…. Catheters have a high resistance to flow. 18 gauge are the biggest we use in peripheral veins.

Question 153

What gauge through rabbit ear veins, bird wings and tiny kittens?
What gauge through cats and very small dogs?

Large cats and medium sized dogs?

Larger sized dogs (heeler upwards)?

Answer 153

Question 160

What should you consider when selecting a transducer?

Answer 160

* consider frequency of the transducer and the footprint or shape of the field of view of the transducer

Question 163

how is the best spatial resolution achieved?

Answer 163

Imagine with a high frequency transducer and imaging within the focal zone

Question 164

When are low dynamic range setting used for? When are high dynamic range setting used for? What is true for both?

Answer 164

Low dynamic range settings are used for echocardiography

* High dynamic range for abdominal ultrasonography

* You will have the best perception of contrast resolution when imaging with a low gain setting in a darkened room

Question 165

What is nuclear scintigraphy?

Answer 165

Allows imaging of the distribution of radiopharmaceuticals within the body using a gamma camera. It allows imaging of both structure and function

Question 166

What is the most commonly used radionuclide in vet med?

Answer 166

Technetium- as it decays, the nucleus is converted to a more stable state by emitting gamma radiation which is detected by a gamma camera. It has a half life of 6 hours– long enough for most imaging procedures to take place but short enoug hthat the radioactivity of the patient rapidly decays, typically reaching background levels within 24 hours… thus minimizing radiation dosage to the patient, staff and owners

Question 167

Static vs. dynamic nuclear scintigraphy

Answer 167

* Static mode- provides anatomic information about the distribution of the radiopharmaceutical at one point in time, allowing determination of organ size, shape, position and pattern of distribution that may be specific for a disease state e.g. bone scintigraphy– shows areas of active bone turnover as seen with physes, stress fractures, infection or bone neoplasia

** dynamic mode provides functional information allowing measurement of rate of accumulation or removal or the radiopharmaceutical within an organ– example is portal scintigraphy where a series of images is acquired over a four minute period allowing mapping of the passage of pertechnetate through the portal circulation, liver and heart

Question 168

What is the most appropriate description of the radiographic appearance of a positive contrast agent in comparison to soft tissue?

Answer 168

Appear more radiopaque– higher atomic number

Question 169

What is used in bone scintigraphy?

Answer 169

Technetium methylene diphosphonate (MDP)- taken up by areas of active bone turnover

** bone scintigraphy is much more sensitive than radiography at detecting bone lesions but is relatively non-specific

Question 170

What is thyroid scintigraphy?

Answer 170

Technetium pertechnetate– trapped and concentrated by thyroid follicular cells, mimicking biological behavior of iodide

** useful to evaluate hyperthyroidism– determines whether cervical masses are thyroidal or non-thyroidal in origin… differentiates between bilateral and unilateral disease, detection of ectopic thyroid tissue, and functional metastic lesions

Question 171

What is portal scintigraphy used for?

Answer 171

Sensitive and specific for diagnosis of portosystemic shunts– even quantification of the severity of the shunt– Technetium is administered into either the colon or into the spleen where it is taken up by portal circulation

Question 173

What is computed tomography?

Answer 173

Cross sectonal imaging modality based on x-rays. It gives excellent contrast resolution compared with conventional radiography. Produces high detailed cross sectional images with no superimposition of overlying structures.

** Helical scanners are the preferred type of machine– newer helical CT scanners have multiple rows of detector arrays– multi-slice CT scanners have very rapid acquisition times

Question 175

Indications for a CT examination

Answer 175

* Superimposition of structures in radiography prevents identification of lesions

* Improved soft tissue contrast is required

* lesions are suspected but not demonstrated with conventional modalities such as radiology or ultrasound

** e.g. brain and spinal imaging (MRI is best however but CT is more sensitive than MRI at detecting early brain haemorrhage with trauma), nasal disease to avoid superimposition, Tympanic bulla (changes seen with otitis media for example), musculoskeletal imagine (bone loss, complex trauma e.g. pelvic fractures provides 3D reconstructions), thoracic imaging (pulmonary metastases), abdominal imaging, foreign bodies and draining sinuses (localisation of abscesses and foreign bodies)

Question 176

Answer 176

Excretory urography- to look for ectopic ureters and tumors and to evaluate kidney function

Question 177

Answer 177

Urethrocystogram

Question 178

What is magnetic resonance imaging?

Answer 178

* imaging of hydrogen atoms throughout the body– measures how hydrogen atoms are influenced by radiofrequency pulses

* Most common source is water

* MR images are based on the distribution of water and the interaction of water with its surrounding molecules

* MRI exploits the property of hydrogen as a magnetic dipole– the rotating positive charge of the hydrogen atom induces a magnetic field– thus hydrogen atoms have a magnetic moment (direction and strength of their magnetic field)– with a strong magnetic field– the magnetic moments of the hydrogen atoms align with the external magnetic field

Question 180

What is better about MRI? Problem with MRI?

Answer 180

* superior contrast resolution– for soft tissue especially neural or musculoskeletal tissue… sensitive to the detection of early lesions

** takes a long time so susceptible to motion artifact from respiration or peristalsis

** most pathologies involve increased water content (tumours, inflammation, oedema, infection) and MRI is highly sensitive at detecting most diseases

Question 182

DDX for abdominal pain?

Answer 182

ischemia, inflamm, distension, traction– FB obstruction, pancreatitis, obstructive neoplasm, biliary obstruction, etc.

Question 183

When does a patient need rehydration? Maintenance?

Answer 183

* Rehydration in response to e.g. interstitial dehydration due to increased losses from vomiting and diarrhoea, coinciding with reduced intake (inappetance)

* Maintenance– e.g. if he doesn’t eat/drink

Question 184

In a 25 kg dog. TBW? ICF? ECF?

If the animal has a PCV of 50%, what is the total intravascular blood volume of the dog?

Answer 184

TBW = 60% of 25 kg = 15 L

ICF = 40% of 25 kg = 10 L

ECF intravascular = 1.25 L

ECF interstitial = 3.75 L

** If PCV if 50%– the other 50% is water (plasma). The IV volume of water (plasma) is 1.25 L, so that means that PCV is also 1.25 L… therefore a total blood volume of 2.5 L (2.5 L, 10% of body weight)– clinically important in resuscitative fluid therapy where one sequentially boluses portions of blood volume at a time until targeted resuscitation goals are met.

Question 185

What would your fluid therapy plan be (type, amount, over what time, by which route)?

Answer 185

* Isotonic: LRS (Hartmann’s) or 0.9% NaCl because he is not acidemic already

* Amount:

• deficit = 25 kg * 0.5 * 1000 = 1250 mL, 52 ml/ hr + maintenance… maintenance= ((25*30) + 70)/24= 34 ml/hr. 86.2 ml/hr + ongoing losses… 28 ml/hr on going losses?? 114 ml/hr

Question 186

Why do many animals appear brighter at the vets?

Answer 186

* Stress response, catecholamine/ cortisol release

Question 187

Answer 187

B- mode

Question 190

Describe what would happen to the body water (how it would shift between compartments) in a patient in which you infuse a hypertonic fluid such as mannitol 25% or hypertonic saline 7%?

Answer 190

** water would shift into the IV compartment from both the interstitial and intracellular compartments– then as normal serum sodium concentration is re-established the balance between the ICF and ECF will normalize

Question 191

What is normal serum osmolality in cats? Dogs? What substances contribute to serum osmolality?

Answer 191

290- 310 mOsm/l in dogs; 300-310 in cats

* Serum osmolality = 2 (Na+K)+ glucose+ urea (in mmol/L)

Question 192

Answer 192

Spectral doppler

Question 193

Answer 193

Phased array

Question 194

What is osmolality?

Answer 194

* Final osmolality is the sum of the number of mmols solutes present in the bag. Irrespective of their size or charge, it is the simple sum

Question 195

What is a balanced fluid? What are others?

Answer 195

* LRS is balanced as it contains an electrolyte composition similar to serum

* 5% dextrose in water, 0.9% NaCl, 0.45% with 2.5% dextrose all non-balanced

Question 196

Calculate how many mls 50% dextrose you would add to a 1 L bag of LRS to make a 2.5% solution? What is the resultant osmolality?

Answer 196

Goal is 2.5% dextrose in 1000 mL.

* to convert any percentage to mg/ml just add a zero… so 2.5% solution is 25 mg/ml

* If you want a 2.5% solution, you need 25 mg/ml and since there are only 1000 ml in the bag of LRS, you would need 25,000 mg dextrose in 1 L total solution. Since 50% dextrose - 500 mg/mL, you would add 50 mL dextrose to your bag of LRS after removing 50 ml of the LRS

** The osmolality of 50% dextrose is 2780 mOsm/L, so 2.78 mOsm/ml… since you are starting with a bag of Hartmann’s which has 272 mOsm in it, and you took out 50 mls, you are left with a bag of 245 mOsm in it (272-(50*0.272))= 253 mOsm. Then you will add back in 139 mOsm from the dextrose (2.78 mOsm/ml x 50 ml = 139 mOsm), so 258 + 139 - 397 mOsm

Question 197

Before approving a veterinary radiation procedure, the veterinarian must take into account what three factors?

Answer 197

Need, safety for the animal, other options that do not involve radiation

Question 198

Which of the following best describes the radiation effects experienced during exposures made for diagnostic radiology?

Answer 198

DNA damage

Question 199

What ancillary positioning devices may be used?

Answer 199

Examples: sandbags, radioluscent pads, cassette holders, positioning troughs, other- compression bands

Question 200

In Victoria, the Radiation Act 2005 states that in order to operate an x-ray machine…

Answer 200

must have a user license

Question 201

What form of radiation x-rays take?

Answer 201

Ionizing electromagnetic radiation

Question 202

As specified by ARPANSA (The Australian Radiation Protection and Nuclear Safety Agency), the occupational radiation effective dose limit is:

Answer 202

20 mSv per annum over a period of 5 years

Question 203

What principles do we follow to minimise radiation exposure

Answer 203

Time (as few x-rays as possible), distance, and shielding

Question 204

What is the radiographic constrast? Subject contrast?

Answer 204

Number of shades of gray in an image

* Subject contrast- different tissues absorb a different amount of rays

Question 205

What is an artefact?

Answer 205

Something that is not real, NOT a microchip

Question 207

How do you achieve the best results in regards to geometric factors?

Answer 207

* select the smaller focal spot when possible (as the focal spot becomes larger the penumbra is increased because blurring of the edges)

* Keep FFD as large as possible (about 100 cm)– focal spot to film distance (closer the x-ray tube is to the film, the greater the image magnification and greater the penumbra)- improve image sharpness and reduces magnification

* keep the OFD as small as possible (object to film distance)– improves image sharpness and reduces magnification

Question 208

Example of positive contrast agents?

Is Helium a common example of a negative contrast agent?

Answer 208

* Positive contrast agents: barium and iodinated contrast agents

* Helium is NOT a negative contrast agent

Question 209

Mechanism of action of a postive radiographic contrast agent?

Answer 209

High Atomic number is an efficient absorber of photons

Question 210

What is the main route of excretion of barium? Main route of excretion of iodinated contrast agents?

Answer 210

* Barium is mainly excreted through faeces

* Iodinated contrast agents are mainly excreted through urine

Question 211

What is the major difference between an ionic and non-ionic contrast agent?

Answer 211

Ionic agents have high osmolality which have adverse reactions– nauseau and vomiting.

* The iodinated anion is really the only part of the molecule that is important for radiographic purposes, both the anion and cation are osmotically active and when they dissociate in solution, tend to thave osmolalities double that of equivalent non-dissociating non-ionic compounds

Question 212

Excretory urogram, what is the most appropriate contrast agent to use?

Answer 212

Iodinated- non-ionic agents reduce the incidence of contrast media induce nephrotoxicity (CMN) in excretory urograms

Question 213

What is the most appropriate contrast agent for a myelogram?

Answer 213

Non-ionic iodinated– seizures, hyperthermia, prolonged recovery from anaesthesia, and intensification of pre-existing neural signs are postmyelographic effects commonly reported in dogs. Neurotoxicity of contrast media as well can occur– direct chemotoxic effects on neural tissue and their hyperosmolality

Question 216

Appropriate choice of contrast agent for performing a contrast study in a patient with suspected gastric wall mass

Answer 216

Barium

Question 217

Appropriate medium to evaluate ureters in a young cat with abdominal trauma

Answer 217

Excretory urogram

Question 218

Most appropriate diagnostic imaging test to evaluate kidneys with chronic renal failure?

Answer 218

Ultrasound

Question 219

Most appropriate agent to use in a patient suspected to have an oesophageal FB and oesophageal perforation?

Answer 219

Non-ionic iodinated

Question 220

What potential complication may occur when performing a pneumocystogram in a patient with haematuria?

Answer 220

Air emboli

Question 221

What is an example of an adverse reaction that may occur following intravaneous injection of iodinated contrast media?

Answer 221

Renal failure

Question 222

What is the major cause of hypotension observed following intravenous injection of iodinated contrast agent?

Answer 222

Osmolality

Question 223

Prior to performing an excretory urogram, which of the following options lists the most appropriate tests to evaluate the risk of an adverse reaction to IV injection of an iodinated contrast agent?

Answer 223

Biochemistry and urinalysis

Question 224

True or false: Perivascular injection of an ionic iodinated contrast agent may lead to sloughing of the skin?

Answer 224

True

Question 226

Which of the following statements is true of diagnostic ultrasound?

A. The ultrasound machine assumes sound travels faster in fat than in the liver

B. Diagnostic ultrasound uses sound frequencies of between 1 and 10 Hz

C. The wavelength of sound is inversely proportional to the frequency

D. Ultrasound probes continuously produce sound and receive echoes to form the B-mode image

Answer 226

C. The wavelength of sound is inversely proportional to the frequency

Question 227

What circumstances will produce an ultrasound image with the best possible spatial resolution?

* high frequency transducer

* imaging with a low gain setting

* low frequency transducer

* imaging within the focal zone

* high dynamic range

Answer 227

* High frequency transducer, imaging within the focal zone

Question 228

Physical properties that influence the rate at which sound is attenuated as it passes through the body?

Answer 228

Irregular surfaces and different tissue interfaces (NOT frequency and distance travelled– they are not physical properties)

Question 229

Most appropriate use of transducer to use when imaging structures deep within the abdomen

Answer 229

Low frequency

Question 232

Purpose of applying gel to skin?

Answer 232

Better sound transmission so it can glide

Question 233

In B-mode ultrasound imaging, what does the brightness of a pixel on the display indicate?

Answer 233

Amplitude of each returning echo, low intensity echoes are black and high intensity echoes are white

Question 234

T or F: Ultrasound is very specific for identifying what disease is present?

Answer 234

False

Question 235

Answer 235

Question 236

Answer 236

Question 237

Answer 237

Question 238

What is a morgan line?

Answer 238

Femoral head/neck exostoses - may be a thin line of enthesophytes on the caudal aspect of the femoral head (Morgan line or “caudolateral curvilinear osteophyte”…even though it’s really an enthesophyte)

Question 239

Answer 239

Question 240

Answer 240

Question 241

What are the most common sites of IVD herniations– type I in large dogs?

Answer 241

T11-12, T12-13, T13-L1 and L1-L2. The intercapital ligament prevents extrusion of the nucleus pulposus in the cranial and midthoracic IVDs.

Question 242

Answer 242

Question 243

Answer 243

anisokaryosis within the one cell

Spindle appearance– meschenchymal cells seen individually and in small bundles

* Spindyloid with pale round to oval nuclei with some binucleation

* Soft tissue sarcoma- locally aggressive but rarely metastasize, concerned it may be more aggressive. Histopathology is required for grading

Question 245

6 yo MN Golden Retriever

Hx: would not get up from his bed this morning and not interested in food. Has been quiet the past few days.

PE: HR 112, RR 20, Pale MMs. CRT < 2 seconds. T 39.6C.

Decreased Hb, Decreased Ht, Decreased RCC, Increased MCV, Increased MCH, Decreased MCHC, Neutrophilia*, Monocytosis*, NRBC- 17, Increased reticulocytes, Total bilirubin increased

1. Why has the WBC been corrected?
2. Analyser count accurate? No.
3. Morphological abn?
4. Error flag for PLT count?
5. Characterise the anaemia?
6. Most likely cause of haematology abnormalities?
7. Potential causes of mild elevation in ALP?

Answer 245

1. Why has the WBC been corrected? Due to the presence of NRBC using the formula:

Corrected WBC= (WBCx100)/ (100+NRBC)

2. Is the analyser differential count accurate?

NO. Bands are included with normal nuetrophils, high monocytes

3. Morphological abn?

Leukocytes- left shift and toxic change. Occasional activated lymphocytes (after they bind to an antigen– they are activated).

Erythrocytes- agglutination, spherocytosis, anisocytosis, macrocytosis, polychromasia.

4. Error flag for PLT count? Clumping
5. Characterise the anaemia?

Moderate macrocytic hypochromic anaemia that is markedly regenerative.

6. Macrocopic agglutination in blood tube
7. Most likely cause of haematology abn?

IMHA would account for the regenerative anaemia with normal protein, spherocytosis and agglutination. The metarubricytosis is likely secondary to the regenerative response.

8. ALP- sources of ALP include hepatocytes and biliary epithelial cells, bone, gut, placenta, and corticosteroid induction in dogs. The elevation in this case could reflect mild cholestasis or corticosteroid induction (endogenous or exogenous).

IMHA tests–

: CBC, Biochemistry, Blood Gases, PCV/TP, Blood Smear, Saline auto-agglutination, (Direct Coomb’s test), Blood Pressure, Coagulation profile, urinalysis (haemoglobinuria- intravascular haemolysis OR bilirubinuria), May be second line, though highly suspicious: infectious titers/ PCR testing: Idexx panel– tick/vector canine comprehensive Real PCR panel (Anaplasmosis, Babesia, Mycoplasma - depends on your area), (ELISA for heartworm antigen- depends on where you are)

** Essential to look for underlying disease process in order to correct or to R/O if primary IMHA

–Coomb’s test- agglutination of RBCs after the addition of an antibody mixture to the patient’s blood. Antibodies in the mixture will bind to Ig or Complement proteins as they are bound to the RBCs. Serial dilutions of the antibody mixture are added to the patient’s blood to quantify the degree of agglutination. False positives and false negatives may be frequently observed if post transfusion or other disease process.

Question 246

What is toxic change in a neutrophil?

Answer 246

Morphological abnormalities acquired during maturation under conditions that intensely stimulate neutrophilc production and shorten the maturation time in the boen marrow.

This accelerated maturation occurs secondary to cytokine stimulation, which is usually in reponse to inflammation. Animals recovering from bone marrow injury or who are administered hematopoietic cytokines (e.g. granulocyte-colony stimulating factor or G-CSF) can also show accelerated maturation in neutrophils or toxic change. On the standard hemogram, the presence of toxic change is reported under the WBC exam section and is subjectively graded as mild, moderate and marked. Most of the toxic changes reflect asynchrony of maturation between the nucleus and cytoplasm.

Question 247

Answer 247

EDTA

* Routine haematology in mammals

* Routine fluid cytology

* Endogenous ACTH, Cyclosporin, PCR tests, genetic tests, Catecholamines, Lead

* NOT suitable for most biochemistry assays

* NOT suitable for culture

* Na/K EDTA irreversibly chelates calcium preventing clotting

Question 248

Answer 248

Heparin

* Routine biochemistry

* Ammonia

* Routine haematology and biochemistry in avians and reptiles

* NOT suitable for most serology

** Sodium heparin inhibits clotting through activation of antithrombin III

Question 249

Answer 249

Serum

* Routine biochemistry

* Drugs (gel tubes may be unsuitable)

* Serology

* Hormones

* Protein electrophoresis

* Sterile plain tubes for fluid culture and cytology (NOT SST or gel tubes)

** Gel aids separation from cells from serum

Question 250

Answer 250

Fluoride Oxalate

* Glucose

* L-lactate

* Not suitable for routine biochemistry or haematology

** Sodium Fluoride/ Potassium Oxalate– stops erythrocyte utilisation of plasma glucose. Binds calcium to prevent coagulation.

Question 251

Answer 251

Citrate

* Coagulation testing e.g. PT, APTT, Fibrinogen, FVIII, FIX, VWF

* Haematology (need to correct for dilution)

* Blood products

** Sodium citrate inhibits coagulation through binding of calcium, must be filled with correct blood volume

Question 252

Answer 252

Question 253

13 yo female neutered DSH

Hx: Vomiting daily for the last 5 days, diarrhoea last few weeks. Weight loss.

PE: HR 148, RR 20. Mild splenomegaly and discomfort on abdominal palpation.

High monocytes, low platelets

High urea, hypocalcaemia, hypoalbuminaemia

1. What is unual about the WBC scattergram?
2. Monocytosis actually present?
3. Accurate count? No.
4. What morphologic abn. can you ID in the leukocytes and erythrocytes?
5. Hypocalcaemia– significant in this case?
6. Tests for further workup?
7. Most likely cause?

Answer 253

1. Scattergram- broad monocyte cloud which is merging with the eosinophil cloud. Slight merging of the neutrophil and lymphocyte clouds. Suggest the differential list is likely to be inaccurate.
2. May be large round cells with variable numbers of deeply purple large cytoplasmic granules. Mast cells. Due to merging of eosinophil cloud may also be counting the eosinophils as monocytes.
3. No– abn– band neutrophils, eosinophils, mast cells, basophils
4. Leukocytes- left shift and mild toxic change. Occasional neutrophils containing purple cytoplasmic granules (likely phagocytosed mast cell granules). Rare activated lymphocyte.

Erythrocytes- rouleaux, mild anisocytosis.

6. Hypocalcaemia likely to reflect hypoalbuminaemia (reduced protein bound fraction). Can further assess my measuring ionized Calcium. hypoalbuminaemia could reflect GI loss, renal loss, or reduced synthesis due to inflammation (negative acute phase inflammation)
7. Tests to further workup– Abdo U/S to further assess liver and spleen, and FNA/biopsy of any suspect lesion. Check for cutaneous masses and GIT bleeding (GIT ulceration can occur secondary to MCTs due to histamine release). Ionized calcium.
8. Most likely visceral or disseminated MCT (splenic or multiple organs) if no cutaneous massess present– depression, anorexia, weight loss, vomiting. More commonn in cats compared to dogs.

Question 254

6 yo female neutered Beagle with shifting lameness. You notice she has swollen carpi and hocks. The dog also has a mild fever and a grade 2/6 heart murmur.

1. Primary DDX
2. What tests would you consider and what samples should be collected for these tests?

Answer 254

6 yo female neutered Beagle with shifting lameness. You notice she has swollen carpi and hocks. The dog also has a mild fever and a grade 2/6 heart murmur.

1. Primary DDX
2. What tests would you consider and what samples should be collected for these tests?
3. Immune mediated polyarthritis- inflammatory, erosive (Grey Hounds, Mycoplasma?), Rheumatoid or non-erosive (idiopathic, diag. of exclusion, secondary to remote infection, GI disease, Neoplasia (type 4, rare), SLE (body attacks nucleated cells, why it is diffuse), drugs- sulfonamide), Breed related– secondary to renal failure and amyloidosis…. may be accompanied by glomerulonephritis, anaemia, thrombocytopaenia, leukopaenia, retinitis, myositis, aseptic meningitis. Another DDX- Coagulopathy (heart murmur). Multiple Myeloma.
4. Arthocentesis- Markedly elevated cell count (4-350 x 10^9/L, mostly neutrophils)– submit for culture, negative result does not rule out septic arthritis (Mycoplasma), FOUR JOINTS. Infectious arthritis v. autoimmune. Joint fluid is really hard to grow bacteria. (joint tap—plain, serum, EDTA—not EDTA for culture—one drop—smear—then swab into jelly material—discuss with a pathologist on how to best use)

* Antibody- Anti ANAs- plain tube. Serum testing.

* Synovial biopsy especially if difficulty obtaining joint fluid

* Blood culture- expensive bottles and expire—surgical prep (under GA). Send away for culture. 2-3 samples. Good for multiple resistant infections if you’ve tried multiple antibiotics with no luck.

* Radiography of joints– mineralisation of periarticular tendons and ligaments– after several weeks of erosive forms

* Osteosarcoma- FNA (18 G needle, 70-80% of the time diagnostic or Radiographs can help)

Question 257

Terry 8 yo MN Staffy

Hx: Weight loss and diarrhoea despite good appetite. Slowing down last few months.

PE: HR 94, RR 16. Pink MMs, CRT < 2 seconds. T 37.8C

High WBC. High LYM, Low Eosinophils.

1. DDX for lymphocytosis?
2. Significant numbers of granular lymphocytes. Describe the morphology.
3. Eosinopenia… why does the scattergram indicate this is incorrect?
4. Most likely cause of haematological abn?
5. What other tests?

Answer 257

1. Neoplasia: Chronic lymphocytic leukaemia can occur in an animal of any age… Thymomas have also been associated with peripheral lymphocytosis.

Infectious agents: Ehrlichia canis- granular lymphocytosis in the bloood, not in AUS

Endocrine: Hypoadrenocorticism can result in lymphocytosis, but this is usually mild.

Physiologic: Excitement can result in lymphocytosis, usually mild and occus more commonly in young animals, cats, and horses.

2. Significant numbers of granular lymphocytes. Describe the morphology.

Granular lymphocytes are intermediate lymphocytes with round nuclei of clumped chromatin, occasionally showing with a faint nucleolus and abundant pale cytoplasm, often containing a cluster of fine pink-purple granules. These lymphocytes are not usually foudn in the circulation in such high numbers and are therefore classed as atypical.

4. Eosinopenia… why does the scattergram indicate this is incorrect?

Neutrophiil and eosinophil clouds are not well separated.

6. Most likely cause of haematological abnormalities?

HIgh number of these cells and their monomorphic morphology strongly supports a granular lymphocyte lymphoic leukaemia or a stage V granular lymphocyte lymphoma. In dogs, cells with this morphology are often of splenic rather than marrow origin. Their size, clumped chromatin and indistinct nucleoli suggests this is more likely to be a chronic lymphocytic leukaemia rather than an acute lymphoic leukaemia. The cytoplasmic granules support either T cell or NK cell origin.

7. What others tests?

Question 258

11 yo MN wire haired Fox Terrier

Hx: Two possible seizures today where he collapsed and appeared unaware, no prior episodes. Fully vaccinated.

PE: HR 148 bpm with grade II/VI systolic murmur, RR 32 bpm, pale MM, CRT 1.5 seconds, T 38.3C. Neuro exam unremarkable.

Low RCC, Low Hb, Low PCV, High MCV, Low MCHC (reticulocytes are large cells, immature, less Hb), Neutrophilia, NRBC, Reticulocytosis, high CK

1. Is the anaemia regenerative or non-regenerative?
2. What RBC morphologic changes can you ID on the blood smear?
3. What is the likely mechanism for the anaemia?
4. What are the potential causes for this disorder?

Answer 258

1. Is the anaemia regenerative or non-regenerative?

Regeneratie– moderate macrocytic hypochromic anaemia that is mildly regenerative as there is a reticulocytosis and polychromasia is evident on the blood smear.

2. What RBC morphologic changes can you ID on the blood smear?

Eccentrocytes (up to 25% of erythrocytes), occasional large Heinz bodies, polychromasia, anisocytosis, macrocytosis, pyknocytes (resemble spherocytes but with a small membrane tag)

3. What is the likely mechanism for the anaemia?

Oxidative injury causing haemolytic anaemia.

4. What are the potential causes for this disorder?

Question 259

11 yo FN Labrador Retriever

Hx: Presented for removal an of eyelid mass which has been irritating her for a few weeks
PE: Overweight. Generalised lymphadenopathy. Small mass on left upper eyelid (suspected Meiobomian gland adenoma)

Low RCC, Low Hb, Low Hct, Low MCHC, Markedly High WCC, Neutrophilia*, Lymphocytosis*, Monocytosis*, Low glucose, High ALT, High ALP, High GGT

1. What is abn about the histogram?
2. What are the potential causes for a marked lymphocytosis? Which is more likely in this case and why?
3. What are the potential mechanisms for thrombocytopaenia? Which is most likely?
4. Why might Kelly have hepatopathy?
5. Potential causes for hypoglycaemia?
6. What are the potential causes of anaemia? Characterise from smear.
7. How would you further assess this case?

Answer 259

1. What is abn about the histogram?

Intermediate to large atypical mononuclear cells present. Round nuclei of granular chromatin with 1-3 variably distinct nucleoli and moderate amount of deep basophilic cytoplasm, resembling intermediate to large lymphocytes. Occasional mitotic figures are evident along with frequent basket cells. It is likely that many of these atypical cells are being counted as monocytes and neutrophils based on their large size.

2. What are the potential causes for a marked lymphocytosis? Which is more likely in this case and why?

Stage V Lymphoma- most likely given the peripheral lymphadenopathy and magnitude of lymphocytosis

* Lymphoid leukemia- in this case lymphadenopathy suggests LN origin (ie lymphoma) is more likely than bone marrow origin (ie leukemia)

* Myeloid Leukaemia- both myeloid and lymphoid leukaemias can have similar cytomorphology

* Inflammation- not at this magnitude of lymphocytosis

* Physiologic- not at this magnitude of lymphocytosis and unlikely in an adult dog

* Endocrine- hypoadrenocorticism- not at this magnitude of lymphocytosis

3. What are the potential mechanisms for thrombocytopaenia? Which is most likely?

Reduced bone marrow production due to myelophthisis- most likely given the marrow is likely heavily infiltrated with the lymphoma

Sequestration- seen with splenomegaly and splenic masses

DIC- can be a complication of lymphoma

IMTP- can be a complication of lymphoma but less likely as they often present with much lower counts and mucosal bleeding (petechiation)

4. Why might Kelly have hepatopathy?

Likely reflects infiltration of the liver with neoplastic cells

5. Potential causes for hypoglycaemia?

Paraneoplastic syndrome, Storage artefact- utilisation of glucose by erythrocytes and leukocytes, Hypoadrenocorticism, Hepatic disease- other functional parameters are normal so less likely (ie cholesterol, albumin, urea)

6. What are the potential causes of anaemia? Characterise from smear.

* Mild polychromasia and thus anaemia is likely mildly regenerative and hence could reflect:

• blood loss e.g. mucosal bleeding secondary to thrombocytopenia- often not seen until PLT count < 30 x 10^9/L
• blood loss- coagulopathy secondary to liver disease (unlikely to be hepatic failure but consider PT/APTT to further assess)
• Haemolysis- IMHA can be triggered by lymphoma- no evidence on the smear
• Haemolysis- microangiopathic e.g. DIC- no evidence of shear injury on the smear but worthwhile to check PT and APTT and if available D-dimers (fibrin degradation product, a small protein fragment present in the blood after a blood clot is degraded by fibrinolysis. It is so named because it contains two D fragments of the fibrin protein joined by a cross link) or FDPs (fibrin degradation product- components of blood produced by clot degeneration) given the thrombocytopenia

** Reticulocyte count manual or automated in order to assess if regenerative

7. How would you further assess this case?

Question 261

8 yo MN Blue Heeler

Hx: Lethargy over past few weeks. Intermittent pasty dark diarrhoea. Mild weight loss.

PE: Pale MMs, HR 132 with grade 1/6 systolic murmur, RR 24, Thin BCS 3/9. T 38.1C. Mild abdominal discomfort on palpation.

1. Evaluate the blood smear. What erythrocyte morphologic abn can you ID?
2. What is RDW-SD and how does this help us evaluate an anaemia?
3. Describe the anaemia. DDX?
4. Compare the patient RBC/PLT scattergram with the normal dog scattergram. What does Bluey’s scattergram suggest?
5. What is PDW and MPV? What the increases in these values reflect?
6. What are your DDX for the azotaemia? How could you further evaluate this patient?

Answer 261

1. Evaluate the blood smear. What erythrocyte morphologic abn can you ID?

Microcytes, hypochromasia, polychromasia, keratocytes, schistocytes, dacrocytes, rare spherocytes

2. What is RDW-SD and how does this help us evaluate an anaemia?

RDW-SD= red cell distribution width std deviation (a measure of erythrocyte anisocytosis). An increase could reflect macrocytosis, microcytosis or both. The low MCV with high RDW-SD and reticulocytosis suggests both microcytosis and macrocytosis are likely in this case.

3. Describe the anaemia. DDX?

Moderate microcytic hypochromic regen. anaemia. Marked reticulocytosis– regenerative. Haemorrhage or haemolysis. The low protein suggests haemorrhage is much more likely.

Microcytosis is seen with iron deficiency, or with portosystemic shunts, and can also be normal in some Asiatic breeds eg Akita, Chow Chow, Shiba Inu

Given the regen. anaemia is microcytic and there are GIT signs than iron deficiency due to chronic GIT haemorrhage is most likely. The schistocytes, keratocytes, etc. support microvascular damage to erythrocytes which is likely to reflect increased cell fragility due to iron deficiency in this case.

4. Compare the patient RBC/PLT scattergram with the normal dog scattergram. What does Bluey’s scattergram suggest?

The erythrocytes and reticulocytes have merged with the platelets in the scattergram. The reason the populations have merged is that the microcytosis and presence of macroplatelets has meant that the erythrocytes and platelets are similar in size.

5. What is PDW and MPV? What the increases in these values reflect?

PDW= PLT distro width (a measure of platelet anisocytosis)

MPV= mean PLT volume

IN this case the high PDW and MPV suggest macroplatelets are present

6. What are your DDX for the azotaemia? How could you further evaluate this patient?

There is a mild increase in urea only with the creatinine being low normal. This suggests prerenal azotaemia is most likely. Potential causes include dehydration, increased protein breakdown, hypovolaemia.

GIT haemorrhage leads to increased protein in the GIT and mimics the effect of a high protein diet. IN this case the GIT bleeding is likely the cause of the high urea. Dehydration is usually associated with increased Hct, increased TP, and increased Na and Cl. In this case Na and Cl are normal. Looking at Hct and TP in this case for evidence of dehydration is problemative as the bleeding is likely making these values low.

Question 262

6 yo FN DLH Cat

Hx: Vomited numerous times overnight and now depressed and weak

PE: HR 99 bpm, RR 24 bpm, T 37.3C. Pain on abdo palpation. Small soft bladder.

1. Eval the leukocyte scattergram for Misty vs. normal cat.
2. The analyser flagged the PLT results. Eval PLT histogram– what are the potential causes for the elevation from the baseline?

Answer 262

1. Eval the leukocyte scattergram for Misty vs. normal cat.

There is merging of the lymphocyte and neutrophiilc clouds and thus the differential may be inaccurate. THis is usually due to the presence of immature neutrophils (bands and neutrophils with toxic change which leads to higher fluorescence of these cells). This is confirmed on the smear as there is a significant left shift and toxic change, consistent with a marked inflammatory response.

2. The analyser flagged the PLT results. Eval PLT histogram– what are the potential causes for the elevation from the baseline?

The elevation from baseline indicates overlap of the PLT and RBC histograms. This could reflect the presence of macroplatelets, microcytic erythrocytes or platelet clumping. The MCV is normal, only occasional macroplatelets are evident and small PLT clumps are present in the feathered edge– the PLT clumping is likely a result of the abn histogram.

Question 268

1 yo Dobermann dog entire with epistaxis

1. Questions to ask the owner
2. Primary DDX
3. Tests would you consider and samples to be collected

Answer 268

6 yo female neutered Beagle with shifting lameness. You notice she has swollen carpi and hocks. The dog also has a mild fever and a grade 2/6 heart murmur.

1. Primary DDX
2. What tests would you consider and what samples should be collected for these tests?
3. Immune mediated polyarthritis- inflammatory, erosive (Grey Hounds, Mycoplasma?), Rheumatoid or non-erosive (idiopathic, diag. of exclusion, secondary to remote infection, GI disease, Neoplasia (type 4, rare), SLE (body attacks nucleated cells, why it is diffuse), drugs- sulfonamide), Breed related– secondary to renal failure and amyloidosis…. may be accompanied by glomerulonephritis, anaemia, thrombocytopaenia, leukopaenia, retinitis, myositis, aseptic meningitis. Another DDX- Coagulopathy (heart murmur). Multiple Myeloma.
4. Arthocentesis- Markedly elevated cell count (4-350 x 10^9/L, mostly neutrophils)– submit for culture, negative result does not rule out septic arthritis (Mycoplasma), FOUR JOINTS. Infectious arthritis v. autoimmune. Joint fluid is really hard to grow bacteria. (joint tap—plain, serum, EDTA—not EDTA for culture—one drop—smear—then swab into jelly material—discuss with a pathologist on how to best use)

* Antibody- Anti ANAs- plain tube. Serum testing.

* Synovial biopsy especially if difficulty obtaining joint fluid

* Blood culture- expensive bottles and expire—surgical prep (under GA). Send away for culture. 2-3 samples. Good for multiple resistant infections if you’ve tried multiple antibiotics with no luck.

* Radiography of joints– mineralisation of periarticular tendons and ligaments– after several weeks of erosive forms

* Osteosarcoma- FNA (18 G needle, 70-80% of the time diagnostic or Radiographs can help)

Question 270

6 yo neutered female Springer Spaniel with malaena, pale MM, lethargy

1. Questions to ask the owner?
2. Potential causes of malaena?
3. Further tests?

Answer 270

1. Questions to ask the owner?
2. Potential causes of malaena? Ulcers in GIT, tumors or oesophagus or stomach, infections, FB in GIT, Disorders involving inflammation of the intestinal system, kidney failure, drug toxicity, diet with raw food
3. Further tests? Low RCC, Low Hb, Low Ht, High Urea, Low PLT (9!), Neutrophiilia, Lymphopaenia, Monocytosis, Reticulocytosis, Low TSS, Low TP

** consistent with GI bleed– stress leukogram.

** Ensure not associated with coagulopathy– Coagulation panel

* Confirm GI bleeding exists

* Is the cause ulcer or numerous erosions that cannot be resected?

* Determine underlying cause?

Abdominal radiographs generally do not help diagnose GI ulceration, but they can help exclude GI obstruction, intussusceptions, and peritonitis. Abdominal ultrasonography may show abnormalities in GI wall thickness or presence of a mass, but its primary utility is the identification of non-GI lesions. Endoscopy allows visualization of the esophagus, stomach, duodenum, and colon and identification of mucosal lesions and ulcers. Endoscopy also allows for fine-needle aspirates of lesions or collection of biopsy samples, although full-thickness surgical biopsies may be required to identify infiltrative disease and tumors. Ulcerated areas should be biopsied only on the periphery to avoid perforation. Gastric fluid can be tested for pH to help diagnose hypersecretory states.

** Blood smear– microcytic, hypochromic anaemia (iron deficiency anaemia), takes time to develop so may be normocytic, normochromic.

BUN to Creatinine ratio has been reported with GI haemorrhage especially with upper GI haemorrhage… not always the case.

** Faecal occult blood test can be performed. False positive can occur due to eating of meat or certain types of bacteria within the GIT. Meat free diet for 72 hours before faecal occult blood test.

** ACTH, CBC, biochem, imaging and endoscopy to determine underlying… coag profile may identify rodenticide toxicity or clotting factor deficiencies)

Question 275

2 yo Male Cairn Terrier

Hx: Two week history of intermittent anorexia and vomiting. Has had a number of seizures in the past two days. Has just recovered from a seizure.

PE: HR 120, CRT 2 seconds, RR 24, T 37.8. Quiet and responsive

Low RCC, Low Hb, Low Hct, Increased RDW-SD, low PDW (platelet distro width), low MPV (MPV is higher when there is destruction of platelets), NRBC, ALP increased, increased CK

1. Is the mild anaemia regenerative or non-regenerative? What erythrocyte morphologic abnormalities can you ID in the blood smear?
2. What are the potential causes for the increased nucleated RBCs?
3. Why has the WBC count been corrected?
4. What further tests?

Answer 275

1. Is the mild anaemia regenerative or non-regenerative? What erythrocyte morphologic abnormalities can you ID in the blood smear?

The mild normocytic normochromic anaemia is non regenerative as there is no polychromasia/ reticulocytosis. There is metarubricytosis (immature erythrocytes and their release into the blood– called polychromasia– due to lead toxicity, phosphofructokinase deficiency, anaemia) and basophilic stippling.

2. What are the potential causes for the increased nRBCs?

* As there is no polychromasia/ reticulocytosis this is not part of the regenerative response thus is termed inappropriate metarubricytosis. Potential causes include lead poisoning, heat stroke/ hyperthermia, splenic disease, sepsis, inflammation, dyserythropoeisis e.g. erythroid leukaemia, myelodysplastic syndrome (a group of cancers in which immature blood cells in the bone marrow do not mature and therefore do not become healthy blood cells).

3. Why has the WBC count been corrected?

Analysers utilising impedance counts include the NRBCs as leukocytes. We can correct the WBC count with:

Corrected WBC= (WBC x 100)/ (100+NRBC)

4. What further tests?

Question 276

Answer 276

• D. Clenbuterol (Tocolytic) Beta2 adrenergic receptor agonists- acts on vascular smooth muscle, myometrium, and the bronchial tree
• Uterine pushing-under hormonal control
• Abdominal pushing- under reflex, skeletal muscles
• You must give an epidural and tocolytic if you want to stop– not common to have to give both– so the epidural stops her straining. Don’t reach for tocolytic too quick because you can use her uterine pushing for her to help after your reposition.
• Don’t use xylazine- uterotonic- harder to get the uterus up to your surgical site. She may also sit down. (same with Ace, PGF2alpha- uterotonic)

Question 277

Answer 277

b. ocular menace reflex- takes time to develop (learned response) and can’t see the response, dark in there

Question 278

Answer 278

D. Radial Nerve paralysis- rolling on the front foot, drag their foot and throw their front limb forward with their shoulder– damage with any short of trauma to the shoulder– recumbency can damage the radial nerve as well from doing the forelimb splits (damage the brachial plexus)

Question 279

Answer 279

Sciatic Nerve

Can end up with peroneal (upside down P) or tibial nerve damage (upside down T)

Question 280

Answer 280

• Long acting corticosteroids used to induce parturition impair the secretion of proteins that are critical to normal cellular and hormonal immune responses, an effect that is strongly linked with changes in the composition of the WBCs. The resulting immune suppression is still profound at the time of parturition
  
  • Increased incidence of RFMs when induced to calve (long acting produce lower incidence of RFMs compared to short acting corticosteroids or prostaglandins)
  • Increased incidence of mastitis especially coliform mastitis endotoxaemia, peracute metritis, septicaemia, enteritis
  • Photosensitivity reaction can occur in the non-pigmented skin and teats of induced cows, in some cases can be severe enough to preclude milking. CS used to induce parturition MAY lead to hepatic damage
  • Premature calves reduced chances of survival however most studies report that when calving is induced using short acting CS or PGs within two weeks of term, little difference is seen in the number of stillbirths, calf vigour or calf mortality compared with natural calves except when Long acting CS’ have been previously used (gestation 283 days, 9.3 months)
  • Blood in milk is probably the least likely….

Question 281

Answer 281

c) Penethamate hydrochloride- APVMA - register drugs in AUS

** Care with using intramammary antibiotics as if the milk is gluggy may not penetrate teat canals well– may need systemic antibiotics even if she is not systemically unwell

Question 282

Answer 282

a) insufficient fibre in the herd’s diet- increases acetate and butyrate- milk production is less but butterfat concentration is higher (vs. higher energy (concentrates) means more proprionate– more glucose, lactose, more volume)– milk production will go down but quality goes up– most farmers are paid on butterfat content

(b- insufficient energy in a cows diet– butterfat and milk concentration will actually go up, c- excessive VFAs (acetate, butyrate, proprionate (further broken down into lactose– draws water into udder and increases volume of milk, ketones, glucose) fed to the cows– product of rumen digestion, cows make VFAs, e- inadequate rumen bypass protein in the concentrate ration– bacteria break down protein and use it themselves but by products of amino acids which is how the cow gets protein, d- excess ionophores in the concentrate ration would kill cattle just like horses)

Question 283

Answer 283

c) Phenylbutazone- look it up in MIMs

Question 284

Answer 284

e) Eimeria zuernii

Severely affected cattle develop thin, bloody diarrhea that may continue for >1 wk, or thin feces with streaks or clots of blood, shreds of epithelium, and mucus. They may develop a fever; become anorectic, depressed, and dehydrated; and lose weight. Tenesmus is common because the most severe enteritis is confined to the large intestine, although pathogenic coccidia of cattle can damage the mucosa of the lower small intestine, cecum, and colon.

Question 285

Answer 285

d) Fibrinogen

Question 286

Answer 286

a) Plain tube

Question 287

Question 288

Question 289

Answer 289

b) Staph epidermidis

Question 290

Answer 290

e) Anthrax

Question 291

Answer 291

d) 6 days– more than 60 hours

Question 292

Answer 292

b) Progesterone

Question 293

Answer 293

e) Pasture bloat

Question 294

Answer 294

b) 1.0 ml

Question 295

Answer 295

e) Flaccidity of the tail

Question 296

WHAT IS BACTOSCAN AND THERMODURIC?

Answer 296

Bactoscan- up to 200,000 premium milk with bonus 1 cent per litre, > 400,000 penalized 10%, >600,000 for more than a couple of weeks 30 cent penalty (depends on the company)

* Thermoduric- 600, OK

Question 300

What is the 3 week submission rate? What is the conception rate?

Answer 300

3 week submission rate dependent on heat detection and oestrous

Question 301

Aims for repro for individual cows

Answer 301

Question 302

Seasonal herd aims for repro performance

Answer 302

Question 303

What is the NRR?

Answer 303

Question 304

Common causes of repro problems in dairy cows

Answer 304

Question 305

Maximizing conception rate and service rate

Answer 305

normal heifer replacement rate- 20-25%

Question 306

What is proximal regional anaesthesia? Which vertebrae?

Answer 306

Question 307

Which side is blocked with the paravertebral technique?

Answer 307

Question 308

What is the distal paravertebral block?

Answer 308

Distal paravertebral block

Indicated for same as proximal paravertebral block

• The dorsal and ventral branches of the spinal nerves T13, L1 and L2 are desensitized at distal ends of L-1, L-2 and L-4.
• A 7.5-cm, 18-gauge needle is inserted ventral to tips of respective transverse processes in cows - approx 10-20 ml of a 2% lidocaine solution injected in a fan-shaped infiltration pattern.
• Needle completely withdrawn and reinserted dorsal to transverse process, where the cutaneous branch of dorsal branch is injected with about 5 ml of the analgesic.
• Procedure repeated for the second and fourth lumbar transverse processes.

10-20 ml 2% lidocaine is used per site and onset and duration similar to

proximal technique.

Question 309

Advantages of regional anaesthesia inverted L?

Answer 309

Question 310

Advantages and disadvantages of proximal paravertebral, distal paravertebral, infiltration anaesthesia, and inverted L or 7 block?

Answer 310

Question 329

When do you have a mastitis problem?

Answer 329

> 5% new cases every month

17 cases/120 milkings/ period of time

* 2-3 squirts of milk– if you still have changes in the milk 3-4 squirts in, she has mastitis

Question 330

5 Major Pathogens in Mastitis

Answer 330

Strep uberis, Strep agalatia, strep dysgalactia, Staph aureus, Coliforms (e. coli, Klebsiella)

Question 332

Put in the order the Australian domestic consumption (kg/year/person)? Pigs, Poultry, Beef, Small Ruminants

Answer 332

Poultry (41.7)

Beef (34)

Pigs (25.5)

Small Ruminants (10.4)

Question 333

T or F: All carcasses are swabbed for bacteria (under the E. coli and Salmonella Monitoring program) and tested for pesticide and veterinary medicine residues (under the National Residue Survey).

Answer 333

False: Carcasses are randomly selected for testing under these programs

Question 334

Functions of veterinarians in the meat production and processing sector relate to seven (7) areas. These are

1. Protection of human health
2. Maintenance of export markets
3. Enhancement of consumer confidence
4. Assuring animal welfare
5. ____________________________________
6. Improvement of meat quality and profitability
7. Management of processing staff

Answer 334

Surveillance for notifiable diseases and biosecurity.

Question 335

The principle document that governs international agreement on what constitutes safe food is called the

Answer 335

Code Alimentarius

Question 336

On-going changes to Australia’s meat inspection system reflect the need to

Response

Your answer

Choice

Correct?

Score

Feedback

Correct answer

keep pace with evolving international standards and processes for trade

0

account for reductions in prevalence of the classical meat safety diseases and use a more risk-based system of inspection

0

move to a more self-regulatory (as opposed to Government-inspected) approach

0

all of the above

0

Answer 336

All of the above

Question 337

The organisation responsible for the Sanitary & Phytosanitary (SPS) Agreement is

Answer 337

World Trade Organisation (WTO)

Question 338

The organisation responsible for setting maximum residue limits in Australia is

Answer 338

Australian Pesticides and Veterinary Medicines Authority (APVMA)

Question 339

Electrical stunning

Lairage

Trimming

Evisceration

Post-mortem carcass inspection

Match these five key stations in a sheep abattoir to the order they occur:

Answer 339

1. Lairage
2. Electrical Stunning
3. Evisceration
4. Post-mortem carcass inspection
5. Trimming

Question 340

What is a weasand? Sticking? Pluck? Bung?

Answer 340

Weasand- oesophagus

Stick- throat cut

Bung- rectum

Pluck- heart and lungs

Question 341

Potential food safety threats originate in six different areas. Here are five; can you remember the other one (from the virtual beef abattoir)?:

1. Microbial contamination
2. General disease
3. Pharmaceuticals
4. Hormones
5. Pesticides and environmental chemicals
6. ____________________________

Answer 341

Foreign materials

Question 342

What are the five freedoms?

Answer 342

1. Freedom from hunger and thirst

In order to decrease the amount of faecal contamination and gut spillage during carcass dressing, animals presented to abattoirs are kept off food prior to slaughter. However, transport hauliers and abattoir management have to be aware of certain species and age-related standards regarding time off feed. For example, bobby calves cannot go longer than 18 hours since their last feed. Water should be available at all times to all species, and animals should be able to drink within an hour of arrival at the abattoir.

2. Freedom from discomfort

3. Freedom from pain, injury and disease

4. Freedom to express normal behaviour

5. Freedom fear and distress

Question 343

The current Industry Animal Welfare Standards for Livestock Processing Establishments relate to six areas. Five are listed here – can you remember the other one?

1. Management procedures and planning
2. Design and maintenance of facilities and equipment
3. ________________________________________________
4. Management and humane destruction of weak, ill or injured livestock
5. Management of livestock to minimise stress and injuries
6. Humane slaughter procedures

Answer 343

Staff competency

Question 344

Correct stunning

Response

Your answer

Choice

Correct?

Score

Feedback

Correct answer

results in animals experiencing no pain on slaughter

0

ensures large livestock are adequately restrained

0

results in better meat quality

0

all of the above

0

Answer 344

All of the above

Question 345

T or F: Head-to-body electrical stunning is not suitable for Halal processing.

Answer 345

True

This statement is true. Head-to-body electrical stunning causes cardiac arrest resulting in death prior to slaughter. According to Halal rules, this is not permitted.

Question 346

There has been controversy about the humaneness of gas stunning (CAS) because __________________ is not instantaneous.

Answer 346

insensibility

Question 347

T or F: Stunning is not used in the slaughter of animals for Halal meat in Australia.

Answer 347

False

Question 348

Restraint devices for slaughter without stunning which involve inverting the animal onto their backs are considered inappropriate by Australian standards because

Response

Your answer

Choice

Correct?

Score

Feedback

Correct answer

activates the sympathetic nervous system

0

delays the onset of unconsciousness following neck incision

0

impairs heart action and impedes blood flow

0

all of the above

0

Answer 348

All of the above

Question 349

There are six areas monitored and used to underpin auditing in the Industry Animal Welfare Standards. These are:

1. Electronic prodder use
2. Vocalisation
3. Correct stun first shot – Cattle
4. Bleed rail – Cattle
5. Tong placement – Pigs
6. _______________________________

Answer 349

Slips and falls

Question 350

Within how many hours before slaughter must ante-mortem inspection be performed?

Answer 350

24 hours

Question 351

Animals that fail ante-mortem inspection and are separated out of the slaughter line include those animals that are (add the missing condition):

1. not healthy
2. affected by a physiological condition
3. still in a withholding period
4. not mobile
5. ________________________________________________

Answer 351

Excessively dirty

Question 352

The Authorised Officer must view all animals on both sides and from the front and rear in these two states:

1. At rest in an undisturbed state
2. ________________________________________________

Answer 352

In motion

Question 353

Animal whose condition is not easily or quickly determined

Animal that is affected by a disease that would respond to treatment

Animal cannot move unassisted

Animal that is excessively soiled

Animal with clinical mastitis

Answer 353

Animal whose condition is not easily or quickly determined- retained for further inspection

Animal that is affected by a disease that would respond to treatment- returned for further treatment

Animal cannot move unassisted- emergency slaughter

Animal that is excessively soiled- rejected from slaughter

Animal with clinical mastitis- restricted slaughter

Question 354

Post-mortem inspection is carried out for four main reasons. Add the missing reason.

1. to ensure the quality and integrity of the product
2. because it is a legal requirement, as mandated by federal and international governing agencies.
3. to protect animal welfare by identifying evidence of in-humane handling (e.g. multiple stunning, bruising)
4. ____________________________________

Answer 354

To protect the health of the consumer

Question 355

In post-mortem inspection, the inspection of the head is not a requirement for export of cattle, as it is with sheep.

Answer 355

This statement is false. Inspection of the head is not a requirement for export of sheep, as it is with cattle.

Question 356

Post-mortem inspection involves five methods. Four are listed below. What is missing?

1. Visual
2. Olfactory (smell)
3. ___________________
4. Incision
5. Sampling and analysis

Answer 356

Palpation

Question 357

It is important to note that animals passed for unconditional slaughter may still have internal pathology that was not detectable on ante-mortem inspection. Such carcasses may require ________________ or even condemnation.

Answer 357

Trimming

Question 358

A carcass that is fit for human consumption, subject to conditions, is

Answer 358

Diverted to retain rail for trimming

Question 359

Johne’s disease

Contagious ecthyma

Acute arthritis

Generalized bruising

Hydatids

Answer 359

Johne’s disease- intestines and mesentery condemned

Contagious ecthyma- affected carcass parts condemned

Acute arthritis- carcass and all parts condemned

Generalized bruising- carcass and all its parts condemned for human consumption (but OK for animal food)

Hydatids- affected organs condemned

Question 360

The typical presentation for a horse with a bony sequestrum is

Answer 360

• Sequestrum- excessive granulation tissue

Question 361

What is the most common neoplasia affecting the equine penis?

Answer 361

SCC

Question 362

A horse that you castrated earlier in the day now has small intestine hanging from the scrotum. Your initial management should be …

Answer 362

Protect it and transport it

Question 363

An 8-year old Arabian mare used for endurance riding presents to you for assessment of the day after a 100 km race. On close examination, you are unable to appreciate an abnormalities of the horse’s gastrointestinal tract. However, the horse is reluctant to move, has firm quadricep muscles on palpation, and is passing dark red urine. Which of the following is the MOST likely diagnosis?

Answer 363

• Exertional rhabdo

Question 364

Answer 364

Palomino

Question 365

An increase in blood lactate concentration in a horse with abdominal pain strongly suggests the presence of devitalised intestine.

Answer 365

• False

Question 367

You are monitoring a 500 kg horse that has been hospitalised for an elective arthroscopy. The horse is receiving only dry feed (hay, chaff/ and grain) and the weather is mild. Approximately, how much water do you expect that this horse should drink daily?

Answer 367

18-37 liters/day

Question 368

You need to sedate a flighty 3-year-old Thoroughbred colt so it will stand still for a series of prepurchase radiographs. You have access to “Dormosedan” which contains detomidine 10mg/ml. You estimate the weight of the colt to be 500 kg. How much “dormosedan” will you give it intravenously?

Answer 368

0.5 mL

Question 369

From the following list, select the 2 (two) clinical signs that might be expected with anterior enteritis (duodeno-jejunitis)?

Answer 369

• AE: Fever and nasogastric reflux

Question 370

A 300 kg pony is to be treated with 2.2 mg/kg of phenylbutazone orally. You have access to green “Butin” paste that contains 200 mg/mL of phenylbutazone. How much “Butin” paste will you administer to this pony?

Question 371

How much chaff and hay would you expect an idle 10 year old gelding weighing 500 kg to eat daily when in hospital for a routine elective procedure?

Answer 371

• 5kg feed

Question 372

Answer 372

Bay

Question 373

Synovial fluid analysis is most useful for evaluating which of the following diseases?

Answer 373

• septic arthritis

Question 374

From the following list, select the two (2) that you would expect to present with sudden onset, severe and unrelenting abdominal pain?

Answer 374

• SI strangulation from pedunculated lipoma, volvulus

Question 375

You are presented with a 15-year old Quarter Horse gelding that has a two-week history of a persistent cough and a bilateral mucopurulent nasal discharge. The horse is housed outdoors 24 hours a day with constant access to a large round bale of hay. There are 3 other horses in his paddock, none of which are affected. On physical examination, temperature and heart rate are normal, respiratory rate is 44 breaths/minute and you notice some mild-moderate abdominal effort on expiration and nostril flare. Plasma biochemistry analysis, a complete blood count and fibrinogen concentration are normal. Of the following, which is the MOST likely diagnosis?

Answer 375

RAO

Question 376

Answer 376

Buckskin

Question 377

The most informative radiographic views of the carpus of a thoroughbred racehorse with mid-carpal joint effusion are:

Answer 377

Skyline

Question 378

What is the main aim of any cruciate ligament repair surgical technique?

A. To return limb to 100% normal function

B. To reduce pain associated with instability

C. To delay progression of DJD by stablising the joint

Answer 378

ANSWER = C. DJD is almost always already present in the stifle at the time of diagnosis as the process of inflammation in the joint starts the cartilage degeneration. All cruciate stabilising surgeries can do is slow down this progression. The joint can never be 100% normal but the pain from an unstable joint and the risk of meniscal tears can be reduced.

Answer A and B incorrect – a joint that has been damaged can never be 100% normal again and although stabilisation of the joint will reduce pain associated with the condition, the main function is long term management to delay the progression of DJD

Question 379

Halstead’s principles

Answer 379

1. [Gentle] tissue handling
2. Meticulous [haemostasis]
3. Preserve [blood] supply
4. Maintain strict [aseptic] technique
5. Minimum [tension] across tissues
6. Accurate [apposition] of tissues
7. Eliminate [dead] space

Question 380

After performing and single enterotomy on the anti-mesenteric border of the jejunum to remove a linear foreign body in a cat, what is the best method of closure of the enterotomy site?

Answer 380

The submucosa has all the collagen and healing potential, so apposition of this layer is most important for primary healing, a continuous pattern allows even tension if performed correctly and tightens at the site during distension. Omentum can be used to augment the enterotomy closure (acts as drainage).

Question 381

What characteristics of the meniscus make it vulnerable to injury when the cruciate ligament is damaged?

Answer 381

The caudal pole of the medial meniscus is most commonly injured when the cranial cruciate ligament is damaged, since it is less mobile due the attachment to the collateral ligament and an unstable joint leads to increased shear force from internal rotation and cranial translation of the tibia.

Question 382

When performing an exploratory laparotomy, the skin incision is made then the subcutaneous tissue is incised to expose the linea alba. In dogs the subcutaneous tissue is connected intimately with the linea alba and exposure can be difficult. What is the best method to use to improve visibility and ensure accurate entry into the abdomen?

Answer 382

Blunt dissection can be performed in a longitudinal and lateral plane to expose the linea alba using metzembaum scissors. If necesaary subcutaneous tissue overlying the linea alba can be carefully resected to improve visualisation.

Correct – this gives the best exposure of the linea alba and improves accuracy for the abdominal incision. Any dead space created can be closed by suturing the subcutaneous layer.

Question 383

During and exploratory laparotomy for a 9 year old dog that had a gastric foreign body, you find a 2cm nodule in the spleen. What is the best course of action?

Answer 383

Perform a complete splenectomy and submit for histopathology

The spleen is highly vascular and has a very thin capsule that makes it almost impossible to suture, therefore haemorrhage is a significant problem, so a complete splenectomy is preferred over biopsy or partial splenectomy.

Answer A is incorrect as cytology often will not give a definitive diagnosis, a tissue sample is preferred

Question 384

lease sequence the following spinal cord function from the first one to disappear (1st) to the last one to disappear (4th) when a dog or a cat has a compressive spinal cord disease?

Urinary/faecal continence [a]

Proprioception [b]

Deep Pain sensation [c]

Voluntary motor function [d]

Answer 384

conscious proprioception is the first clinical sign to change, followed by voluntary motor function, urinary/faecal continence and finally deep pain perception.

Question 385

During an exploratory laparotomy for a linear foreign body in a cat, you find there is an area of perforation at the mesenteric border of the duodenal flexure distally and you decide an intestinal resection and anastomosis is required. What is the best method of exposure at this location?

Answer 385

Transection of the duodenocolic ligament allows easier manipulation and access of this segment, as it acts as an anchor point making exteriorisation difficult.

Question 386

The 5 year old, 30kg German shepherd dog that presented for RHL lameness has thickening (effusion and medial buttress) of the right stifle on palpation. He is very tense in the consultation room and tibial thrust/cranial drawer are both negative. What other physical examination method can be used to assess if stifle pain is present?

Answer 386

Stifle hyperextension often causes significant reaction when stifle pain (and likely cruciate disease) is present. Hyperextension causes tensioning of the gastrocnemius tendon, producing cranial thrust with cranial tibial translation

Question 387

What length of intestine can be resected before complications such as short bowel syndrome, become a problem?

Answer 387

If less than 70% of the intestine is resected long term complications are minimal

Question 388

§5 Yr.o. Female (N) crossbreed

§Vomiting 5 days – haematemesis

§Diarrhoea (recent)

§Anorexia

§Dry mm membranes, CRT = 4s

§Weak pulse, HR = 140 bpm

§Mild abdominal pain

** DDX?

** Diagnostic tests?

Answer 388

Differential Diagnoses?

úDietary indiscretion

úPancreatitis

úIntestinal obstruction

úGastric ulceration

úHepatitis

úPeritonitis

úOther ‘acute abdominal’ crisis?

úHypoadrenocorticism

úDKA

§Which diagnostic test(s) would you do next?

§

úAbdominal radiographs

úAbdominal ultrasound

úAbdominocentesis

§How would you treat the patient?

§

úFluid therapy (0.9% NaCl indicated by electrolytes) plus potassium chloride

úExploratory laparotomy

Question 389

§6 Yr old M(N) Border Collie

§Vomiting & Diarrhoea (intermittent, 6 months)

§

§Anorexia, Lethargy

§Drinking ↑

§

§Pale membranes

§CRT = 3s

§Dehydration (7%)

§HR = 62/min, RR = 15/min

** DDX?

** Most likely?

§What are the strangest findings?

§

úBradycardia in this seriously ill dog (you ‘expect’ tachycardia…)

úEosinophilia in this seriously ill dog (this is not typical of stress)

ú

Answer 389

Anaemia

úDecreased production

úDestruction

úLoss

úSequestration

Low cholesterol

úLiver disease

úDecreased intake

Hypoglycaemia

úArtefact

úInsulin overdose

úInsulin-producing tumour

úAdvanced liver failure

úSepsis

úHypoadrenocorticism

Azotaemia

úRenal

úPre-renal

Hyperproteinaemia

úDehydration

úHyperglobulinaemia

(not in this case)

§

Reduced Na: K ratio

úHypoadrenocorticism

úRenal and urinary tract disease

(low sodium)

úSevere liver disease

úSevere GI disease

Incl. whipworm

úAcidosis

úChronic heart failure

úSevere muscle injury (crush)

** Renal disease and hypoA

§How would you confirm a diagnosis of hypoadrenocorticism?

úACTH stimulation test

** no response to ACTH rejection= hypoA

mmediate

§Intravenous fluid therapy with 0.9% NaCl à restores blood volume and decreases potassium immediately

§Replacement of adrenal steroids

úHydrocortisone or

úDexamethasone or

úDOCP

§Long-term Management

úDOCP (Desoxycorticosterone Pivalate) plus prednisolone/cortate, or

úFludrocortisone plus prednisolone/cortate

Question 390

§7 Yr.o. male Golden Retriever

§Anorexia

§Increased thirst (mild)

§Pale faeces

§

§Relatively bright

§Icterus (= jaundice)

** What causes jaundice?

** DDX?

** What tests should you consider before surgery and why?

Answer 390

1. Pre-hepatic causes

• Haemolysis

2. Hepatic causes

• Injury to hepatocytes
• Hepatitis
• Neoplasia

•

3. Post hepatic causes

• Bile duct obstruction

Post-hepatic disease seems most likely (clinically “well”, AP very high but ALT marginally increased only, and acholic faeces)

§What are the main DDx?

Bile duct cancer

Cholelithiasis

Pancreatic disease (mass, pancreatitis)

Duodenal mass

§How would you investigate further?

Abdominal ultrasound

Abdominal radiology

Exploratory laparotomy

**

What test should you consider BEFORE

surgery? (and why?)

Clotting status !

Bile duct obstruction

à reduced fat absorption

à reduced vitamin K absorption

à reduced clotting factors 2, 7, 9 & 10

Question 391

§14 year old neutered male DSH

§Weight loss

§Possible increase in thirst

§

§BCS 2/9

§Pale mucous membranes

§Tachycardia, cardiac murmur

§Abdominal mass

**DDX?

** Ionized calcium = normal

What are the significant laboratory changes?

§Non-regenerative anaemia

§Neutropenia

§Lymphopenia

§Thrombocytopenia

What do these suggest to you?

úBone marrow disorder (myeloproliferative, neoplastic, toxic, fibrosis, infectious)

úHypersplenism

Answer 391

§Abdominal mass

úNeoplasia, lymph node, intestinal foreign body, organomegaly (spleen), granuloma

§Weight loss with increased appetite

úHyperthyroidism, EPI, malabsorption due to intestinal disease, diabetes mellitus, cardiac cachexia

§Tachycardia, cardiac murmur

úCardiac disease (congenital or acquired-such as hypertrophic cardiomyopathy)

úAnaemia

§Possible polyuria and polydipsia

úRenal insufficiency, hyperthyroidism, diabetes mellitus, hepatic insufficiency, hypercalcaemia

§Pale mucous membranes

úAnaemia

Decreased production

Destruction

Loss

Sequestration

úCardiac disease

§FeLV and FIV negative

§Imaging

úNormal thoracic radiographs

úHepatomegaly, splenopathy, and multiple small nodules (likely lymph nodes) on abdominal ultrasound

Question 392

§3 yo M(N) Siamese

§1 month history of coughing and lethargy

§Acute onset of dyspnoea

§Physical Exam:

úAnxious but responsive

úMM pink & moist, CRT < 1 sec

úHR = PR = 180 bpm

úOpen mouth breathing, RR 50 with increased expiratory effort and expiratory wheezes

úNo abnormalities abdominal or lymph node palpation, T 38.8 deg C

§Problem list

úExpiratory dyspnoea (tachypnoea)

úCoughing (1 month)

úAnxious - acute

úLethargy (1 month)

** What diagnostic test?

Answer 392

§Minimise stress and handling

§Oxygen (oxygen cage > flow by > facemask)

§Get IV access

§? Should you try thoracocentesis NO

§Bronchodilator YES- which one?

úTerbutaline IV or SC

úSalbutamol / albuterol by inhalation

úAminophylline (IM)

úNorepinephrine IV (IM, SC)

§? Furosemide IV

§? Glucocorticoids

Dexamethasone IV (IM, SC)

Prednisolone sodium succinate IV

§?Nitroglycerine topically

What diagnostic tests would you do NEXT?

§Thoracic radiographs

úWhen?

§Blood tests- pick the most useful

úComplete blood count

úBiochemistry

úHW testing

úBlood gas

úFIV/FeLV

úToxoplasma titre

úCoronavirus titres

§Faecal examination + Baermann

§Lung cytology

úHow?

§Echocardiogram

§Laboratory data

§Peripheral eosinophilia

úInflammatory/allergic

úParaneoplastic

úParasitic

úSystemic eosinophilic disease

§What is your interpretation?

§Diffuse bronchial pattern, hyperinflation, flattening and caudal displacement of diaphragm

§What does this suggest?

§Suggests inflammation of airways

§DDx asthma, lymphoma, lungworm, less likely pneumonia, FIP, fungal

§What would you do next?

§On lung cytology > 50% of cells are eosinophils; no aetiological agents are seen

§What other test would you do on this samples? Culture, specify Mycoplasma. This sample was negative

§What are your DDx now?

§Feline bronchial disease

§Heart worm (Dirofilaria immitis)

§Parasites: Aelurostrongylus abstrusus, Capillaria aerophila, Paragonimus spp.

§Fungal disease

§Hypereosinophillic syndrome

§What is the most likely diagnosis? Feline Bronchial Disease

§Acute setting

úOxygen

úMinimise stress / handling

úIV or inhaled bronchodilators

ú+/- IV glucocorticoids

§Chronic setting

úGlucocorticoids – PO, inhaled

úBronchodilators – PO, inhaled

úRx secondary infections

Question 393

§6 year old FN Bichon Frise

§Acute onset of collapse

§PE :

ú Depressed but responsive, unable to stand

ú5/9 BCS

úMM pale pink and moist

úCRT < 1 sec, HR = PR = 180 bpm

úGrade 2/6 left apical systolic cardiac murmur

úRR 40/min

úNormal abdomen, T 37.9˚C

§Collapse (unable to stand)

úMetabolic (↑↓K, ↓glucose)

úHaematological (↑↓ PCV)

úCardiovascular (CHF, arrhythmia)

úRespiratory

úNeuromuscular (CNS, myopathy, myasthenia gravis, IVDD)

úOrthopaedic (bilateral cruciate rupture)

úEndocrine (hypoadrenocorticism, hypothyroidism, pheochromocytoma)

§MM pale- anaemia, high sympathetic tone: reduced cardiac output with poor perfusion

§Grade 2/6 left apical systolic murmur- anaemia (haemic murmur), mitral regurg (endocardiosis, endocarditis, DCM)

§Tachycardia- §Anaemia / hypoxia, CHF, shock, hypotension, sepsis, anxiety / fear, pain, high sympathetic tone, tachyarrhythmia

§Tachypnoea

§Overweight

§Mentally dull

Answer 393

§Severe regenerative anaemia

úRed cell destruction (inc. IMHA, onion or Zn toxicity, microangiopathic haemolytic anaemia, DIC), red cell loss (haemorrhage)

§Spherocytes

úRed cell destruction as above

§Microscopic auto-agglutination

úRed cell auto-antibodies

§Neutrophilia with left shift

úNon specific bone marrow stimulation, infection

§Monocytosis

úStress response, inflammation, immune mediated disease, haemolysis

§Immune mediated haemolytic anaemia

úPrimary – idiopathic

úSecondary – infectious, neoplasia, drug, Zn FB

§What questions do you have for the owners?

úPrior drug history (including vaccines, over the counter and preventative health-care)

úTravel history - ticks

úToxicity ? Including foreign bodies, onions etc

úPrior disease

úPrior transfusions

§Search for an underlying cause

úThoracic radiographs

úAbdominal ultrasound

ú+/- Infectious disease panels (geographically dependant)

E.g. HW, Babesia canis or Gibsoni, Ehrlichia spp., Rickettsia

ú+/- BM – if no response to Rx, for BM disorder

ú+/- PT/APTT (ACT), FDP, fibrinogen, AT III for DIC

§+/- Cross match / blood type

úOnly if has had prior transfusion

§Initial treatment plan for idiopathic (primary) IMHA

úpRBC transfusion (or whole RBC transfusion if not available)

úPrednisolone 1 mg/kg BID PO until normal PCV and and no auto-agglutination or spherocytes, then taper ~ 10-20% every 2-4 weeks while monitoring PCV to lowest effective dose

úAzathioprine 1-2 mg/kg SID PO for 1 week, then EOD, then taper., or start at 1-2 mg/kg eod.

úLow dose aspirin. Why?

úMonitor PCV q 12-24 hr initially

úLong (months) treatment duration

úPrognosis – fair, variable if discharged

Question 394

§8 year old MN DSH

§Pollakiuria 2 days

§Stranguria

§Inappropriate urination, periuria

§Pink urine

§Uncomfortable

§Hyporexia

§Only cat

§No changes in household

§Indoor and outdoor lifestyle

§New cat has moved in next door

§Diet: Whiskas dry, fed ad lib.

§Defecating normally

§Has a single litter tray

§6.7 kg, BCS 7/9

§QAR

§Small and painful urinary bladder

§Otherwise normal

May consider neurological and orthopaedic exams – normal

Small bladder makes obstruction unlikely, as does otherwise normal physical exam.

§Acute onset LUT signs (pollakiuria, stranguria, periuria, pigmenturia, small painful urinary bladder)

§Obesity

§Hyporexia

§Quite

Answer 394

Ultrasound ideal – non invasive, evaluates kidneys and urinary bladder, check for uroliths, mass, wall changes (can’t see entire urethra, usually don’t see ureters).

Bladder wall can look more distended / irregular when small

Normal wall layering is preserved

§After urinalysis and imaging, what is the most likely diagnosis?

§

§Idiopathic FIC (FLUTD)

§Treatment:

úPain relief for 3- 5 days (e.g. buprenorphine) or NSAIDs (ensure eating and hydrated)

ú+/- smooth muscle relaxants (phenoxybenzamine), +/- skeletal muscle relaxants (prazosin / dantrium)

ú+/- anti-anxiety medication (usually if chronic problem), may consider Feliway ®

úGood hydration

§Prevention:

úAddress obesity

úRisk factors in this case for FIC – obesity, new cat next door, dry food diet, only 1 litter tray, fed ad lib.

úReduce stress, resolve inter-cat conflict, weight loss, increase number and cleanliness of litter trays, increase owner interaction / playing, increase water intake

úHill’s c/d

§Prognosis

úUsually resolves in 1 week

ú45% relapse in 6 months, 70% relapse in 1 year

úYet with diet – relapse rates reduced by 89% (1.2 incident days / 1,000 days vs. 11.2 incident days / 1,000 days with controls

Question 395

§5 yo M(N) Samoyed

§4 week history of sneezing and epistaxis (R sided)

§Recently decreased

appetite

§Had grand mal

seizure last night

§P Exam:

úTPR all normal

úSwelling bridge right nose

úBlood tinged R sided

nasal discharge

úNeurological exam

normal

úPainful around head

§Problem list

úSeizure

Intra-cranial (tumour, fungal, bacterial, viral, idiopathic, inflammatory, vascular)

Extra-cranial (metabolic, haematological, toxin)

úR sided nasal bridge swelling

úNasal discharge - R sided epistaxis

úNasal pain

These all indicate a primary nasal disease. Other DDx would be coagulopathy but unilateral

úInappetance

Extension of nasal disease into the brain would be the most logical explanation, but we can’t rule out others just yet

Answer 395

§Blood tests?

úBlood work shows dehdyration and leucocytosis

úLCAT positive > 1: 1024

§Cytology?

úFungal organisms (cryptococcosis) on cytology

§Imaging?

úNasal radiographs

úHead CT scan

úWhy do we need these if we have a diagnosis?

Question 396

Reasons for hypotension in anaesthesia?

Answer 396

* Meds,hypovolaemia, underlying disease, hypoT, cuff size

Check patient, turn iso down, fluid bolus

Question 397

Reasons for hypertension?

Answer 397

* pain, drugs, stress, underlying disease, fluid overload, cuff size, too light anaesthetic, renal disease, hyperA

* check patient, increase iso, increase propofol or increase methadone

Question 398

What would you consider as a low SPO2. Reasons for low SPO2- what actions can you take to get it back up to acceptable levels?

Answer 398

* Lung disease

* FB in the tube- mucus plug– you can often hear it (sound of bag)- cat flu, Bordatella bronchiseptica, suction tube

* Check patient, CRT, reposition, check tubing- make sure not breath holding- give breath, tube in oesophogus? Pre-oxygenate, increase oxygen, not reading properly, decrease iso/ reverse drugs

Question 399

What sort of drug is ACP, what does it do? How logn does ACP last? What are the side effects? Contraindications?

Answer 399

Phenothiazine- alpha 1 adreno receptor antagonist

6-8 hours

Hypotension, vasodilation, splenomegaly

Contraindication: CV disease, hypothermia (2C decrease in temp), avoid in epileptics, mild anti-emetic, avoid in Boxers, HUskies, C-section as it crosses the placental barrier

Question 400

What sort of drug is methadone? What does it do to our patients? How long does Methadone last and what are the side effects?

Answer 400

Opioid mu receptor

4-5 hours

Sedation, bradycardia, nausea, salivation (Cerenia)

* Reversal: Nalaxone, Butorphanol

Question 401

What sort of drug is Atropine? What are its effects? How long does it last and what are the side effects?

Answer 401

Anticholinergic, 10-15 minutes, Tachycardia, increase in BP, Decrease in gastric motility, increase chance or regurg, side effects: anti- SLUD

* Use more eye lube

Question 402

What sort of drug is dexemeditomidine? How long does dexemeditomidine last? What are the effects and side effects?

Answer 402

Alpha 2 agonist, reflex bradycardia, kittens–> faster, CARE asphyxiation, 45 minutes, Atipamezole

Question 403

What MAP is considered as hypotensive? What would you do if your patient is hypotensive?

Answer 403

< 60 mmHg, ephedrine 0.1 mL/kg, decrease iso, give fluid (bolus first)

Question 404

How can you tell if your patient is too light?

Answer 404

Palpebral reflex, jaw tone, central eye position, increase HR, increase BP, increased RR

Question 405

How can you tell if your patient is at surgical depth?

Answer 405

Eye position (medial), stable vitals, jaw and palpebral reflex

Question 406

How can you tlel if your patient is too deep?

Answer 406

Bradycardia- dilated pupils, dry eyes, RR decrease, eye position- centrla, decrease in vitals

Question 407

What do you do if your patient is too light?

Answer 407

Increase iso, give some breaths, top up on propofol, 3-5 minutes quicker with non-rebreathing

Question 408

What do you do if your patient is too deep?

Answer 408

* Decrease iso, give reversal

Question 409

How many fluid boluses can you deliver in the first hour of surgery

Answer 409

3

Question 410

Why would you get pale MMs?

Answer 410

Decrease in perfusion, vasoconstriction, blood loss, anaemia

Question 411

Answer 411

B. Call the exotic disease hotline

Question 412

Answer 412

D. Insufficient chilling of the bulk vat- epithelial and inflammatory cells- not bacterial cells (BMCC)– somatic cells

Question 413

Answer 413

Oxytocin (IM)- may want it for heifers after first calving

Question 414

Answer 414

True

Under the Prevention of Cruelty Act 1986– 24D- you have the authority

under 24A POCTA inspector can decide to destroy an animal if not on the person’s dwelling

Question 416

Answer 416

A. Administer an epidural injection of lignocaine.

B. don’t do!! vasodilation, hot water, wash with room temperature water

C. Frog leg position

D. Face the animal slightly down hill

Question 417

Answer 417

D.

Stab those cows with breathing difficulties in the left flank

with a knife (do simultaneously with A)

A.

Get the herd out of the paddock. (would be highest priority if you don’t have help)

B.

Administer bloat oil to the cows with a drench gun

C.

Call the knackery to remove the dead stock

Question 418

Answer 418

Eimeria zuernii- Coccidiosis

Mycobacterium paratuberculosis- JD

Streptococcus uberis- Mastitis

Clostridium hemolyticum- bacillary haemoglobinuria

Question 419

Answer 419

B. 6 weeks of age (rumen development)

Question 420

Answer 420

Meloxicam- anti-inflammatory

Trimedexil- LA Corticosteroid- induction of parturition

Cloxacillin- injectable treatment of mastitis

Engemycin (Oxytet)- broad spectrum injectable antibiotic

Question 421

Answer 421

D. Horses

Question 422

Answer 422

Question 423

Answer 423

Question 424

Answer 424

Question 425

Answer 425

Question 426

Answer 426

Question 427

Answer 427

Question 428

Answer 428

Question 429

Answer 429

Question 430

Answer 430

Question 431

Answer 431

Question 432

Answer 432

Question 433

Answer 433

Question 434

Answer 434

Question 435

Answer 435

Question 436

Answer 436

Question 437

Answer 437

Question 438

Answer 438

Question 439

Answer 439

Question 440

Answer 440

Question 441

Answer 441

Question 442

Answer 442

Question 443

Answer 443

Question 444

Answer 444

Question 445

Answer 445

Question 446

Answer 446

Question 447

Answer 447

Question 448

Answer 448

Question 449

Answer 449

Question 450

Answer 450

Question 451

Answer 451

Question 452

Which set of results is consistent with upper intestinal obstruction?

a) Dog A
b) Dog B
c) Dog C
d) Dog D

Answer 452

Question 453

Which set of results is consistent with diabetes ketoacidosis?

a) Dog A
b) Dog B
c) Dog C
d) Dog D

Answer 453

Question 454

Answer 454

Question 455

Answer 455

Question 456

Answer 456

Question 457

Answer 457

Question 458

Answer 458

Question 459

Answer 459

Question 460

Answer 460

Question 461

Answer 461

Question 462

Answer 462

Question 463

Answer 463

Question 464

Answer 464

Question 465

Answer 465

Question 466

Answer 466

Question 467

Answer 467

Question 468

Answer 468

Question 469

Answer 469

Question 470

Answer 470

Question 471

Answer 471

Question 472

Answer 472

Question 473

Answer 473

Question 474

Answer 474

Question 475

Answer 475

Question 476

Answer 476

Question 477

Answer 477

Question 478

Answer 478

Question 479

Answer 479

Question 480

Answer 480

Question 481

Answer 481

Question 482

Answer 482

Question 483

Answer 483

Question 484

Answer 484

Question 485

Answer 485

Question 486

Answer 486

Question 487

Answer 487

A. The ewe is grazing improved pasture of 500 kg dry matter/ha availability– she would be on 1000 kg dry matter/ha (twin bearing 1200)

Question 488

Answer 488

C. All affected cattle should be given a course of IM injections of penicillin registered for use in cattle.

Question 489

Answer 489

C. Hyperthyroidism and renal insufficiency can be excluded

Question 490

A ten year old German Shepherd from suburban Melbourne presents with progressive abdominal distension over a period of days, and recent onset of dyspnoea. The herat and lung sounds are muffled on physical exam, and fluid obtained on abdominocentesis was classified as a modified transudate. What is the most likely diagnosis?

a) Pulmonic stenosis
b) Heartworm disease
c) Pericardial effusion
d) Tricuspid valve dysplasia

Answer 490

d) Tricuspid valve dysplasia

Question 491

Which set of results is consistent with hypoadrenocorticism?

a) Dog A
b) Dog B
c) Dog C
d) Dog D

Answer 491

d) Dog D

Question 492

Answer 492

B. Mineralisation within the parenchyma

Question 493

Answer 493

D) Diabetic ketoacidosis

Question 494

Answer 494

B) Collapsing trachea

Question 495

Answer 495

B. ulna carpal bone

Question 496

Anaemia of iron deficiency characterisation

Answer 496

microcytic, hypochromic, potentially severe anaemia with a variable regenerative response

Question 497

Anaemia of chronic disease characterization

Answer 497

Mild to moderate, nonregenerative, normochromic and normocytic

* secondary to chronic inflammation or infection, neoplasia, liver disease, hyperA or hypoA, hypothyroidism

Question 498

Anaemia of onion poisoning characterisation

Answer 498

Heinz bodies and eccentrocytes

Strong regenerative response, macrocytosis, aniscocytosis, hypochromasia

Question 499

IMHA anaemia characterisation

Answer 499

Moderate to marked regenerative response, macrocytic, hypochromic

Question 500

HACCP CCPs and CLs

Answer 500

CCPs (Critical Control Point)/ Critical Limits (CLs)

Milk pasteurization

Down to 5C within 24 hours or at 60C or hotter when it is received, displayed, transported or stored

Nitrite (prevents C. botulinum)

Meat cooked at 65C for 10 minutes

Metal detector

Question 501

Salmonella typhimurium PPE

Answer 501

Gloves, closed toed shoes, lab coat, face and eye protection

Question 502

Most important sample for histopathology confirmation of Bovine Johne’s Disease

Answer 502

Tested intwo stages:

1. Screening test of a large sample of mature animals from the herd- HT J PCR or ELISA
2. Test of animals that showed a reaction to the bacteria Follow up faecal culture or tissue culture and histopathological investigation of any reactors—histology- high specificity and sensitivity but requires animal slaughter and immediate collection of samples

Question 503

Staging of Lymphoma

Answer 503

Stage I: Involvement of a single Lymph Nodes (or lymphoid tissue in a single organ) only

Stage II: Regional involvement of multiple LNs (either in front half or back half of the body)

Stage III: Generalized lymph node enlargement (this typically refers to enlargement of lymph nodes in BOTH the front and back half of the body)

Stage IV: Involvement of the liver and/or spleen

Stage V: Involvement of blood, bone marrow, central nervous system, or other organs

** Usually diagnosed in Stage III

Substage a: Where there are no systemic signs of disease (i.e. the patient generally seems healthy and symptom free)

Substage b: Where there ARE systemic signs of disease (i.e. the patient demonstrates general symptoms of not feeling well)

** substages consistent predictor of whether or not a dog will go into remission

** Staging tests (ALL):

• chest rads
• abdo U/S
• full blood panel
• bone marrow aspirate
• urinalysis

Question 504

Appropriate conservative treatment of IVDD with mild pain (how long to rest, appropriate analgesia)

Answer 504

For both disk extrusions and protrusions– strict cage rest 4 to 6 weeks duration (two to three walks 5-10 minutes on leash are allowed– but harness if cervical)– followed by 4 to 6 weeks of progressive exercise re-introduction

* Pain relief:

* Tramadol 2 to 10 mg/kg at least three times a day

* Gabapentin 10 to 20 mg/kg 3 times per day

* NSAIDs for a few days

** Tramadol and Gabapentin first and add some NSAIDs if necessary

** Corticosteroids are C/I as they have increased morbidity (risk of GI disorders by 3 and risk of UTI by 5 without any benefit)

Question 505

Urinary incontinence for a UMN bladder

Answer 505

Phenoxybenzamine hydrochloride (alpha adrenergic antagonist) relaxed internal urethral sphincter

Diazepam- relaxes the striated fibres of the external urethral sphincter

Question 506

Urinary incontinence LMN bladder

Answer 506

* Bethanechol- parasympathomimetic drug facilitates the detrusor contraction

Question 507

Yorkie with tetraparesis, reduced reflexes, positive pain, diminished blink/menace– next step?

Answer 507

Idiopathic Cerebellitis/ Shaker Dog Disease/ White hair shaker syndrome

* Maltese, West highland white terriers, Bichon frise, spitz, samoyed, beagle, dachshund, yorkies, spring spaniels

Clinical signs: tremors in all four limbs and head, absent menace response, nystagmus, head tilt, tetraparesis, paraparesis, +/- hypermetria and body swaying, rarely seizures

**UNK pathogenesis– acquired autoimmune disorder affecting neurotransmitter synthesis (dopamine, epinephrine, and norepinephrine) has been hypothesized

* Immunosuppressive doses of CS e.g. prednisolone at 1-2 mg/kg PO BID until clinical remission followed by the lowest dose that controls the signs

Concurrent administration of Diazepam 0.5 mg/kg TID for 4 weeks speeds resolution of clinical signs

Question 508

Clinically healthy dog with low thyroid but negative for auto-antibodies– euthyroid sick syndrome, hypothalamic problem, auto-immune or early atrophy

Answer 508

TT4- if normal- dog probably doesn’t have hypoT, if low could be hypoT

Free T4 (equilibrium dialysis)- low

TSH- high

BUT still could be euthyroid sick

* if unsure and want to know.. U/S, scintigraphy, TSH, thyroid biopsy, treatment trial

** circulating antithyroglobulin antibodies can detected in as many as half of dogs with hypoT– autoimmune thyroiditis

* Certain breeds have lower T4– Grehounds, sight hounds, Alaskan Sled Dogs (intense racing or training)

*euthyroid sick syndrome- any illness can affect thyroid function tests (or drugs- GCs, phenobarbital, sulfonamides, clomipramine and aspirin)

Question 509

Calculate how many mLs of 50% dextrose would you add to 1L bag of LRS to make a 2.5% solution. What is the resultant osmolality?

Hint: to convert % to mg/mL, move the decimal point one place to the right e.g. 50% dextrose = 500 mg/mL, 2.5% dextrose = 25 mg/mL

Answer 509

goal is 25 mg/mL…..25,000 mg dextrose in 1000 mL (or 1 L)

Since 50% is 500 mg/mL, 25,000/500 = 50 mL– you need to remove 50 mL first

* Osmolarity of 50% dextrose is 2780 mOsm/L, so 2.78 mOsm/mL. Since you are starting with a bag of Hartman’s which has 272 mOsm in it, you took out 50 mLs you are left with a bag with 258 mOsm in it (272- (50*0.272))= 258 mOsm. Then you add back in 139 mOsm from dextrose [2.78 mOsm/mL x 50 mL= 139 mOsm], so 258+139=397 mOsm.

Question 510

Which product is combined heartworm and intestinal wormer? Interceptor spectrum, HeartGuard Plus, Revolution, Comfortis

Answer 510

HeartGuard Plus

Question 511

What do you give a cow with grass tetany?

Answer 511

4 in 1– mainly magnesium but also calcium as often hypocalcaemia coincides

Question 512

Daily fluid requirement for maintenance?

Answer 512

Question 513

Treatment of a cow with Ketosis

Answer 513

Oral dextrose or oral propylene glycol or IV glucose

Question 514

Most important step in managing a goat herd with CAEV detected in several age cohort mobs

Answer 514

Snatch rearing/ dirty mob/clean mob

Question 515

Ferret with hyperkeratotic lesions on footpads likely Disease?

Pyoderma, bumblefoot, sarcoptic mange, trixacara mange– unlikely any of these

Answer 515

Canine distemper virus (and nasal planum= pathognomonic)

Question 516

Two most important blood parameters for kidney health in a bird

Answer 516

Uric acid– consider with clinical signs, protein level, PCV and water intake

Question 517

Which disease less likely to transfer from wild birds to domestic fowl? Mycobacterium avium, Salmonella, Yersinia, Mycoplasma

Answer 517

Mycoplasma

Question 518

Optimal analgesia for a spay perfomed by an inexperienced surgeon

* Bupivicaine v. Lignocaine

* Meloxicam v. Carprofen

* Buprenorphine v. Methadone

Answer 518

* Bupivacaine v. Lignocaine

• Bupivacaine longer duration (up to 8 hours when combined with epinephrine) but more cardiotoxic, lower toxic dose
• Lidocaine duration of action dependent on uptake but around 1 hour, 2 hours with epinephrine– may cause some local irritation and swelling which is esp a problem in a horse

* Meloxicam v. Carprofen (Rimadyl)

• Meloxicam: 12-24 hours (up to), onset of effect 1 hour
• wash out period of 5-7 days before starting a new NSAID– LONG half life in dogs
• Carprofen longer onset of action– absorbed faster when administered orally vs. subcut.
• 18-24 hours after sub cut in cats
• Rimadyl (Carprofen) accepted as safer??

* Buprenorphine v. Methadone

• Bup- partial mu opioid agonist (high affinity for mu receptor but only partial activity therefore moderate analgesia and variable sedation), s/e bradycaria, respiratory depression, etc., slow onset of action (30-40 minutes) and a long duration of action (6-12 hours), especially effective in cats– considered safe in cats with HCM
• Methadone- pure mu opioid agonist, s/e dysphoria, nausea, reduced GIT motility, respiratory depression, and bradycardia, short onset of action (lipid soluble and cross the brain barrier quickly), provides 4-6 hours of analgesia + binds to the NMDA receptor in the CNS where it works as an antagonist which prevents central sensitisation and wind up, two phenomena involved in the development of chronic and neuropathic pain

Question 519

Optimal anaethesia for a seizure patient having an MRI- butorphanol v. methadone, propofol TIVA v. isoflurane, spontaneous v. mechanical ventilation

Answer 519

* butorphanol v. methadone

• methadone: mu receptor agonist, non-competitive inhibitor of NMDA receptors, reduces reuptake of norepinephrine and serotonin which may contribute to its analgesic effects, C/i CHF, hypertension, head injuries, elevated CSF pressures, and geriatric or severely debilitated patients– can reverse Methadone… 4-6 hours for analgesia
• butorphanol: partial opiate agonist/antagonist, C/i liver disease, hypothyroidism or renal insufficiency, Addison’s , head trauma, increased CSF pressure or other CNS dysfunction (e.g. coma), geriatric or severely debilitated patients… sedation 2-4 hours; analgesia < 1 hour

*propofol TIVA v. isoflurane

*spontaneous v. mechanical ventilation

• mechanical ventilation would be better than spontaneous in this situation in order to control CO2 levels

Question 520

Spironolactone

Answer 520

Aldosterone antagonist used as a potassium sparing diuretic or for adjunctive treatment for heart failure (controversial in dogs)– should not be substituted for Furosemide in CHF

C/I Addison’s, Hyperkalaemia, anuria, acute renal failure, renal impairment

** Used in patients not responding to Furosemide and ACE inhibitors, who develop hypokalaemia on other diuretics and are unwilling or unable to supplement with exogenous potassium sources

Question 521

Best test to diagnose hyperA? Best test to monitor hyperA?

Answer 521

Best test to diagnose hyperA?

Best test to monitor hyperA?

Question 522

Interpret test results for monitoring trilostane therapy and advise next management step

Answer 522

Trilostane can treat both PDH and AT. However when no signs of metastasis, surgery is the prefered treatment for AT. Trilostane may control clinical signs, but is not associated with reduction in size of tumour.

When treating a larger dog, mitotane treatment may be preferred for economic reasons.

* Similar survival times, but less side effects apparently with Trilostane

* Do not use in animals with hepatopathy or pre-existing renal disease

s/e v+ & d+, hyperkalaemia, hypoA, adrenal necrosis (sudden death or hypoA)

*Taken with food– controls signs of HAC 67-100% of cases within 3-6 months

* Trilostane is a synthetic steroid which competitively and reversibly inhibits the action of an enyme essential to the production of steroid hormones. Peak serum concentration in dogs seen in 1.5; at 18 hours the drug has been completely metabolized.

** Monitor– ACTH stim test 6 monthly

• monitoring at 10 days, 1 month, then every 3 months for signs of hypocortisolaemia (addison’s) are observed or the dose is adjusted. Blood samples should be obtained 2-6 hours after the trilostane is given.

(Trilostane changes the appearance of the adrenals on U/S, they increase in size and become more heterogenous, thus they may be mistaken for adrenal tumours).

Question 523

Maintenance fluids for a 300kg pony

Answer 523

Foals: 80-100 mL/kg/day

Adults: 40-60 mL/kg/day

15 L/day * middle of the range 50*300

Question 524

The most life threatening electrolyte imbalance in a dog with GDV?

Answer 524

Many dogs have normal K+ levels on admission but within 24 hours hypokalaemia occurs. Often compounded by the administration of IV crystalloid solutions deficient in potassium ions. Potassium supplementation is sometimes warranted.

Question 525

Which fracture force are intramedullary pins best at resting?

Answer 525

Effective at resisting bending forces. Easily overcome by axial (compression/distraction) and rotation forces unless the fracture configuration allows an interlock between the major fragments

Question 526

Which physical test is useul to assess hip dysplasia?

Answer 526

Ortolani sign

* Laxity is the primary abnormality in juvenile hip dysplasia

* Mediolateral translation of the proximal femur relative to osseous portions of the pelvis- positive Ortolani sign

* Assessment of pain during forced extension

Question 527

If you move 2 m away from the x-ray machine, what is the percent reduction in radiation dose?

Answer 527

Energy of the scatter radiation will decrease as distance from the radiation source increases according to the inverse square

25%?

Question 528

RG rule for assessing the size of pulmonary vessels in relation to ribs?

Answer 528

Question 529

Elbow dysplasia– four parts? treatment?

Answer 529

* Ununited anconeal process (UAP)

* Fragmentation of the medial coronoid process (FMCP or FCP)

* Osteochrondritis dissecans of the medial humeral condyle (OCD)

* Elbow incongruity

** Evolution of treatments:

• Lag screw fixation, ulnar osteotomy, then fixation + osteotomy + IM pin

Question 530

Answer 530

Question 531

Elbow dysplasia

Answer 531

Question 532

What are the radiographic signs for free peritoneal gas? Which projections?

Answer 532

There are a few different signs to look for when you suspect free peritoneal gas. Serosal surfaces, especially ones that you would not normally see (liver lobes) become visible from the high contrast between gas and soft tissue. You will also see gas that is not contained within the gastrointestinal tract. These gas bubbles often have odd, angular shapes. Gas also tends to rise to the highest point in the abdomen, which is under the diaphragm in both projections. Look for the diaphragm to be outlined by gas on both sides. It is usually highlighted by gas (lungs) on the cranial side, but the caudal side should have stomach wall or liver adjacent to it. When outlined on both sides by gas, the diaphragm will appear as a very thin, sharp, soft tissue line.

The major diagnostic differentials for the distended abdomen in this dog were gastric dilatation–volvulus, hemoabdomen, a ruptured gastrointestinal tract causing pneumoperitoneum, uroperitoneum, and ascites due to right-sided heart failure, hepatic failure, or protein-losing nephropathy/enteropathy.

Pneumoperitoneum can generally be diagnosed on lateral and dorsoventral radiographs if there is a substantial amount of gas present, as in this case. Right lateral recumbency is not recommended because gas bubbles will rise to the left side and may be confused with gas in the gastric fundus.

Question 533

Horse gets a penetrating FB going vertically up through its mid frog, which structure is unlikely to be involved (pedal bone, navicular bursa, DDFT, SDFT)?

Answer 533

SDFT inserts much higher up

Question 534

Which opioid is a partial mu agonist?

Answer 534

Buprenorphine

Routine pain assessment will be integral to successful use of buprenorphine in the clinical setting. Buprenorphine has a delayed onset of action, and analgesic effects may take 30 to 45 minutes following intravenous or intramuscular injection. The authors also point out that duration of action may be shorter than previously thought and repeated dosing may be required. For this reason, cats should be consistently re-evaluated for pain following buprenorphine administration. Whenever possible, intravenous is the preferred route of administration (0.02 mg/kg), as it will have the fastest speed of onset and superior duration of action compared with other routes. Buccal buprenorphine should be reserved for cats that have received premedication with a full mu agonist such as morphine, methadone, or fentanyl. A multimodal analgesic plan that includes a nonsteroidal anti-inflammatory agent or loco-regional anesthesia should be considered whenever possible.

Question 535

kVp and mAs settings best suited…. minimizing exposure time, contrast v. latitude…

Answer 535

mA- milliamperage second - amount of x-rays that will be produced at the target area. Overall exposure (blackness) is controlled by mAs

kVp- kilovoltage peak max value of the applied x-ray tube voltage during x-ray production

** Many shades are gray are produced when using high kVp and low mAs – abdomen and lung

** Increasing kVp increases the number of photons produced and the penetration of the x-ray beam– may cause image to be over-exposed– too black

Preferred Relative Exposures:
• Skeletal – High mAs with low kVp
• Abdomen – Medium mAs with medium
kVp
• Thorax – Low mAs with high kVp

Question 536

Best empirical antibiotic choice for pyothorax prior to C&S results coming back (I think it was pyothorax; may have been peritonitis)

Answer 536

In a study of bacteria isolated from pleural fluid from 51 dogs, obligate anaerobes were isolated from 60 per cent of samples, and a mixture of obligate anaerobes and facultative anaerobes from 44 per cent (Walker and others 2000). The most common anaerobes isolated were Peptostreptococcus anaerobius, Bacteroides species and Fusobacterium species, and aerobes isolated were Actinomyces species, Pasteurella species, Escherichia coli and Streptococcus canis. Therefore, empirical antibiotics chosen for canine pyothorax should have activity against anaerobic and facultative bacteria, be distributed into the pleural space and have low toxicity. Walker and others (2000), recommend the beta lactams ceftizoxime, clindamycin and metronidazole. Cytological and histopathological descriptions of pleural samples often report ‘filamentous …

** if it was empirical AM tx of septic peritonitis– beta lactam (e.g. ampicillin) combined with an aminoglycoside or a fluoroquinolone.

Question 537

Best insecticide to use for acute treatment of flystrike in sheep?

Answer 537

Flystrike dressings contain one of a range of chemicals: diazinon, propetamphos and chlorfenvinphos (OPs), cyromazine (IGR), ivermectin (ML), and spinosad (spinosyn). OPs are generally not recommended because of extensive resistance in flies to this group. The IGRs will help to prevent re-strike while the wound heals but will not kill any third instar larvae until they attempt to pupate.

Prevention relies mainly on reducing the susceptibility of the sheep, using a range of breeding, surgical, husbandry and chemical measures.
 Mulesing is being used less and less as animal welfare pressures accumulate.
 The major chemical preventives are the fly-specific IGRs cyromazine and dicyclanil, mostly used as long-wool products.

Question 538

Which parasite-control agent has the narrowest safety margin? (think this was an easy one, as there was an OP listed alongside various better ones)

Answer 538

**Can’t find safety index for OPs– but sounds like Levamisole is worst… OPs and Slicylanilides are bad too, may be tied… OPs for fish SI- 1.7 then they would be worse

Salicylanilides

sheep: drug of choice for Haemonchus
resistance limited but spreading
dogs: effective against hookworms
but rarely used

Imidazothiazoles- Levamisole

Activity:
• broad spectrum
• all GINs & lungworms
• NOT effective against inhibited larvae and flatworms
• Immunomodulatory effect at lower doses (2-3mg/kg)

Question 539

Legalities in Australia for electric collars for training, debarking, tail docking, ear cropping?

Answer 539

Tail docking & ear cropping: In 2004, tail docking for non-therapeutic reasons was banned across Australia. Since then it has been illegal to dock dogs’ tails unless there is a veterinary medical reason for the operation.Aug 23, 2014

Debarking: Owners of dogs who are debarked in NSW or Victoria must show an official council order identifying the dog as a nuisance barker, and sign a statutory declaration. Victoria goes further in requiring the vet to notify the Bureau of Animal Welfare within seven days of each procedure.

Question 540

Haematuria in a cat DDX

Answer 540

* FLUTD

* Idiopathic cystitis

* UTI–Infections e.g. Leptospirosis

* Neoplasia

* metabolic disorders (e.g. chronic renal disease where uremia results in cystitis

* renal disease

Question 541

Kitten with ocular discharge, salivation, cough, etc… most likely causative agent (herpes vs calici vs chlamydia vs mycoplasma)

Answer 541

Feline Upper Respiratory Tract Infection

* FHV-1 is more virulent than most calicivirus strains but less common.

Question 542

how often does a bitch come into heat?

Answer 542

How often does a female dog come into heat?

Most dogs come into heat twice per year, or about every six months, although the interval can vary between breeds, and from dog to dog. Small breed dogs may cycle three times per year, while giant breed dogs may only cycle once every 12-18 months. When young dogs first begin to cycle, it is normal for their cycles to be somewhat irregular. It can take up to 2 years for a female dog to develop regular cycles. There is no season of the year which corresponds to a breeding season for domesticated dogs.

Question 543

Someone wants to inject their stallion with testosterone to enhance breeding performance – what’s the best reason not to? (in terms of the animal; wasn’t about the legalities or anything)

Answer 543

* used to improve stallion libido– too much results in a negative feedback on the hypothalamus and pituitary, reducing gonadotrophins (LH and FSH) release and hence stimulation of the testis including sperm production.

Question 544

Young German Shepherd with softserve-style diarrhoea and weight loss, but otherwise normal

Answer 544

IBD (or EPI)

Question 545

Best surgical treatment for an otitis externa dog with completely stenotic horizontal ear canals and no response to medical treatment?

Answer 545

Potential complications
–Facial nerve damage
–Haemorrhage
–Can have some hearing after surgery
–Fistulation if tissue left in situ

Question 546

Which PCV/TS combination has the worst prognosis for a horse with sanguinous diarrhoea?

Answer 546

PCV normal 32-52%

TP 4.6 - 6.9 g/dL (46-49 g/L)

* Sanguinous diarrhoea- may be frank blood

Clostridium perfringens ENTEROCOLITIS IN FOALS AND COLOTYPHLITIS IN ADULTS - a spore forming, gram-positive rod that is an obligate anaerobe Diagnosis: Usually made on the basis of Clostridium perfringens isolation (moderate to large growth), identification of the toxic gene (this would be great to have available in Australia) and of course, clinical signs of enterocolitis in foals and colitis/colotyphlitis in adults – remember that diarrhea can be sanguinous but does not have to be

Question 547

Normal PCV in a dog or cat?

Normal TP in a dog or cat?

Answer 547

PCV 35-45%

TP 6.5-80 g/dL (65-80 g/L)

* Elevated TP: dehydration, less common- chronic inflammation, neoplasia, infectious disease (e.g. FIP), multiple myeloma

* Lower TP: haemorrhage, malabsorption, liver disease (e.g. lack of production of albumin), GI disease (e.g. protein losing enteropathy), or kidney disease (e.g. protein losing nephropathy)

Question 548

What are the two things fluorescein is useful for in an opthalmic exam?

Answer 548

Damage to the cornea or FB, patency of the nasolacrimal duct

Question 549

Why is atropine useful in managing uveitis in a cat?

Answer 549

mydriatic (atrophine or tropicamide)– prevents development of posterior synechiae and to provide analgesia via cycloplegia (paralysis of the ciliary muscle)

* Dilation of the pupil should be maintained until clinical improvement of uveitis is observed (1-3 x per day)

* Prolonged pupillary dilation is not of concern as long as the IOP remains below 25 mmHg

* Tropicamide can also be used but requires frequent administration (6-8 hours) duration is not as long as atropine

Question 550

Causes of feline uveitis

Answer 550

Question 551

What Triadan number is a cat’s left maxillary 4th premolar?

Answer 551

There isn’t one??

Question 552

What Triadan number is a dog’s left maxillary 4th premolar?

Answer 552

Question 553

What Triadan number is a horse’s left maxillary 4th premolar?

Answer 553

Question 554

Is ethylene glycol a hepatotoxin in dogs?

Answer 554

No… renal toxin

Clinical signs are dose- and time-dependent and can be divided into those caused by unmetabolized EG and those caused by its toxic metabolites. The onset of clinical signs is almost immediate and resembles alcohol (ethanol) intoxication. Dogs and cats exhibit vomiting due to GI irritation, polydipsia and polyuria, and neurologic signs (CNS depression, stupor, ataxia, knuckling, decreased withdrawal and righting reflexes). Polydipsia occurs due to osmotic stimulation of the thirst center, and polyuria occurs due to an osmotic diuresis and decreased production and release of antidiuretic hormone. As CNS depression increases in severity, dogs and cats drink less; however, the osmotic diuresis continues and results in dehydration. Dogs may appear to transiently recover from these CNS signs ~12 hr after ingestion.

Oliguric acute renal failure usually develops between 12 and 24 hr in cats and between 36 and 72 hr in dogs. Signs include lethargy, anorexia, dehydration, vomiting, diarrhea, oral ulcers, salivation, tachypnea, and possibly seizures or coma. The kidneys are often swollen and painful on abdominal palpation.

Question 555

Poor growth and some diarrhoea in a mob of weaners: best first step in diagnosing/managing?

Answer 555

*DDX: high worm counts or heavy larval challenge

* Diagnosis: WECs (+/- oocysts), faecal smears and culture, post mortem (ileum, caecum, colon): TWC, gut smears and culture, histo, response to treatment

Weaner enteritis: often mixed aetiology: sub-optimal management, nematodes, undernutrition, Se/Vitamin E deficiency, M. ovis

Question 556

Moraxella diagnosed in several sheep in a mob: best mangement step?

Answer 556

*often secondary in small ruminants

* Spontaneous recovery without treatment in 2-3 weeks

* LA oxytet parenterally or injected subconjunctivally– not cloxacillin for sheep

Question 557

What do you do if you suspect an exotic disease at an abattoir? Stun to stick interval?

Answer 557

Chief Veterinary Officer, Department of Agriculture and Water Resources (National), Agriculture VIctoria

Stun-to-stick intervals

The stun-to-stick interval is the time from application of stunning equipment to the start of bleeding. A maximum stun-to-stick interval of 15 seconds is recommended for all species in the field. In the abattoir, all pigs, sheep and goats should also be stuck within 15 seconds. However, on the majority of cattle lines, where the carcase must be hoisted to a bleed area, maximum stun-to-stick intervals of 60 seconds for the penetrative captive-bolt and 30 seconds for the non-penetrative captive-bolt are acceptable. It is essential that equipment is well maintained and that stunning is carried out accurately, using the correct cartridge, to ensure that animals are effectively and irreversibly stunned.

Question 558

Diagnosis of PPID?

Answer 558

Endogenous ACTH assay– preferred screening test, single blood sample, seasonal variation (autumnal hyperactivity)

Other possibilities:

* Dex suppression test

Oral (in feed) glucose tolerance test

Fasting plasma insulin concentration (> 20 micoU/mL suggests EMS)

Question 559

Appropriate next step for a grade 3 vaginal laceration in a broodmare?

Answer 559

Third Degree = complete perforation of the vaginal wall and rectum producing a single opening to the rectum and vagina

(First Degree

Vulval lacerations should be repaired immediately.

Second Degree

The wound should be surgically repaired after the formation of granulation tissue.)

Third Degree

Treatment of third degree perineal laceration is always surgical and the aim is to restore normal anatomy. If the foaling injury is less than 3 hours old, immediate repair can be considered but is rarely performed. There is usually extensive bruising and laceration therefore repair should be delayed until bruising has subsided and granulation tissue has formed, usually a minimum of 6–8 weeks after foaling.

Preparation for surgery:

A laxative diet should be fed. The horse should be placed in stocks and sedated and restrained appropriately. The tail should be wrapped and tied, an epidural administered and the rectum emptied and packed to prevent contamination. The area should be clipped and scrubbed and dorsolateral and ventrolateral retention sutures placed.

There are two techniques for repair of a third degree perineal laceration:

The Aanes technique is a two-stage repair technique:

Stage 1 is the reconstruction of the recto-vestibular shelf (the perineal body is left open). The wound is dissected to 2-3cm past the defect and then the shelf is closed in two layers - a simple continuous pattern is used in the tissue beneath the rectal mucosa to invert it and a six-bite interrupted purse-string suture is used to close the perineal shelf and vaginal mucosa.

Stage 2 involves the closure of the perineal body 3–4 weeks later. The site should be infiltrated with local anaesthetic prior to surgery. Excess tissue is removed and the edges of skin are sutured from the anal sphincter to the most ventral point of the incision. To eliminate dead space additional sutures may be placed deep to the perineal body. It is important that no sutures are placed in the anal sphincter. Sutures should be removed after 7-10 days.

The Goetze technique is a one-stage operation that involves everting the rectal mucosa into the rectum and vaginal mucosa into the vagina using a purse string suture

Endometrial swabs should be taken once the wound has healed to check for the presence of endometritis.

Question 560

What are the four consistent laboratory findings with DKA?

Answer 560

* Hyperglycaemia, glucosuria, ketonuria, and metabolic acidosis

* CBC, biochem, urinalysis, urine culture, and blood gas analysis

Question 561

What are the classic laboratory findings in hypoadrenocorticism? Diagnosis?

Answer 561

ACTH stimulation test for diagnosis (evaluates the ability of the zona fasciculata and zona reticularis of the adrenal cortex to respond to a maximal stimulus to produce cortisol– animals that do not have enough functional adrenal cortical tissue to respond appropriately)

Na/K < 27:1 (hyperkalaemia and hyponatraemia)

** DDX of hyperK and hypoNa: Addisons, renal and urinary tract disease (anuric renal failure, obstructive uropathy, uroabdomen), severe GI disease, trichuriasis- assosiated pseudohypoadrenocorticism, severe metabolic or respiratory acidosis, peritoneal effusion, chylothorax, CHF, pregnancy, artifacts (erythrocyte lysis in Akitas, marked thrombocytosis, marked leukocytosis)

* Patients with chronic or intermittent GI signs or actue severe GI illness– check Na/K

* fecal analysis is indicated in patients suspected of having hypoA

Question 562

What is atypical addisons?

Answer 562

Patients with secondary hypoadrenocorticism do not have electrolyte abnormalities. Lack only glucocorticoid activity– so they generally present with non-specific signs– chronic or intermittent lethargy, weakness, vomiting, diarrhoea, anorexia, and weight loss….

* Presence of hypoglycemia (symptomatic or asymptomatic), lymphocytosis, eosinophilia, or an inappropriately normal lymphocyte count in a moderately to severely ill patient should prompt consideration of atypical hypoadrenocorticism

** Suspect hypoA in patients with unexplained GI disease/ collapse/ hypoglycemia or other vague illness

Question 563

Laboratory findings associated with GI FBs?

Answer 563

Leukocytosis with a mild left shift

Marked leukocytosis or leukopenia with a degenerative left shift can be present in cases of GI perforation and secondary bacterial peritonitis or sepsis

* Wide variety of electrolyte and acid-base changes have been described

* Proximal GI obstruction- hypochloraemia, hypokalaemia, metabolic alkalosis

* Distal GI obstruction- metabolic acidosis

* Hyperlactaemia and hemoconcentration (increased PCV and TS) are frequently identified

Question 564

Sick kitten at the time of vaccination, do you vaccinate?

Answer 564

No

Question 565

Nitrite and Nitrate poisoning in cattle and sheep

Answer 565

Ruminants vulnerable because ruminal flora reduces nitrate to ammonia with nitrite (10 times more toxic than nitrate) as an intermediate product

* acute - methemoglobin formation= anoxia, secondary effects due to vasodilatory action of the nitrite ion on vascular smooth muscle may occur

* Nitrate- also from accidental ingestion of fertilizer or other chemicals

* excess nitrate in plants- associated with damp weather conditions and cool temperatures (13C) or when growth is rapid during hot, humid summer weather. Drought conditions when plants are immature may leave vegetation with high nitrate concentration. Decreased light or cloudy can increase nitrate concentration of plants

* weak heartbeat, rapid, muscle tremors, weakness, ataxia, subnormal body temperature, brown or cyanotic membranes, pinpoint or larger haemorrhages on serosal surfaces, hydroperitoneum and ascites, edema and haemorrhage in the lungs and digestive system

*Diagnosis: lab analysis of pre and post mortem species– but exposure v. toxicity, plasma is the preferred premortem specimen because some plasma protein-bound nitrite could be lost in the clot if serum was collected

* TX: slow IV injection of 1% methylene blue in distilled water or isotonic saline given at 4-22 mg/kg

* Control: animals may adapt to higher nitrate content in feeds, especially when grazing summer annuals such as sorghum-Sudan hybrids. Multiple small feeds can help animals adapt. Feeding grain with high- nitrate forages may reduce nitrite production.

Question 566

Answer 566

C. Fenbendazole

Question 567

Answer 567

C Ammonium biurate

Question 568

Answer 568

B 14

Question 569

Answer 569

C pain relief and infection

Question 570

Answer 570

D due to longer lasting bupivicaine

Question 571

Answer 571

??

Question 572

Answer 572

D to E

Question 573

Answer 573

C Cranioventral due to inhalation

Question 574

Answer 574

Degenerative myelopathy

Question 575

History and physical exam of a dog with Addison’s

Answer 575

Question 576

Clinical pathology of addison’s

Answer 576

* No stress leukogram but sick patient

* Sick patient has slightly low- low normal BC (especially with low cholesterol +/- albumin)

* Azotaemic patients with other suggestive changes

* Inappropriate relative/absolute bradycardia

* Patients with clinical hypoglycaemia

* Patients with mild hypercalcaemia

Question 577

Addison’s ECG

Answer 577

Question 578

Answer 578

Question 579

Answer 579

Metabolic acidosis

Question 580

Answer 580

A. The Victorian Dept of Economic Development, Jobs, Transport and Resources

Question 581

Answer 581

Question 582

Answer 582

E Kelly forceps

Question 583

Answer 583

Ketamine

Question 584

Answer 584

Question 585

Answer 585

D onions

Question 586

Answer 586

C

Question 587

Answer 587

Gentamicin

Question 588

Answer 588

Buprenorphine

Question 589

Answer 589

Midazolam

Question 590

Answer 590

Lidocaine

Question 591

Answer 591

Ketamine

Question 592

Answer 592

Hypercapnia

Question 593

Answer 593

It requires a low fresh-gas flow rate

Question 594

Answer 594

An 8 year old cat with acute on chronic renal disease following an oesophageal tube placement

Question 595

Question 596

Answer 596

Risk of priaprism

Question 597

Brachycephalic dogs are predisposed to what type of airway disorder?

Answer 597

A: Obstructive disease- brachycephalic dogs often have stenotic nares, everted laryngeal saccules, elongated soft palates, and hypoplastic tracheas, all of which cause obstructions to airflow and increase the work of breathing

Question 598

Increased FiO2 (fraction of inspired oxygen) can cause all of the following except which?

Answer 598

A: Decreased oxygen affinity for haemoglobin - FiO2 does not change oxygen affinity for haemoglobin (and we didn’t talk about this in lecture either)

Question 599

3. Which of the following describes an expected effect of methadone administration?

Answer 599

A: Decreased RR (respiratory rate) - opioids all have the potential to decrease respiratory rate and tidal volume which causes hypoventilation

Question 600

4. True or False: Watching the patient’s chest and reservior bag move can give you an accurate assessment of ventilation.

Answer 600

A: False - ventilation can only be accurately assessed by measuring either the CO2 in the blood (PaCO2) or in the expired gases (EtCO2).

Question 601

What is cancer? What is a tumour?

Answer 601

Tumor (aka neoplasm) -An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancer), or malignant (cancer)

Question 602

Benign v. Malignant

Answer 602

Question 603

How do genes influence cancer?

Answer 603

Question 604

What damage in cells allows cancer to arise?

Answer 604

DNA repair
•
DNA is constantly being damaged
•
Intrinsic
–
DNA replication errors
–
Oxidative damage
•
Extrinsic –carcinogens, UV, radiation, etc
•
Multiple DNA repair mechanisms –may not be perfect
•
‘Lethal’ DNA lesions apoptosis
•
If DNA lesion is not repaired or induction of apoptosis fails, mutation may be passed on to daughter cells
•
Global defects in DNA repair = increased risk of cancer

Question 605

Oncogens and Tumor suppressor genes

Answer 605

Question 606

Cancer risk factors and the genetic basis of cancer

Answer 606

•
Age
–
DNA replication is imperfect -approximately 10^5 DNA lesions/cell/day
–
Increased number of replications = increased risk of mutation cancer
•
Chemical carcinogens –mutagenesis and carcinogenesis strongly linked
•
Tobacco smoke –p53 (tumor suppressor gene) mutations
•
UV light
–
Point mutations in p53 in SCC
–
Also causes oxidative damage, DNA strand breaks

•
Radiation
–
Direct damage –DNA strand breaks
–
Indirect –production of reactive oxygen species
•
Viruses –may insert oncogenes into genome, and/or induce chronic inflammation (oxidative damage)
•
Polyaromatichydrocarbons
–
Bind to DNA –reduced DNA repair activity
–
Oxidative damage
–
p53 mutations

Question 607

Hormones as risk factors for cancer in animals

Answer 607

Question 608

Case 1: Henry; 2-year-old, male, crossbred dog.
Case history: Vomiting for the past 24 hours.
Clinical examination: Mildly depressed. Inappetant. Moderate skin tenting. Abdominal guarding, pain on palpation. Heart rate 100 beats/minute. Respiratory rate 26 breathes/minute.

Answer 608

Question 609

Case 2: Rawnsley; 3-month-old, Male, Irish Wolfhound.
Case history: Puppy is poorly grown and lethargic for its age, when compared to its litter-mates.
Clinical examination: Unremarkable.

Ammonium biurate crystals in urine

Answer 609

Question 610

Case 3: Giddings; 8-year-old, FS, Bloodhound.
Case history: Sudden onset of slight depression and inappetance. Owner’s main concern is that the dog’s mucosae are bright yellow.
Clinical examination: Marked jaundice. Mild depression. Otherwise unremarkable. Abdominal palpation NAD. Urine: bright yellow.

Low Creatinine, high cholesterol, high total bilirubin, conjugated very high, increased ALT and AP

Answer 610

Interpretation: minimal anemia without evidence of regeneration (no polychromasia); mild mature neutrophilia
Differential diagnoses: Anemia – chronic disease or inflammatory disease, chronic blood loss, may be 3rd standard deviation and within reference limits for this dog; Mild
Clinical Pathology Cases: Liver 6
neutrophilia – glucocorticoid response (stress) or adrenaline response (excitement), less likely true inflammation
Further tests: Biochemistry, urinalysis, fecal occult blood

Interpretation: Mild decrease in creatinine (likely clinically insignificant), evidence of hepatocellular damage (increase ALT), evidence of cholestasis (increase bilirubin with large amount being conjugated bilirubin, increased AP, increased cholesterol)
Differential diagnoses: Hepatic or post-hepatic cholestasis due to neoplasia (hepatic, biliary or pancreatic), gallbladder mucocele, pancreatitis, cholangiohepatitis
Further tests: Abdominal radiographs and/or ultrasound, liver fine needle aspirate for cytology
Final diagnosis: Pancreatic adenocarcinoma

Question 611

Signalment: 8-year-old, Quarterhorse gelding
Case history: Apparently normal yesterday. Today ‘colicky’; getting up and down, flank watching, rolling.
Clinical examination: HR 58 b/m, RR 12 br/m, Temp 37.8 C. Not depressed. Slightly yellow OMM and sclera. CRT 1 second

Normal haemogram

Answer 611

Interpretation: Mild decrease in creatinine (likely clinically insignificant), mild to moderate hyperglycemia (consider glucocorticoid induces stress or adrenaline release with pain), evidence of hepatocellular damage (increased GLDH, AST), evidence of cholestasis (increase in bilirubin, GGT and AP), evidence of striated muscle damage (increase CK)
Differential diagnoses: Cholestasis (need to run conjugated bilirubin to help determine type but with degree likely hepatic or post-hepatic with possible contribution from anorexia), cholangiohepatitis, hepatic toxin
Further tests: Conjugated bilirubin, abdominal imaging (likely ultrasound)
Final diagnosis: Cholelithiasis

Ten horses with clinical signs consistent with cholelithiasis were evaluated. Fever, icterus, mild intermittent colic, and weight loss were reported. Clinical laboratory abnormalities included leukocytosis, hyper-proteinemia, and hyperfibrinogenemia. Gamma glutamyltransferase and liver isoenzyme of lactate dehydrogenase activities also were high. Choleliths were observed via ultrasonography of the liver in 5 of the 8 horses evaluated, and increased echogenicity of the hepatic parenchyma and dilated bile ducts were observed in all horses. Seven horses were treated medically, 5 of which died or were euthanatized. Three horses were treated surgically, of which only 1 survived. Cholelith composition varied, but cholesterol, calcium bilirubinate, and mixed bile pigments were most commonly observed.

The horse does not have a gall bladder (which stores bile), so bile from the liver flows directly into the small intestine.

Question 612

Signalment: 3-day-old, Thoroughbred colt
Case history: Appeared to be normal at birth. Has been sucking the mare. Becoming depressed and lethargic.
Clinical examination: HR 180 b/m, RR 15 br/m, Temp 37.5 C. Moderately depressed. Moderately yellow OMM. CRT 1.5 second

Answer 612

Interpretation: Marked anemia, mild hyperphosphatemia, mild decrease in creatinine and urea (may be due to using adult reference values for a foal), moderate hyperglycemia (likely secondary to glucocorticoid stress or adrenaline release with fear), evidence of hepatocellular damage (increased GLDH, increase AST), evidence of cholestasis (increase in bilirubin), evidence of striated muscle damage (increase CK), evidence of bone growth (increased AP)
Clinical Pathology Cases: Liver 11
Differential diagnoses: Neonatal isoerythrolysis or Tyzzer’s disease
Further tests: Coombs test, minor cross matching with mare’s serum and foals red cells
Final diagnosis: Neonatal Isoerythrolysis