Formative Assessment

Question 1

Explain the role of Ctenocephalides felis in the transfer of Feline Infectious enteritis

Answer 1

The flea takes a blood meal from the infected host and jumps onto the next host to feed.

It transfers the FIE through the saliva when it takes it’s next blood meal from the uninfected host.

Question 2

Explain the role of Ctenocephalides felis in the transfer of Diplydium caninum.

Answer 2

Segments from DC are passed in the faeces and the eggs are released into the environment.

These are eaten by the larval flea and a cysticercoid develops as the flea develops.

The infected flea moves slowly and clumsily on the animal and is groomed off the host.

The cysticercoid is released into the small intestine and attaches to the intestinal mucosa and grows into an adult DC in 3 weeks.

Question 3

Please explain the procedure used to perform a packed cell volume test on a cat.

Answer 3

Wear gloves.

Select EDTA sample and agitate gently.

Place a plain microhaematocrit capillary tube into the sample and hold the sample
tube at an angle.

Draw blood up into a plain capillary tube – 3/4 full.

Place a finger over the top of the microhaematocrit tube and remove it from the sample.

Wipe the outside of the tube with tissue.

Stop up one end with clay sealant (cristaseal).

Place in microcentrifuge – clay plug outwards fitted against rim.

Balance the centrifuge with another tube opposite Screw down inner safety plate and lock outer lid.

Spin at 10000rpm for 5 minutes (or fast setting).

Dispose of any used capillary tubes and waste as hazardous waste.

Remove tube from centrifuge and measure PCV using a Hawksley Microhaematocrit Reader.

Place tube in groove on reader with the clay seal pointing downwards.

Line up the top of the seal (bottom of the RBC’s) with the zero line at the bottom of the reader.

Move the tube holder across the reader until the top of the plasma lines up with the diagonal line at the top of the reader on 100%.

Move the adjustable PCV reader line so that it intersects with the top of the rbc column and read the measurement on the scale on the right side as a percentage.

Question 4

Which parameters can be assessed through the use of a packed cell volume test?

Answer 4

Anaemia, haemorrhage or dehydration

Question 5

When spun down, what are the three layers of a PCV called?

Answer 5

RBC’S, Buffy Coat and plasma

Question 6

What is the normal PCV range for a cat?

Answer 6

24-45%

Question 7

What is the normal PCV range for a dog?

Answer 7

37-55%

Question 8

Which blood tube would you use to take a sample for a PCV test

Answer 8

EDTA

Question 9

Please explain the procedure to carry out a differential white blood cell count

Answer 9

Wear gloves.

Collect a microscope slide and clean with ethanol (or absolute alcohol methanol) to remove grease.

Dry with a tissue (lint free). Select an EDTA blood tube and agitate gently. Insert a plain capillary tube into the EDTA sample and draw blood into the tube.

Place finger over top of capillary tube to prevent blood escaping.

`Remove capillary tube and place one drop of blood at one end of the microscope slide.

Place capillary tube into hazardous waste.

Select a glass spreader, which is a glass microscope slide with a corner removed.

Make sure it is free of grease.

Hold the microscope slide on the work surface and place the spreader at opposite side to the drop of blood.

Draw the spreader slide back at a 45º angle towards the blood and allow the blood to run along the spreader edge.

Push the spreader forward along the slide with a smooth motion until the drop of blood is spread evenly as a film.

Do not have too large a drop of blood or the film will be too thick.

Allow the film to air dry thoroughly and quickly before attempting to stain.

Label one end with a chinagraph pencil including the date and your initials.

Check and comment on the smear that has been produced.

Stain with Diff-quick stain.

Prepare a small pot of each solution – deep enough to dip a slide completely.

Dip the dried blood smear slide into solution A (blue) for 5 x 1seconds.

Then shake off the excess. Repeat for solutions B (red) and C (purple).

Carefully rinse off the excess solution 3 with distilled water.

Air dry.

Question 10

What is the normal range of SG for a cat?

Answer 10

1.035 - 1.060

Question 11

What is the normal range of SG for a dog?

Answer 11

1.015 - 1.045

Question 12

Please explain the significance of a low urine specific gravity.

Answer 12

Dilute urine.

The animal may have Polydipsia, Chronic renal failure,Diabetes insipidus,

IV Fluid therapy

corticosteroid treatment

Question 13

Please explain the significance of a high urine specific gravity.

Answer 13

Concentrated urine.

The animal may have Dehydration, Acute renal failure,

Diabetes mellitus, Shock, Sediment eg: crystals

Question 14

Please describe the process of viral replication.

Answer 14

Virion attaches to the host cell membrane at receptor sites (if no receptor sites
the cell is resistant).

In the case of bacteriophages the bacterial cell wall is softened by lysozyme from the tail plate.

The tail plate then contracts and the virus or viral nucleic acid enters the cell.

If the whole virus enters it must be uncoated to release DNA or RNA.

The virus takes over control of cells metabolism – redirecting it to produce large numbers of viral components.
Components are re-assembled into fully infective viral particles and released either by a, rupture ( lysis) of the cell. b, budding through the cell membrane (so gain an envelope).

Question 15

Please explain the process of bacterial replication

Answer 15

Binary fission is the asexual division of a bacterial cell into 2 identical daughter cells.

The cell grows and the chromosome replicates.

The cell membrane grows inwards and then the cell wall to form a septum which splits the cell into two identical cells

Question 16

Which organisms may be assessed through the use of a skin scrape?

Answer 16

Demodex canis, Sarcoptes scabeii

Question 17

Which organisms may be assessed through the use of a coat brushing?

Answer 17

Ctenocephalides canis,

Ctenocephalides felis,

Trichodectes canis,

Felicola subrostratus,

Linognathus setosus,

Cheyletiella yasguri

Question 18

Please explain the procedure used to assess if an animal has Microsporum canis.

Answer 18

In some cases of ringworm infection, the hairs will fluoresce when exposed to ultra-violet light (i.e. a Woods lamp).

This procedure should be performed in a darkened room.

Allow the lamp to warm up before shining it onto the animal’s coat. 50% of Microsporum canis isolates will fluoresce an apple green colour.

However this technique is not fool proof and as mentioned only 50% of cases fluoresce so alternative methods should also be used in conjunction with the lamp if the result appears to be negative.

Other substances that fluoresce include surface scale, talc and starch from inside gloves, however they do not appear apple green.

Question 19

Please describe how Toxoplasma gondii reproduces

Answer 19

The final host is the cat.

Oocysts are passed in the faeces of the cat and eaten by an Intermediate host (mouse etc).

These reproduce asexually in the intestine of the Intermediate host.

They can travel to the tissues and divide to form tachyzoites then bradyzoites.

These remain in the Intermediate hosts tissue until the Intermediate host is eaten by the cat.

Question 20

What ratio of tissue to fixative volume is there when sending a sample to a laboratory for tests?

Answer 20

1:10

Question 21

Describe the procedure used to send a sample to a laboratory for testing.

Answer 21

To avoid cross contamination and zoonosis, wear PPE. Check that the sample is preserved correctly, ie: is there adequate formalin? Ensure the container is labelled with the animal’s name, species, breed, age,sex, owner’s name and date. Ensure the container is airtight, moisture proof and robust. Ensure the total volume/mass of the sample in one package does not exceed 50ml or 50g. Wrap the container in sufficient absorbent material to absorb the total volume of fluid in the sample should the container leak or break. Place the sample in a secondary layer eg: plastic biohazard bag. Ensure the laboratory paperwork/form has been completed and place this in a plastic bag separate from the sample. Place all the items into the tertiary layer eg: a prepaid padded bag supplied by the laboratory. Ensure the outer packaging contains the senders name and address. Ensure the outer packaging states the nature of the sample and any special instructions eg: handle with care, fragile, pathological specimen. Ensure the sample is sent by first class post or via a courier

Question 22

What is the term used for assessing a tissue sample?

Answer 22

Histology

Question 23

What colour blood tube would be used to assess for glucose in a sample?

Answer 23

Yellow

Question 24

What does the term lipaemia mean?

Answer 24

Fat globules in the blood

Question 25

What is the significance of the following blood parameter for a cat : Urea 10mmol/l?

Answer 25

This is a normal result as the reading should be 5-11 mmol/l

Question 26

What is the significance of the following blood parameter for a dog: Glu 7mmol/l?

Answer 26

This is a high reading as the range is 3.3-6 mmol/l. This could be due to Diabetes mellitus, stress, post prandial sample, pancreatitis, glucose treatment

Question 27

37. Which parameter on a blood test would be used to assess for pancreatitis

Answer 27

Lipase, amylase

Question 28

38. Please describe the size, structure and appearance of Microsporum canis

Answer 28

Ringworm and is a fungi.

Size 3 um – mushroom sized.

May be unicellular or multicellular and is a filamentous fungi.

It produces hyphae, macroconidia and microconidia.

Each hyphae is a tiny tube filled with cytoplasm and has several nuclei. Macroconidia are 5-15 cells long and colonies of microsporum can grow 3-9cm across within a few days.

Question 29

39. Please describe the size, structure and appearance of Canine Parvovirus

Answer 29

Canine Parvo virus is 20 um in size.

There is no cellular arrangement as they are obligate parasites.

They have a central core of nucleic acid called the genome, surrounded by a protein coat called a capsid.

The capsid is made up of protein sub units called capsomeres.

It is an icosahedral shape.

Question 30

What is another name for the Diff Quick stain?

Answer 30

Romanowsky stain

Question 31

Please explain the procedure to prepare a urine sample for microscopy of the sediment.

Answer 31

Wear gloves.

Mix the urine sample gently and pipette urine into the centrifuge tube.

Centrifuge the sample at 1500 rpm for 5 minutes.

Remove the supernatant, leaving a few drops in which to re-suspend the sediment.

Re-suspend the sediment by ‘flicking’ the base of the tube. Add a stain (Eg: Sedistain or New Methylene Blue) if required.

Pipette a drop of suspension on to a clean labelled microscope slide.

Carefully place a cover slip on top of the sediment.

Avoid creating air bubbles by lowering the cover slip at an angle of 45º.

Dispose of the used pipette, urine and used materials as hazardous
Waste.

Examine the slide using the Battlement Technique under low power,
x10 then x40.

Record any findings. The vernier scale reading can be used to relocate items.

Question 32

What are the implications for a human infected with Toxocara canis?

Answer 32

If the L2 larvae is ingested they will migrate to other tissues.

They can cause damage to internal organs and in severe cases migrate to the back of the eye causing blindness.

Question 33

What advice would you give to an owner of a puppy suffering with Toxocara canis?

Answer 33

Worm using fenbendazole every two weeks until 6 months old and then every 3 months.

Question 34

Which endoparasite is commonly found in hunt kennels?

Answer 34

Uncinaria stenocephala

Question 35

Which endoparasite can cause anaemia in puppies?

Answer 35

Ancylostoma caninum

Question 36

Explain how you would prepare a recumbent horse to collect a Cerebro-spinal fluid sample.

Answer 36

Technique used to assess for neurological conditions such as meningitis. The horse should be placed into lateral recumbency. Clip the hair at the atlanto-occipital space and clean using skin an appropriate skin disinfectant eg: hibiscrub/surgical spirit.

Question 37

Explain the procedure used to collect the Cerebro-spinal fluid from the patient.

Answer 37

It should be carried out by a vet. Personnel should wear sterile gloves and use sterile equipment and consumables. A 20g – 22g needle is advance into the correct space and the CSF allowed to drip out of the hub of the needle into a collection tube. Maximum 1ml/5kg bodyweight using EDTA/plain tubes. The vet slowly removes the needle and point of insertion is covered with a sterile dressing. The syringe and needle are disposed of the sharps bin/bag.

Question 38

Explain how you would prepare a patient for a skin scrape for Sarcoptes.

Answer 38

Assemble the correct equipment: clippers, size 40 blade, gloves, size 10 scalpel blade, liquid paraffin/10% potassium hydroxide (KOH), microscope slides, coverslip, chinagraph pencil, microscope.

Question 39

Explain the procedure used to collect the skin scrape from the patient.

Answer 39

Dip size 10 scalpel blade into liquid paraffin and moisten the skin. Hold the blade between the finger and thumb and stretch the skin with the other hand. Scrape the area 3cm by 3cm until there is capillary ooze. Transfer the sample to a microscope slide and add liquid paraffin to slide. Place coverslip over the sample and label the slide. Set up the microscope and examine under low power x10. Record the Vernier scale readings. Once diagnosed dispose of the microscope slide into the sharps bin.

Question 40

Explain how you would prepare a cat to collect a synovial fluid sample.

Answer 40

Collected by arthrocentesis – needle inserted into a joint cavity. The animal does not need anaesthetised but may require a local anaesthetic. A 2cm – 3cm square area is clipped and cleaned using an appropriate skin disinfectant eg: hibiscrub/surgical spirit.

Question 41

Explain how you would prepare a cat to collect a synovial fluid sample

Answer 41

Collected by arthrocentesis – needle inserted into a joint cavity. The animal does not need anaesthetised but may require a local anaesthetic. A 2cm – 3cm square area is clipped and cleaned using an appropriate skin disinfectant eg: hibiscrub/surgical spirit.

Question 42

Explain the procedure used to take the synovial fluid sample.

Answer 42

An 18g – 23g 1” sterile needle is used. Personnel should wear sterile gloves and use sterile equipment/consumables. An EDTA/Plain tube is used to collect the sample and it should flow freely out of the hub of the needle.