NAVLE 1 Flashcards
A mixed-breed dog weighing 10 kg is being evaluated after having been trapped in a window well without access to food or water for an unknown period of time. The dog’s mucous membranes feel dry to the touch, and a moderate degree of decreased skin turgor is present. The dog’s HR is 220 bpm. The dog is responsive and is standing and walking normally, and pulse quality is normal.
If the degree of dehydration in this dog is approximately 7%, then how many milliliters of isotonic fluid should be administered to replace the dehydration deficit?
A 100 mL
B 250 mL
C 500 mL
D 700 mL
E 1500 mL
Yes, the correct answer is D) 700ml
Fluid needed -
BW(kg) x %dehydration = amt. given (litres) (Ref:Pasquini & Pasquini)
So for a 10kg dog with 7% dehydration
10 x 0.07 =0.70L = 700 ml
or if the weight is given in pounds :)
(BW(lb) x %dehydration) / (2.2) = amt. given (litres)
A SLAP heartworm antigen test with a reported sensitivity of 96% and specificity of 98% is being used. Assuming the prevalence of heartworm in the area is 10%, what is the predictive value positive (PVP) of the test?
A 80%
B 92%
C 84%
D 99%
E 88%
Pick an imaginary number of animals that you test and fill out 2 x 2 table
If prevalence is 10% there must be 100/1000 dogs with heartworm and 900 dogs that are disease free.
A 96% sensitive test will correctly call 96/100 positive (box a) and in correctly call 4/100 negative (box c)
If 100/1000 animals are infected, than 900/1000 are disease-free. Your 98% specific test will correctly call 882/900 disease-free (box d: 0.98 x 900= 882) and in-correctly call 18/900 positive (box b– false positives)
a b c d boxes are filled it… calculate
PVP = a/(a+b)= 96 (96 + 18) = 84%
(pick 1000)
Which of the following causes the highest pre-weaning mortality of piglets in swine operations?
A Crushing by the sow
B Porcine circovirus- associated disease (PCVAD)
C Porcine reproductive and respiratory syndrome (PRRS)
D Scours
E Transmissible gastroenteritis (TGE)
The best answer is A
How/ why does lead cause the following cytological features?
* Basophilic stippling, poikilocytosis, anisocytosis, polychromasia and metarubricytosis
* The main cause of lead’s toxicity is its interference with a variety of enzymes because it binds to sulfhydryl groups found on many enzymes. Lead can mimic many other metals (zinc, iron), important in biological processes, which act as cofactors in many enzymatic reactions, displacing these metals at the enzymes on which they act. But it won’t properly functon as the cofactor. Therefore it will interfere with the enzymes ability to catalyze its normal reaction or reactions.
Treatment of ivermectin toxicity. Do you give atropine? Why or why not?
* Treatment for ivermectin toxicity consists of supportive care (that one case study with ILE, not on collies)
* Ivermectin’s effect on vertebrates is that of a GABA agonist, not an acetylcholinesterase inhibitor. IV lipid therapy can be helpful, as can treatment with activated charcoal.
* But organophosphate and carbamate insecticides are acetylcholinesterase inhibitors and in cases of intoxication with these agents, which cause muscarinic signs, atropine is used to counteract those “SLUD” effects– salivation, lacrimation, urination and defecation.
If you treat a down cow for milk fever in the morning, is it okay for your assistant to return to the farm to give Calcium again?
No, because the cow may have a more serious problem e.g. septic mastitis, twin left inside

Bony lesion in the navicular bone that has a shape similar to a lollipop.
Three pigs in a group of 30 weaner pigs died yesterday. Four additional pigs were found dead this morning. A few pigs in the pen are down and paddling. Some pigs are blind and other appear uncoordinated. These weaners have been off- feed for 3 days. Cultures from necropsy of the dead pigs grow:
* Lungs: Hemophilus parasuis, Streptococcus suis, Pasteurella multocida;
* Pharynx: Hemophilus parasuis, Streptococcus suis, Pasteurella multocida;
* Brain: Streptococcus suis;
* Heart: Streptococcus suis; and
* Pleura: Mixed growth, including Proteus spp.
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Bonus Question 01
Which of the following is the most likely cause of illness in these pigs?
(A) Actinobacillus suis
(B) Hemophilus parasuis
(C) Pasteurella multocida
(D) Proteus spp
(E) Streptococcus suis
The answer is Streptococcus suis because isolation of S. suis from the brain was most likely to assist in the definitive diagnosis of disease.
Which of the following is most likely true of clinically healthy pigs in a typical confinement swine operation?
(A) The pigs do not carry Streptococcus suis.
(B) The pigs are carriers of multiple serotypes of Streptococcus suis.
(C) The pigs are carriers of Streptococcus suis serotype 2 only.
(D) The pigs are carriers of Streptococcus suis serotype 3 only.
(E) The pigs are carriers of Streptococcus suis serotype 9 only.
B. The pigs are carriers of multiple serotypes of S. suis
What are three testing options for newborn foals when neonatal isoerythrolysis (NI) is suspected? Which one is the easy one that can be done quickly on the farm?
- The stall-side, easy test is the jaundice foal agglutination test (mare’s colostrum + foal’s blood). It has a good correlation to actual hemolysis
- Another option is to perform a hemolytic test (mare’s serum + foal’s RBC + complement). Not easily done in the barn, so not as realistic a choice
- Whole blood cross- match– expensive and would take time
** side note there are more than 32 blood group antigens in horses (8 blood types, each with various allo-antigens). Types Aa and Qa are the most often associated with NI reactions
Advantages and disadvantages of collecting peritoneal fluid via abdominocentesis by a needle with syringe vs. use of a blunt teat cannula.
I would suggest using an 18G 1.5-inch or even 3-inch needle (spinal needle). Horse abdominal walls are thick! Also, when using a needle for this purpose, if you pick a good spot and get fluid, you often do not need to attach a syringe. Simple redirection of the needle tip or a twist of the needle can get fluid to flow.
Needles
1) Fewer preparation steps when using a needle vs cannula.
2) Fairly cheap and easy to have a ready supply.
3) Especially in horses with large colon impactions, I think one is more likely to enter a viscus (do an enterocentesis by mistake).
4) If enterocentesis occurs, the local contamination is small with a needle vs with a cannula.
Teat cannulas
1) Requires more preparation (stab incision); maybe more “practice” is required to get the technique right.
2) VERY easy to reposition the teat cannula without traumatizing tissues. This is why I love them.
3) Requires sterilization after each use.
Are Clostridia gram positive or gram negative? What is associated with Tyzzer’s disease?
* Gram variable- “Clostridium are anaerobic or microaerophilic spore-forming rods that do not produce spores in the presence of air, are usually gram positive….although Tyzzer’s bacillus has often been reported to be gram negative in tissue sections, it can appear gram variable and gram positive. Many clostridia stain gram variable or even gram negative once they have aged.”
* Clostridium piliforme- Tyzzer’s disease in horses
What is Tyzzer’s Disease?
“Clostridium piliforme [is] a motile, sporeforming, rod shaped, flagellated, obligate, intracellular bacterium….
”The pathogenesis is poorly understood.
”Infection most likely results from oral exposure, eg, the ingestion of spores shed in the feces of infected animals. Possible sources include infective spores from the environment, contact with carrier animals, and in neonatal foals, ingestion of feces from the dam.
The primary site of infection is the lower intestinal tract with subsequent dissemination via the blood or lymphatics. The bacterium has an affinity for the intestine (epithelial and smooth muscle cells), hepatocytes, and cardiac myocytes. Stress factors such as capture, overcrowding, shipping, and poor sanitation appear to be predisposing.”
And a note for you exotics folks: “Sulfonamide administration predisposes rabbits to the disease.”
Visual signs of dorsal displacement of the soft palate? Epiglottal entrapment?
* DDSP- if the epiglottis cannot be seen, it is completely covered by the dorsally displaced soft palate
* Epiglottic entrapment- when this occurs, the epiglottis itself is entrapped by the aryepiglottic fold. This fold envelops the apex of the epiglottis, but you can still see the shape of the epiglottis. It also sits on top of the soft palate (unlike DDSP)

What is Equine Infectious Anemia (EIA)
EIA noncontagious– but transmitted by blood sucking insects– Retroviridae
* May test for often but will rarely see because of rigorous testing.
Presentation: EIA
- Intermittent fever, weight loss, icterus, can cause abortions. Disease may be inapparent until routine EIA test.
- Typically see in Mississippi River valley and in SE states (Texas to Florida; Texas is a hot spot).
Test of Choice:
- Coggins AGID (1- to 2-day wait for results from state lab)
- Newer ELISA tests allow horse-side Dx in minutes, but one still must confirm a Dx with Coggins.
Rx:
- NONE: typically euthanize positives or isolate for life
- No vaccine, no Rx can clear carrier state.
Prevention/Actions:
- REPORTABLE.
- Stable fly control; isolate foals of positive mares until disease free of EIA (takes up to 6 months, until can be sure maternal ABs are gone).
When should you use AMs for strangles (streptococcus equi subsp equi)?
* Majority of vets will postpone therapy until after abscesses have begun to drain
“The Merck Veterinary Manual” has this to say: “Antimicrobial therapy is controversial. Most authors agree that initiation of antibiotic therapy after abscess formation may provide temporary clinical improvement in fever and depression, but ultimately PROLONGS the course of disease by delaying maturation of abscesses. Antibiotic therapy IS indicated in cases with dyspnea, dysphagia, prolonged high fever, and severe lethargy/anorexia.” (Note: The caps for emphasis are mine.)
How to wash a mare’s RBCs for blood transfusion?
“The reference is Smith’s “Large Animal Internal Medicine” textbook (3rd edition, 2002). The author advocates use of a large volume centrifuge, but serial sedimentation can be used effectively.
1) For a typical 500-kg mare, 6 - 8 L of whole blood can be collected from the dam. 3 - 4 L will provide enough RBCs for most cases.
2) Blood should be anti-coagulated with:
a. Acid-citrate-dextrose (ACD) OR
b. Sodium citrate (3.8% NaCitrate solution; 1 part NaCitrate/9 parts blood).
3) Let anti-coagulated blood settle for 1 - 2 hours OR centrifuge.
4) Draw off plasma aseptically. Add a similar or greater volume of sterile isotonic saline (0.9% NaCl) and mix gently. Let settle for 1 - 2 hours or centrifuge.
5) Draw off saline and discard.
6) One can repeat washing OR re-suspend RBCs in equal volume of 0.9% NaCl and administer.
NOTE: One should follow basic guidelines for administering a blood product, i.e., monitoring body temperature, heart rate, respiratory rate, and flow rate of transfusion. Start slowly!”
Causes of equine abortion
Non-infectious causes
* evil twin (number one cause of non-infectious abortion)
* Evil caterpillars- Mare Reproductive Loss Syndrome (MRLS)
* Evil fungus- fescue toxicosis infected by endophyte Acremonium
Infectious equine abortion
* Equine rhinopneumonitis (Equine Herpesvirus 1)
* Equine viral arteritis
* Bacterial abortion (Potomac horse fever, Leptospirosis, Streptococcus zooepidemicus, misc.)
* Equine mycotic placentitis
What is Verminous Myelitis? What is Equine Protozoal Myelopathy (EPM)?
* Verminous Myelitis- neurological disease due to aberrant helminth migration. Signs vary, but they are usually acute and asymmetric and may be progressive.
* EPM- neurological disease due to protozoa- Sarcoystis neurona, is the principal rule-out for multifocal, asymmetric, neurological disease in horses. It can mimic any neurologic disease, it just depends where the protozoa have caused inflammation in the nervous system, but it is typically characterized by gait abnormalities, muscle atrophy, and down horses.
What is Cervical Stenotic Myelopathy? (CSM)
Equine Wobbler Syndrome– caused by stenosis of cervical vertebral canal. Look for younger horses (1-3 years) with normal mentation, but pronounced hindlimb ataxia, a clumsy “tin soldier” gait, knuckling, and stumbling. You can make the hind end sway when pulling on the tail (positive tail test, suggesting paresis). Exacerbation of symmetric signs with elevation of the head, lack of cranial nerve signs, atrophy, or systemic illness in a young horse suggest CSM.
What is Equine Occipitoatlantoaxial malformation (OAAM)?
Due to a congenital C1- occipital malformation, particularly in Arabian horses. In dogs, atlantoaxial subluxation is most commonly a congenital problem of young toy or miniature breeds.
What is equin degenerative myelopathy?
EDM- also called encephalomyelopathy
A common cause of symmetrical ataxia of all 4 limbs in younger horses, 6-8 months up to more than a year old.
What are the four types of hypersensitivity reactions?
Antibody-mediated mechanisms govern types I, II, and III and occur rapidly while type IV reactions are cell-mediated and take longer. Most diseases actually involve a combination of types of immune-mediated reaction, but this basic classification system is still helpful in understanding allergic disease.
Type I reactions involve IgE and can be generalized (such as anaphylactic shock) or may be more focal reactions, such as urticaria or hives. Type I reactions include facial edema, salivation, vomiting, dyspnea, diarrhea, shock, collapse, and death. In the canine (because the liver is most affected) portal hypertension and visceral blood pooling cause the resultant GI signs.
In type II reactions cell-surface antigens are bound to antibody, forming an antibody-antigen complex that is capable of activating complement and causing cell lysis or causing an antibody-mediated cytotoxicity. IMHA and transfusion reactions involve cytotoxicity. Antibodies bound to cell receptors may also block the activation of the cell (e.g., anti-receptor antibodies in myasthenia gravis).
Type III hypersensitivity is immune complex-mediated. Endothelial deposition of immune complexes causes an inflammatory response and vascular damage. Vasculitis (usually in joints, skin, kidneys, lungs, or brain) results. The site of endothelial deposition of the immune complexes determines resulting signs. Glomerulonephritis, systemic lupus erythematosus, and hypersensitivity pneumonitis in cattle are type III hypersensitivities (as is “farmer’s lung” in people).
Immune complex-mediated hypersensitivity may result from neoplasia or chronic infections, but sometimes the cause of the disease remains obscure.
Type IV hypersensitivity is a delayed type of hypersensitivity. This results when sensitized lymphocytes (TH cells) respond to foreign antigen (or to molecules bound to cells). Contact hypersensitivity (as when some dogs react to plastic collars or bowls) and keratitis sicca are common examples of this type of reaction.
Diagnosing pneumonia in horses
* Radiographs can be used as part of the work up but are not usually the first step nor done alone because you are limited inwhat you can image in an adult horse because of the size and thickness of the chest
* With a bacterial pneumonia, you may be able to show a cranioventral opacity, abscesses (multiple opacities), or a straight line (pleural fluid). You would want to combine with other diagnostics (auscultation/physical exam, ultrasound/echo, [esp. with pleural fluid] TTW, CBC, thoracocentesis, endoscopy, etc.).
Foals are easier to radiograph, being smaller. In a foal with a Rhodococcus equi infection, for example, you might be able to see a “cotton ball” appearance to the lungs, which is where there are abscesses.



































































































































































































































