October - November NAVLE Test Sample Questions Flashcards
An 8-year old Quarterhorse brood mare presents with an acute onset of colic. On presentation she has a heart rate of 58, respiratory rate of 28, and is seen rolling on the ground. CRT is approximately 3.0 seconds and mucous membranes are slightly red. Her rectal temperature is 101.6F (38.7 C). Gastrointestinal sounds are completely absent and gastric reflux yielded 15L of brown-to yellow- colored fluid. Peritoneal fluid analysis yielded a cloudy yellow fluid with a protein of 2.8 gm/dl and white blood cell count of 11,354/ul. Which of the following is not a likely diagnosis?
- Small intestinal volvulus
- Epiploic foramen entrapment
- Strangulating lipoma
- Mesenteric rent
Answer: Strangulating lipoma
Explanation
The correct answer is strangulating lipoma. The clinical signs are consistent with any of the answer choices.
However, a strangulating lipoma is least likely to be the case since this horse is still relatively young.
Strangulating lipomas are commonly seen in older horses.
**PowerPage: Top 8 Equine Acute Colics
**PowerLecture: Gastrointestinal Disorders
A relative calls you to ask how she can stop her 4-year old Cockapoo from begging for food at the table. You advise her not to pay any attention to the dog when it is showing this behavior. What behavioral principle is this?
- Negative reinforcement
- Avoidance learning
- Negative punishment
- Noncontingent reinforcement
- Extinction of operant conditioning
Answer: Extinction of operant conditioning
Explanation
Operant conditioning is the use of consequences to modify the occurrence of a behavior. In this case, the dog has learned that begging behavior has previously been met with positive consequences (i.e. being fed or receiving attention). Extinction is the lack of any consequence following a behavior. When a behavior is inconsequential, producing neither favorable nor unfavorable consequences, it will occur with less frequency.
When a previously reinforced behavior is no longer reinforced with either positive or negative reinforcement, it leads to a decline in the response.
Negative reinforcement occurs when a behavior is followed by the removal of an aversive stimulus thereby increasing that behavior’s frequency. An example is a loud noise continuously sounding until a lever is pressed, upon which the loud noise is removed. This will encourage the behavior of pressing the lever.
Negative punishment, also called punishment by contingent withdrawal, occurs when a behavior is followed by the removal of a favorable stimulus, such as taking away a child’s toy following an undesired behavior, resulting in a decrease in that behavior.
Avoidance learning is when a behavior results in the cessation of an aversive stimulus. For example, holding your ears to shield them from a loud, high-pitched sound helps avoid the aversive stimulation of that obnoxious sound.
Noncontingent reinforcement is the delivery of reinforcing stimuli regardless of the animal’s behavior. This causes that behavior to decrease because it is not required in order to receive the reward.
An 8-year old male tomcat presents for having a one week history of progressive lethargy, anorexia, occasional sneezing, conjunctivitis, and nasal discharge. On physical exam you see several ulcerations in the mouth. What is the most likely diagnosis?
- Chlamydophila felis
- Feline calicivirus
- Feline herpesvirus
- Foreign body
- Bordetella bronchiseptica
Answer: Feline calicivirus
Explanation
The correct answer is feline calicivirus. This is a very typical question. It is important to know some of the major differences in feline upper respiratory infections. We hope you did not fall for the foreign body. If you did don’t worry there is hope. Feline calicivirus is known for its ability to cause oral ulceration. Clinical signs associated with this virus include lethargy, anorexia, fever, conjunctivitis, sneezing, nasal discharge, oral ulceration, and, rarely, nasal ulceration. Feline herpes virus presents with conjunctivitis, coughing, sneezing, fever, anorexia, and rarely oral ulceration. You may also see dendritic ulcers in the eye, which is considered pathognomonic for the virus. Cats infected with Chlamydophila will show such signs as conjunctivitis and occasional sneezing. It is usually pretty difficult to distinguish these unless you observe the “red flag” clinical sign such as oral ulcers for FCV.
Transmission of brucellosis in pigs is often via which of the following routes?
- Aerosol transmission
- Vectored by biting insects
- Fecal-oral transmission
- Venereal transmission, and through aborted fetuses
Answer: Venereal transmission, and through aborted fetuses
Explanation
The correct answer is venereal transmission, and through aborted fetuses. Pigs are often infected by ingestion of infected aborted fetuses, fetal membranes, and fluids discharged during abortion. Infection can also occur through infected semen via natural breeding, or poorly planned artificial insemination. Transmission is also possible through broken skin and mucous membranes.
***PowerLecture: Reproduction
A diagnostic ratio is the ratio of income from diagnostic procedures relative to income from goods (i.e. drugs). Which of the following types of veterinarians usually has the lowest diagnostic ratio?
- Avian veterinarian
- Veterinary specialist
- Livestock veterinarian
- Companion animal veterinarian
Answer: Livestock veterinarian
Explanation
Diagnostic ratio is often used as a measure to evaluate productivity. Companion animal veterinarians often have a ratio near 1:1. Avian practitioners often have higher diagnostic ratios and livestock veterinarians usually dispense many more drugs relative to the number of diagnostic procedures they perform and therefore have a low diagnostic ratio (approximately 1:4). The diagnostic ratio of veterinary specialists varies widely by specialty.
Frequently, owners question the value of spaying or neutering a dog. In this case, you have a hesitant owner that has come in with her new female Bichon Frise of twelve weeks of age. Which of the following statements is the most accurate statement?
- Spaying your dog will not eliminate the likelihood of developing a pyometra later in life
- Spaying your dog will result in an 73% chance of a cranial cruciate ligament tear
- Spaying after the first heat cycle will result in an approximately 8% likelihood of mammary cancer
- Spaying your dog will eliminate all inappropriate eliminations in the household
Answer: Spaying after the first heat cycle will result in an approximately 8% likelihood of mammary cancer
Explanation
Spaying is very important in decreasing the incidence of mammary carcinoma. Spaying prior to the first heat results in a 0.5% incidence of mammary carcinoma. A spay after the first heat results in an increased incidence of 8%. Finally, a spay after the second heat yields an approximately 24% incidence of mammary carcinoma.
Pyometra is a disease which manifests itself as a result of hormonal imbalance during diestrus. A properly performed ovariectomy will eliminate the chances of this occurring.
Although there are scattered reports concerning the association of cranial cruciate ligament disease and early spaying, there are currently no definite associations.
Which of these compounds is effective at inducing emesis in the cat?
- Acepromazine
- Xylazine
- Ketamine
- Diazepam
Answer: Xylazine
Explanation
The correct answer is xylazine. Xylazine can cause emesis fairly reliably in cats. The other drugs listed do not.
A 3-year old male castrated domestic short hair cat is given a large dose of oxymorphone for analgesia. Shortly after intramuscular administration of the drug, the cat is excessively sedate and barely rousable. Which drug can be used to reverse the oxymorphone?
- Yohimbine
- Buprenorphine
- Morphine
- Naloxone
Answer: Naloxone
Explanation
The correct answer is naloxone. Butorphanol can also be used to reverse mu agonists like oxymorphone (but it wasn’t in the list of choices). It is a partial mu antagonist, kappa agonist. Morphine is a mu agonist and would have a similar effect on the cat as oxymorphone. Buprenorphine is a partial mu agonist, kappa antagonist and would not effectively reverse the effects of pure mu agonists. Yohimbine is used to reverse alpha 2 agonists such as xylazine. Naloxone is the only opioid antagonist amongst the choices that can be used to effectively reverse the mu agonists.
*** PowerLecture: Opiates
An 8-year old male castrated cat presents to your clinic for a decreased appetite and slight weight loss over the past 2 months. Physical examination is unremarkable except for mild cranial organomegaly detected on abdominal palpation. You perform diagnostic tests and find the following results:
Complete blood count shows:
Hematocrit - 26% (30-45 %)
White blood cell count- 18,155/ul (5,500-19,500/ul)
Neutrophils- 12,100/ul (2,500-12,500/ul)
Lymphocytes- 5,055/ul (1,500-7,000/ul)
Monocytes- 300/ul (0-900/ul)
Eosinophils- 700/ul (0-800/ul)
Platelets- 270,000/ul (300,000-800,000/ul)
Serum chemistry shows:
Creatinine- 1.2 mg/dl (0.9-2.2 mg/dl)
Blood urea nitrogen (BUN) - 22 mg/dl (19-34 mg/dl)
Glucose- 138 mg/dl (60-120 mg/dl)
Albumin= 3.4 g/dl (2.8-3.9 g/dl)
Globulin= 6.2 g/dl (2.6-5.1 g/dl)
ALP- 85 IU/L (0-45 IU/L)
ALT - 214 IU/L (25-97 IU/L)
GGT- 9 IU/L (0-6 IU/L)
Total bilirubin- 0.9 mg/dl (0-0.1 mg/dl)
You perform an abdominal ultrasound and find that the liver appears subjectively enlarged. The echogenicity of the liver is normal and the gall bladder is normal in appearance. No other abnormalities are seen.
You perform an ultrasound guided liver biopsy. Histopathology indicates infiltration of lymphocytes and plasma cells but not neutrophils into portal areas but not into bile ducts.
With treatment, what is the cat’s prognosis?
- Good, mean survival is greater than 2 years
- Poor, mean survival is < 6 months
- Fair, mean survival is about 1 year
- Grave, mean survival is < 2 months
Answer: Good, mean survival is greater than 2 years
Explanation
The case described is consistent with lymphocytic portal hepatitis. Clinically, this condition can appear similar to chronic cholangiohepatitis in terms of signalment, clinical signs and laboratory findings. The key to this diagnosis is the liver biopsy. Typical findings for lymphocytic portal hepatitis is infiltration of lymphocytes and plasma cells but not neutrophils into portal areas. This is in contrast to chronic cholangiohepatitis which typically has neutrophils in portal areas.
Chronic cholangiohepatitis carries a fair prognosis with about half of cats doing poorly (dead or euthanized within 3 months) and half of cats responding favorably to treatment with long term survival. For cats with lymphocytic portal hepatitis, although treatment can be challenging, the disease is very slowly progressive and the reported mean survival is approximately 3 years.
About 1 hour after a difficult labor where the calf had to be pulled out with force, the cow goes down. She is pale and her heart rate is 100/min. What happened?
- Uterine tear
- Hypocalcemia
- Pelvic fracture
- Obturator paralysis
Answer: Uterine tear
Explanation
The correct answer is uterine tear.
With a traumatic fracture or damage to nerves, the cow would have gone down right away rather than an hour later.
Hypocalcemia is possible but less likely in this case where the calf had to be forcibly extracted which can result in a uterine tear, and would be unlikely to make her pale and tachycardic.
It’s Halloween time once again, and you are on the overnight emergency rotation. You have a patient coming down that has ingested an unknown amount of dark chocolate candies about an hour earlier. Which of the following is a clinical sign you may see in a dog with chocolate toxicosis?
- Cardiac tachyarrhythmias
- Miosis
- Hypoglycemia
- Coagulopathy
Answer: Cardiac tachyarrhythmias
Explanation
The correct answer is cardiac tachyarrhythmias. The toxic principle of chocolate is methylanthines (specifically theobromine and caffeine). Methylxanthines can cause CNS excitation, tachycardia, and vasoconstriction. Signs include vomiting, diarrhea, hyperactivity, polyuria, polydipsia, lethargy, tachycardia, cardiac arrhythmias, seizures, and death.
It may also cause pupil dilation (mydriasis), therefore miosis (constricted pupils) is not the correct answer choice. Chocolate ingestion is not associated with coagulopathy or hypoglycemia.
Which of the following is considered to be a component of addressing maladaptive behavior and animal welfare issues?
- Light cycle changes
- Extra water
- Environmental enrichment
- Extra food
- Treats
Answer: Environmental enrichment
Explanation
Environmental enrichment should be used to curb maladaptive behaviors and welfare issues.
What is the end-point of warfarin therapy in an animal with a pulmonary thromboembolism?
- A partial thromboplastin time of 1.5 to 2 times normal
- A thrombin time of 1.5 to 2 times normal
- An activated clotting time of 1.5 to 2 times normal
- A prothrombin time of 1.5 to 2 times normal
Answer: A prothrombin time of 1.5 to 2 times normal
Explanation
The correct answer is a PT time of 1.5 to 2 times normal.
PT is the best of these indexes to monitor warfarin therapy since, at these doses (usually 0.1-0.2 mg/kg), PTT and ACT will be unchanged. An even better method is to use the international normalization ratio (INR), which is a fancy way of taking into account how different PT reactions are run. The goal is to get an INR of 2.0 to 3.0.
A 4-year-old male Akita presents with a foreign body obstruction. You perform an intestinal resection and anastomosis surgery due to the compromised appearance of the intestine at the foreign body site. The dog recovered well after surgery. Five days postoperatively, he presents again with a history of inappetence and has a 104.8 F (40.4 C) temperature. What is the best diagnostic test to confirm your clinical suspicion?
- Abdominocentesis
- Complete blood count and serum chemistry
- Serum lactate
- Abdominal ultrasound
- Thoracic radiographs
Answer: Abdominocentesis
Explanation
You should be highly suspicious of leakage at the surgery site and resultant septic peritonitis. The most common time for anastomosis failure is 3-5 days postoperative;y. This is due to the degradation of fibrin at the site prior to deposition of sufficient collagen.
Abdominocentesis would likely reveal a septic inflammatory process, confirming your clinical suspicion with the finding of intracellular bacteria. A CBC and chemistry are helpful adjunct diagnostic tests but are not specific for septic peritonitis. An abdominal ultrasound would not distinguish between normal postoperative abdominal fluid and/or free gas and a septic effusion. Serum lactate, although helpful, is also not specific for sepsis.
Thoracic radiographs could be useful to assess for less likely complications such as aspiration pneumonia.
Which of these is a possible primary cause for anterior uveitis as shown in this dog with aqueous flare?
- Coccidioides immitis infection
- Keratoconjunctivitis sicca
- Systemic Lupus Erythematosis
- Cataracts
Answer: Coccidioides immitis infection
Explanation
The correct answer is Coccidioides (fungal) infection. SLE causes many signs, but anterior uveitis is not considered one of them. The causes of uveitis include infection (bacterial, viral, fungal, rickettsial), immune-mediated (lens-induced uveitis), neoplasia, hypertension, and trauma. Over 50% of the time, the cause is not found, and the uveitis is termed idiopathic. Chronic uveitis can lead to cataract formation, glaucoma and other eye issues.
You are performing a post-mortem examination on a cow that died of unknown causes. On exam, you find that the liver is enlarged, diffusely lighter yellow in color than usual, and is easily friable. You put a section into formalin and it floats. Which of the following best describes the likely pathogenesis?
- Copper toxicity
- Lipofuscinosis
- Hepatic lipidosis
- Chronic active hepatitis
- Hepatic lymphoma
Answer: Hepatic lipidosis
Explanation
The best choice is hepatic lipidosis. Affected livers usually appear as described in this example due to swelling from lipid vacuoles within the hepatocytes. The section floats in formalin due to decreased density of the lipid vacuoles.
Lipofuscinosis is a storage disease that usually gives the liver a dark appearance. Copper toxicity can cause the liver to appear pale tan or bronze but would not cause the other abnormalities. Chronic active hepatitis will often progress to cirrhosis. Lymphoma could cause the enlarged liver but should not cause the liver to float.
***PowerLecture: Hepatic Disorders
You want to give a 22 pound cat a 5 mg/kg dose of a drug. The drug comes as a 2.5% solution. How many milliliters should you give the cat?
- 4.4
- .4
- 8.8
- 20
- 2
- .2
Answer: 2
Explanation
First, you must recognize that the cat’s weight is given in pounds and should immediately be converted to kilograms. There are 2.2 lbs/kg so this is a 10 kg cat.
Second, you must be able to convert a percent solution to mg/ml. A 2.5% solution is 25 mg/ml. This is hard for some students to remember. A memory tip is that a 100% solution would be 1 gram/ml. Therefore a 50% solution would be 500mg/ml, and a 5% solution would be 50 mg/ml.
The math to solve this question is:
22 lbs x (1 kg/2.2 lbs) x 5mg/kg x (1ml/25mg) = 2 ml
What is the holding layer of the esophagus?
- Submucosa
- Serosa
- Muscularis
- Mucosa
Answer: Submucosa
Explanation
The correct answer is the submucosa. At one time, it was thought that the mucosa was the holding layer, but it has now been shown that it is the submucosa. The submucosa is essentially the holding layer for all hollow viscera.
You are presented with a valuable cow for diagnosis and treatment. She was paste wormed yesterday using a paste gun and benzimidazole wormer. Today she has inappetence, mild bloat, extended head, drooling, and swelling and pain in the throat area. Her temperature is 104.5F (40.3C) on a cool morning. You diagnose ______
- Actinobacillosis
- Choke
- Allergy to benzimidazole wormers
- Malignant catarrhal fever
- Pharyngeal trauma
Answer: Pharyngeal trauma
Explanation
On some occasions, a paste gun or other foreign body such as stick or wire in feed can penetrate the thin mucosa of the pharynx and result in severe acute infection and foreign body reaction. The mild bloat is due to the vagal nerve involvement of the inflamed throat region.
What is the treatment for a persistent corpus luteum that will allow a return to estrus in a mare?
- Progesterone injection
- Gonadotropin-releasing hormone (GnRH) injection
- PGF-2-alpha (prostaglandin) injection
- Human chorionic gonadotropin (hCG) injection
Answer: PGF-2-alpha (prostaglandin) injection
Explanation
The correct answer is PGF-2-alpha injection. PGF will cause lysis of the corpus luteum in mares if the corpus luteum is more than about 5 days old. If you are unsure how old the corpus luteum is, you can repeat the injection in about 7 days. This will allow a return to normal cycling. Remember, injection of PGF may cause mild-moderate abdominal pain (colic, cramping) after administration. Progesterone injection would not change things because the horse already has high levels of progesterone due to the persistent corpus luteum. hCG stimulates ovulation, but if the horse has high progesterone from the corpus luteum, it will not exhibit a behavioral estrus. GnRH would have similar effects.
***PowerLecture: Estrous Cycle
A 9-year old male castrated mixed breed dog presents with a history of intermittent coughing and increased respiratory effort. He had been treated empirically for the past two weeks with antibiotics and no clinical improvement has been appreciated. The owners have finally consented to chest radiographs and those reveal an atelectic right middle lung lobe and no visualization of the bronchi in the region of the middle lung lobe. Which of the following options is the most likely differential?
- Heart failure
- Aspiration pneumonia
- Persistent aortic arch
- Lung lobe torsion
Answer: Lung lobe torsion
Explanation
The history and radiographic findings should help rule out aspiration pneumonia and heart failure. A persistent right aortic arch (PRAA) is highly unlikely as this is a congenital condition diagnosed early on in life. Clinical signs of a PRAA include regurgitation, a ravenous appetite, and a poor body condition. Radiographic signs would show a narrowing of the esophagus at the location of the anomaly and a megaesophagus cranial to the site of the vascular anomaly. Occasionally you will also see a megaesophagus caudal to the vascular anomaly.
We currently don’t know the exact etiology of lung lobe torsions; however deep chested dogs such as Afghan hounds are predisposed. Additionally it is thought that having a pleural effusion or a prior lung lobectomy may facilitate a lobe torsion. Clinical signs are usually similar to those in this question. A tip off to the potential of having a lung lobe torsion is that the bronchi of the right middle lung lobe cannot be visualized. Pleural effusion and atelectasis are also supportive but may also be appreciated other disease processes such as trauma and a lung lobe abscess.
Annotations:
Orange: The right middle lung lobe has a diffuse reticular pattern throughout and associated lobar sign
Green circle: There is abrupt blunting of the main right bronchus after the tracheal bifurcation.
This patient did not have pleural effusion. A large portion of patients with lung lobe torsion do have pleural effusion concurrently.
Radiographs provided by Adrien Hespel, DVM, MS, DACVR and University of Tennessee College of Veterinary Medicine
A 4-year old female spayed Doberman pinscher presents for lethargy and decreased appetite. The owner reports that over the past week, the dog has become increasingly listless and reluctant to go for walks You examine the dog and find mild joint effusion of the tarsi. T-104.3 F 40.2 C, HR-102 bpm, RR-32 bpm. The remainder of your physical exam is unremarkable.
Complete blood count and chemistry panel show:
Hematocrit - 28% (Normal 36%-50%)
White Blood Cell Count - 15,500/ul (Normal 7,000-17,000/ul)
Thrombocytes - 246,000/ul (Normal 200,000-900,000/ul)
Calcium - 9.8 mg/d (Normal 8-11 mg/dl)
Phosphorus - 3.4 mg/dl (Normal 2.4-4.9 mg/dl)
Total Protein - 5.8 g/dl (Normal 5.5-7.3 g/dl)
Alkaline Phosphatase - 68 IU/l (Normal 10-80 IU/l)
Alanine Aminotransferase - 14 IU/l (Normal 3-33 IU/I)
Blood Urea Nitrogen - 20 mg/dl (Normal 10-22 mg/dl)
Creatinine - 1.6 mg/dl (Normal 0.5-2.2 mg/dl)
Glucose - 104 mg/dl (Normal 60-125 mg/dl)
Urinalysis is within normal limits and urine culture was negative. Radiographs of the tarsal joints show joint effusion to no bony abnormalities. You perform arthrocentesis of each tarsal joint. You are able to aspirate about 0.15 ml from each joint; the fluid is thin and turbid. You do not have enough joint fluid to submit for analysis and culture so you make a slide for cytology which shows 3-4 nondegenerate neutrophils per high power field and occasional mononuclear cells. You are suspicious that the dog may have immune-mediated polyarthritis (IMPA). Which of the following are all known potential inciting causes or predisposing factors for this condition?
- Hemangiosarcoma, fungal osteomyelitis, cruciate ligament disease
- Synovial cell sarcoma, renal insufficiency, hyperthyroidism
- Penetrating joint trauma, gastric dilatation-volvulus, ingestion of onions
- Systemic lupus erythematosus, sulfonamide exposure, mammary adenocarcinoma
- Hypothyroidism, anal sac carcinoma, leptospirosis vaccination
Answer: Systemic lupus erythematosus, sulfonamide exposure, mammary adenocarcinoma
Explanation
IMPA is often classified as being erosive or nonerosive. This case is an example of the nonerosive form based on the lack of radiographic evidence of cartilage or subchondral bone destruction. The erosive form is rare and is thought to account for <1% of the cases of IMPA.
IMPA can be associated with a variety of systemic diseases or precipitating factors including systemic infectious, inflammatory or neoplastic disease or reactions to drugs or vaccines. Systemic lupus erythematosus is a progressive multiorgan autoimmune disease which frequently manifests with polyarthritis and may also cause concurrent hemolytic anemia, thrombocytopenia, glomerulonephritis, skin lesions, and lymphadenopathy.
Drug induced IMPA has been associated with a variety of medications including sulfonamides, lincomycin, erythromycin, cephalosporins, phenobarbital, and penicillins. Vaccine associated polyarthritis has been suggested but association has been difficult to prove. Some breeds of dogs have particular predispositions to IMPA including Akitas (in association with meningitis) and Shar-Peis (in association with “Shar-Pei fever”). IMPA can also be associated with chronic infectious or inflammatory diseases including pyoderma, urinary tract infections, pneumonia, endocarditis, mastitis, heartworm, fungal infection, and severe periodontal disease.
Chronic inflammatory bowel disease, intestinal overgrowth, and ulcerative colitis have been associated with IMPA. Distant neoplasia has also been associated with IMPA including squamous cell carcinoma, mammary adenocarcinoma, leiomyoma, heart based tumors, and seminoma.
Maple syrup urine disease is a genetic disorder associated with spongiform changes in the brain and caused by a deficiency of this enzyme in Hereford and polled Shorthorn calves. It usually shows up at 2 to 3 days of age. Which of the following enzymes is the correct one ?
- Pyruvate kinase
- Branched-chain ketoacid decarboxylase
- Acetyl-CoA carboxylase
- Carnitine acyl translocase
Answer: Branched-chain ketoacid decarboxylase
Explanation
The correct answer is branched-chain ketoacid decarboxylase, which will cause accumulation of 2-keto-3-methylvaleric, 2-ketoisocaproic, and 2-isovaleric acids along with their precursors isoleucine, leucine, and valine.
These are excreted in the urine and result in a burnt maple syrup smell (hence the name of the disease). This hereditary disease causes an encephalopathy. Acetyl-CoA carboxylase turns acetyl-CoA into malonyl CoA in fatty acid synthesis. Carnitine acyl translocase helps bring fatty acids across the inner mitochondrial membrane for degradation. Pyruvate kinase turns phosphoenol-pyruvate into pyruvate in the glycolysis pathway.
You have been called to a swine farm with 2400 pigs weighing around 150 lbs because of sudden onset of respiratory signs. Upon arrival you find over 50% of the pigs are coughing. They are off feed and lethargic. The owner reports the coughing just started 2 days ago. The pigs have been vaccinated for porcine reproductive and respiratory syndrome virus (PRRS), Mycoplasma hyopneumoniae, porcine circovirus type 2 (PCV2), and swine influenza. What is your top differential?
- Mycoplasma hyopneumoniae
- Classical swine fever
- Porcine circovirus type 2 (PCV2)
- Swine influenza
- Streptococcus suis
- Porcine reproductive and respiratory syndrome virus (PRRS)
Answer: Swine influenza
Explanation
The correct answer is swine influenza. The rapid spread within a population (>50% in just 2 days) is characteristic for swine influenza. Although this group of pigs had been vaccinated for swine influenza, the great diversity in the virus (especially due to antigenic shift) does not guarantee that the particular vaccine used will contain influenza strains that match or cross protect against the specific virus the herd has been exposed to.
PRRS and PCV2 viruses both can cause respiratory problems in pigs, but they tend to move very slowly within a population. Mycoplasma hyopneumoniae clinically presents as a more chronic problem. Strep. suis can cause pneumonia but usually is more of a problem for an individual or small group of pigs. Classical swine fever is currently not present in the US and manifests as a systemic and enteric problem in pigs and not associated with pneumonia.
What is the treatment of choice for nasal aspergillosis in dogs?
- Systemic antifungal therapy (i.e. traconazole)
- Systemic corticosteroids
- Surgery and antibiotics
- Topical antifungal therapy (i.e. Clotrimazole)
Answer: Topical antifungal therapy (i.e. Clotrimazole)
Explanation
The correct answer is topical antifungal therapy. Topical antifungal therapy is considered more efficacious and less costly than long-term systemic antifungal therapy. Corticosteroids would be contraindicated. Surgery and antibiotics would not be successful in controlling a fungal infection. The currently recognized treatment of choice is clotrimazole, a synthetic imidazole that has an 80% cure rate with single administration. The main potential complication is CNS exposure to the drug if there has been erosion of the cribriform plate.
A 10-year old female spayed Siamese cat presents for a new lump the owner found a month ago. She was spayed last year before she was adopted from the shelter. The owner states that the lump has grown over the last month, and it doesn’t seem to bother the cat. On exam, the 2 cm lump is located on the left 2nd mammary gland, and no other lumps are noted. The lump is freely moveable, and chest radiographs are clear. What is the chance that this tumor is malignant?
- 50%
- 85%
- 5%
- 20%
Answer: 85%
Explanation
70-90% of all feline mammary tumors are malignant. Spaying a cat before 6 months of age reduces the risk for mammary tumors by 7 fold.
The statistics for dogs is a 50:50 chance of malignancy for a single mammary mass.
A 2-month old female Maltese presents for a physical exam. Auscultation of the heart reveals a grade 5 out of 6 continuous murmur heard best over the left heart base. Her arterial pulses are bounding. Thoracic radiographs show an enlarged left heart and pulmonary vasculature. What is the most likely diagnosis?
- Ventricular septal defect
- Patent ductus arteriosus
- Aortic stenosis
- Pulmonic stenosis
Answer: Patent ductus arteriosus
Explanation
The correct answer is patent ductus arteriosus. PDAs results from the failure of ductus closure after birth resulting in a shunt (usually left-to-right) from the aorta to the pulmonary artery. The shunting causes excess volume in the pulmonary arteries, veins, left atrium, left ventricle, and aortic arch. The signalment of the dog and described clinical features and diagnostic findings are classic for PDA. In addition to the enlarged left heart and pulmonary vasculature, there is also usually an aneurysmal bulge of the aorta near the PDA on the DV view.
The bounding pulses result from a widened pulse pressure (difference between systolic and diastolic pressure) because of the run-off of blood from the aorta to the pulmonary artery. PDAs are the most common congenital heart defect in dogs. The most common congenital heart defect in other domestic species is ventricular septal defect.
A Thoroughbred race horse has been moved from California to Florida in July and is experiencing poor performance, exercise intolerance and tachypnea. You observe the horse working out one hot afternoon and see these signs, but you also note that the horse is not sweating. You check the rectal temperature and note that it is 104F (40 C). What is the diagnosis?
- Anhidrosis
- Diabetes insipidus
- Hypothyroidism
- Influenza
- Equine Cushing’s
Answer: Anhidrosis
Explanation
Anhidrosis is the inability to sweat, which can be fatal if not addressed. The cause is unknown. It tends to occur in hot humid climates, and may occur in horses raised in the climate, or more commonly, horses brought into the climate. The most successful treatment is to move the horse back to a more favorable climate.
Treatment of gastric ulceration is extremely common in racetrack medicine. Which of the following is a Hydrogen- Potassium ATPase blocker?
- Omeprazole
- Cimetidine
- Misoprostol
- Sucralfate
Answer: Omeprazole
Explanation
The correct answer is omeprazole. Omeprazole is a proton pump blocker (hydrogen-potassium ATPase).
Cimetidine is an H2 antagonist as well as ranitidine and famotidine. Sucralfate protects the mucosa by binding to ulcers and protecting from further damage. PgE1 analogs (misoprostol) increase gastric blood flow, decrease gastric secretion of acid, and increase mucous and bicarbonate secretion.
A 4-year old dog presents for excessive licking of the right carpus of a 2-month duration. Upon examination you note an oval wound that is thickened, alopecic, and ulcerated. Based on clinical findings you make a presumptive diagnosis of acral lick dermatitis. Which statement is NOT true for acral lick dermatitis?
- Arthritis may be contributing to the lesion
- These lesions are frustrating to treat because an underlying cause can be hard to find
- 50% of cases are diagnosed as idiopathic or psychogenic
- Allergies may be contributing to the lesion
- The lesion should resolve with topical antibiotic treatment
Answer: The lesion should resolve with topical antibiotic treatment
Explanation
Most acral lick lesions are solitary and affect the carpus or metacarpus. About 50% will be diagnosed as idiopathic or psychogenic, but other diseases must be ruled out first including bacteria, fungal, demodicosis, trauma, allergy, and underlying joint disease. A full work-up may include skin cytology, fungal culture, biopsy, diet trial, skin testing, radiographs of the joint, and addressing behavioral disorders.
Most of these lesions will have a deep bacterial infection and treatment should include systemic antibiotics based on a deep culture sample. Topical antibiotics may not penetrate the area well enough to resolve the infection.
Management also includes treating the underlying cause. Many veterinarians will also prescribe topical or intralesional steroids. If no cause is found, then antidepressants or anxiolytics may be started.
These lesions will rarely go away unless the underlying cause is identified and properly treated.
This 2 year-old female spayed Siamese cat presents for further evaluation of the masses seen in the image. The patient was recently rescued and there is no other history available. On physical examination, there are no overt abnormalities appreciated other than the masses visualized. A fine needle aspirate is performed and consistent with a mast cell tumor. Given the breed, the histiocytic subtype is suspected. Which of the following is the most appropriate treatment plan if the owners don’t have unlimited funds?
- Excise the nodules with a minimum of 3 cm margins and one fascial plane deep
- Excise the nodules while obtaining a minimum of 1cm margins
- Monitor as the lesions will most likely spontaneously regress
- These lesions will regress with a 4 week treatment of radiation therapy
Answer: Monitor as the lesions will most likely spontaneously regress
Explanation
Contrary to cutaneous mast cell tumors in dogs, young Siamese cats (less than 4yr) with the histiocytic subtype of mast cell neoplasia will typically have their tumors spontaneously regress. Therefore, as long as the patient is not suffering it is reasonable to wait for these to resolve on their own. In general, it is safe to say that feline mast cell neoplasia is much less aggressive than is seen in dogs. Cutaneous mast cell tumors do not need the aggressive surgical margins that are typically recommended for Grade Il or Ill canine mast cell tumors.
Furthermore, follow up radiation therapy is rarely indicated.
The image below is from an aspirate taken from a lytic bone lesion seen on radiographs of a nine year old female Vizsla dog. Choose the correct cell type of origin AND classification.
- Epithelial origin; carcinoma
- Mesenchymal origin; sarcoma
- Epithelial origin; sarcoma
- Leukocyte origin; round cell tumor
Answer: Mesenchymal origin; sarcoma
Explanation
This is an osteosarcoma. The classification scheme for tumors by cell of origin and cytologic description is:
Sarcoma- These tumors come from mesenchymal cells and are named by the specific cell type such as fibroblasts (fibrosarcoma) and osteoblasts (osteosarcoma). Cytologically, they tend to appear as isolated spindle-shaped cells with elongated cytoplasm and often oval nuclei. Those are the features you should have identified in the image. If you identified several cells that have pink areas in the cytoplasm which likely represent osteoid, well done!
Carcinoma- These tumors come from epithelial cells including cells of glandular tissues such as salivary glands, mammary glands, and cells lining most tissues including squamous cells or transitional cells. The cytologic appearance is that of cohesive clusters of cells. Cells are often polygonal in shape.
Round cell tumors- There are 5 round cell tumors and most but not all come from blood cells. They are lymphoma, mast cell tumors, plasma cell tumors, histiocytic tumors, and transmissible venereal tumors.
Remember, these are sometimes also referred to as sarcomas (i.e. lymphosarcoma or histiocytic sarcoma).
Cytologically, they appear usually as large populations of cells that are not in defined clusters. The cells have a round shape, often with unique identifiable features such as the purple granules in mast cell tumors.
An adult horse presents to you for recurrent seasonal pruritus during the summer months that seems to be worsening. On physical examination, you find multiple excoriations along the poll, mane, and tail. What is the most likely cause of this horse’s pruritus?
- Hypoderma
- Habronema
- Haematobia
- Onchocerca
- Culicoides
Answer: Culicoides
Explanation
The correct answer is Culicoides. Culicoides hypersensitivity, also referred to as sweet itch, occurs due to allergy to the saliva of the gnat. It recurs seasonally in the warmer months and tends to worsen with age. Typically, horses are pruritic and develop lesions on the poll, mane, and tail from self trauma, although ventral midline dermatitis can occur as well. More chronically, scarring can occur. Treatment is to decrease exposure to the gnat and to treat with steroids.
Habronemiasis is a condition where the larvae of the stomach worm migrate and emerge creating granulomatous lesions, usually around the eye, male genitalia, or lower extremities. Inside the granulomas, you can find dead larvae.
Haematobia irritans is a bigger problem in cattle than horses (they reproduce in cow feces) but can affect horses, especially ones that are near cattle. It typically causes ventral midline dermatitis with wheals with a central crust that progress to alopecia and ulceration with fairly focal lesions, rather than more diffuse lesions caused by Culicoides.
Onchocerca can cause dermatitis in the horse due to hypersensitivity to dying microfilariae. Lesions include alopecia and scaling of the ventral midline, face, and pectoral region. Often, lesions are diamond shaped and there may be a “bull’s eye” lesion on top of the head. Onchocerca is nonseasonal, in contrast to Culicoides hypersensitivity, and variably pruritic. Ocular lesions can also occur with Onchocerca including uveitis, conjunctivitis, and keratitis.
Lastly, Hypoderma is also a bigger problem in cattle but can occur in horses and typically creates nodules on the dorsum that have a pore on top.
Which of these is an appropriate treatment for a dog that has ingested diluted bleach within the past 10 minutes?
- Administer apomorphine
- Administer intravenous fluids
- Administer milk to dilute the stomach contents
- Administer non-steroidal anti-inflammatory drugs
- Administer activated charcoal
Answer: Administer milk to dilute the stomach contents
Explanation
The correct answer is to dilute the stomach contents with milk. Bleach, even when diluted can be corrosive as can many household cleaners. This can result in severe burning of the mouth, esophagus, and stomach. Lesions from acids usually appear soon after exposure, while lesions from alkalis may not appear until 8-12 hours later.
Do not induce vomiting with apomorphine because further damage can occur to the esophagus. Activated charcoal does not bind to these products and shouldn’t be used. IV fluids is unlikely to be of any benefit immediately following the ingestion of the bleach unless the animal happens to already be sick or dehydrated.
NSAIDs may help with pain or discomfort but can also contribute to the formation of ulcers within the GI tract.
The recommended course of action is to dilute with milk or water and start Gl protectants for several days. If the patient becomes depressed or anorectic, evaluate it for ulcers.
A female ferret of unknown age presented for acute onset of severe lethargy (see image). The owners obtained the pet 2 weeks ago from an elementary school class which had owned the ferret for 6 years. It is not known if the ferret was spayed. Physical exam reveals depression and thin body condition. Heart rate is 200 bpm. The spleen feels enlarged but no masses are palpable. Blood glucose measures “Lo” on a glucometer. Which of the following treatments are most useful long term for the likely condition?
- Ovariohysterectomy and intravenous fluids
- Prednisone and diazoxide
- Adrenalectomy and trilostane
- Meloxicam and amoxicillin
- Insulin and potassium supplementation
Answer: Prednisone and diazoxide
Explanation
This ferret’s clinical signs and blood glucose are most consistent with insulinoma. Medical management consists of prednisone and diazoxide alone or in combination. Dietary management with a high protein and low carbohydrate diet is also important. Surgical removal of the tumor is also an option in otherwise healthy ferrets.
***PowerPage: Ferret Neoplastic Diseases
A 4-week old intact male Gordon Setter presents for an acutely swollen face and lethargy. On physical examination you note pronounced submandibular lymphadenopathy, and occasional pustules on the face in addition to the swelling. Cytology does not reveal an infectious cause. Which of the following is an appropriate treatment?
- Anti-inflammatory doses of glucocorticoids
- Immunosuppressive doses of glucocorticoids
- Cephalexin
- Ketoconazole
Answer: Immunosuppressive doses of glucocorticoids
Explanation
This is a classic clinical presentation for juvenile cellulitis (puppy strangles). This disease is characterized by sterile granulomas and pustules that respond dramatically to glucocorticoids. The cause is thought to be an underlying immune dysfunction. Immunosuppressive glucocorticoid therapy should not be started until other infectious diseases have been ruled out. At a minimum a deep skin scrape, skin cytology, and trichogram should be performed to rule out Demodex, bacteria, and fungal infection.
An adult macaw presents to you for a cloacal prolapse. The cloacal tissue appears pink but blanches when 5% acetic acid solution is applied, and small fleshy proliferations are seen. What is the likely cause of the prolapse?
- Cloacal papilloma
- Proventricular dilatation disease (PDD)
- Enteritis
- Egg binding
Answer: Cloacal papilloma
Explanation
The correct answer is cloacal papilloma. This is the most common gastrointestinal tumor of birds, and is seen most commonly in Amazons and macaws. A viral etiology is suspected but not proven. Treatment is surgical removal or chemical cautery. Egg binding can cause cloacal prolapse, but does not cause fleshy proliferations.
Enteritis and PDD are unlikely to cause prolapse.
A sheep presents to you for nasal discharge and face rubbing. You perform cytology on the copious discharge and note numerous eosinophils and mast cells. What is the most likely diagnosis?
- Actinomyces sinusitis
- Melophagus ovinus infestation
- Sheep diphtheria (Fusobacterium necrophorum)
- Oestrus ovis infestation
- Enzootic nasal tumor
Answer: Oestrus ovis infestation
Explanation
The correct answer is Oestrus ovis infestation. Adult flies deposit larvae around the animals’ nostrils; the larvae then migrate up the nasal passages into the turbinates and sinuses. With time and multiplication of the larvae, hypersensitivity develops with the marked clinical signs of nasal discharge and face rubbing and shaking.
Secondary bacterial infection can occur. The discharge usually contains numerous eosinophils and mast cells, which confirms the diagnosis in this case. Further confirmation could be achieved with radiographs showing mineralized bots or with endoscopy, but this is not usually necessary.
Enzootic nasal tumor could have similar clinical signs but tends to cause more dyspnea and would not have the eosinophils and mast cells seen in the discharge.
Fusobacterium causes necrotic laryngitis in sheep when there is perforation to the mucous membranes.
Clinical signs are more of coughing and dyspnea; there would not be nasal discharge. Actinomyces pyogenes infection is also unlikely to cause nasal discharge and if it did, you would not observe eosinophils and mast cells in the discharge. Treatment of Oestrus ovis is with ivermectin.
A 4-year old female Brittany Spaniel presents for further evaluation of suspected dystocia. Her gestation length is approximately 60 days and the owners note that she has been extremely restless, panting, and vomited once in the past 8 hours. On vaginal examination, there is no obviously obstructed puppy. Radiographs of the dog show no evidence of fetal gas or alteration in spatial relationship between the fetal bones. What is the best treatment for this dog?
- Perform a Caesarian section
- Administer intramuscular dexamethasone sodium phosphate
- Continue to monitor carefully without disturbing her and have the dog return in 24 hours if she has not delivered the puppies
- Administer intramuscular oxytocin
Answer: Continue to monitor carefully without disturbing her and have the dog return in 24 hours if she has not delivered the puppies
Explanation
Based on the history and clinical examination findings, this dog has presented in stage 1 of labor. This stage is typically 6-12 hours of length and can persist for up to 36 hours. In this stage, it is expected for the dog to exhibit panting, trembling, nesting behavior, and restlessness. Occasionally dogs will also vomit. At this point, there is sub-clinical uterine contraction and dilation of the cervix. Stage 2 will also last approximately 6-12 hours (and persist up to 36hr) and is characterized by abdominal straining which coincides with uterine contraction.
Puppy delivery occurs during Stage 2 at an interval of 30-60min (up to 4 hours). Stage 3 involves the expulsion of fetal membranes as well as involution of the uterus. Fetal membranes are usually passed 5-15 minutes after birth of a pup before another puppy can be delivered from the same horn.
Thick greenish discharge (lochia) is seen in all stages of labor and may persist for up to three weeks.
Complete uterine involution and endometrial recovery occurs in approximately 3 months.
Having just repaired a femoral fracture on an 8 year old male Labrador with mild chronic renal insufficiency, your technician asks you for post operative orders. Which of these drugs is contraindicated for analgesia in your patient?
- Carprofen
- Butorphanol
- Ketamine
- Gabapentin
- Tramadol
- Dexmedetomidine
Answer: Carprofen
Explanation
Carprofen is a non-steroidal anti-inflammatory and has analgesic properties but may exacerbate the chronic renal disease by causing decreased blood perfusion to the kidneys by vasoconstricting the afferent arteries by diminishing the effects of prostaglandins. Dexmedetomidine and ketamine can each be used as a constant rate infusion to provide pain control. Butorphanol is an opioid that has partial agonist and antagonist effects on the mu and kappa receptors. Tramadol is a synthetic opioid. Remember Tramadol is now a controlled substance.
Gabapentin is an anticonvulsant that is often used for its analgesic effects, particularly against neuropathic pain.
Suzie-Q, a 6-month old female spayed domestic short hair was recently adopted from the humane society. She has had watery diarrhea since adoption. Her fecal float and Giardia ELISA tests were negative. She was treated with metronidazole with no clinical improvement. You soak a cotton tip swab with saline and swab the rectum. You see elongated motile oval shaped protozoan organisms that do not look like Giardia lamblia. What organism might this be and what is the appropriate therapy?
- Enterobius vermicularis, Fenbendazole
- Tritrichomonas foetus, Ronidazole
- Cryptosporidium, Clindamycin
- Paragonimus kellicotti, Praziquantel
- Giardia intestinalis, Fenbendazole
- Taenia taeniaformis, Praziquantel
Answer: Tritrichomonas foetus, Ronidazole
Explanation
Tritrichomonas foetus is a flagellated parasite most commonly found in kittens that have had an unresponsive diarrhea. The parasite can be very difficult to diagnose. It is most often responsive to Ronidazole.
Paragonimus is a lung fluke. The eggs are typically passed in the feces. Fenbendazole and Praziquantel have been effective against this parasite.
Giardia is unlikely if the ELISA is negative as it is a very sensitive test.
Taenia is a tapeworm and is not a flagellated parasite. It is treated with Praziquantel.
Cryptosporidium is a coccidian that invades the small intestinal villi after ingestion of infected oocysts. It can be diagnosed with PCR. It is treated with clindamycin, azithromycin, or tylosin most commonly. It is usually an opportunist, so evaluation for underlying disease is appropriate.
Enterobius vermicularis, or pinworm, is a parasite of people and primates but not cats and dogs.
A local farmer calls you because they are having reproductive problems in their 600 head sow farm. For the past month they have been having trouble with sows not becoming pregnant. The heat cycles in about 20% of the sows have been quite unusual. These sows seem to be in heat for 5-6 days. They have been breeding them once a day as long as they are in heat. Their semen costs are getting out of hand and their 30 day pregnancy check for the past 2 weeks has only been 60%. Gilts appear to be affected more severely. Some gilts even seem to be in heat all the time. The farmer knows they had been busy emptying the manure pit and spreading manure on nearby fields most of last week which has changed their usual time for heat checking sows. This week they went back to their normal breeding schedule but are still having problems. What would you recommend they do next?
- Collect nasal swabs from 10 affected sows for influenza virus testing
- Collect blood samples for 20 sows (10 affected and 10 non-affected) for parvovirus testing
- Collect gestation and lactation feed samples for mycotoxin testing
- Collect a water sample for nitrogen testing
- Collect a urine sample for leptospirosis testing
Answer: Collect gestation and lactation feed samples for mycotoxin testing
Explanation
The correct answer is to collect gestation and lactation feed samples for mycotoxin testing; specifically zearalenone testing. The indications of a prolonged heat cycle suggest high estrogens. This is a case of cystic ovarian disease. High levels of zearalenone mycotoxins in the feed are the most common cause of cystic ovaries in swine. Although, parvovirus causes reproductive problems, it usually causes a high incidence of mummies. Leptospirosis manifests as late term abortions. Influenza virus infections cause an acute respiratory outbreak with high fevers and abortions. Clinical signs associated with nitrate poisoning include high respiration rate, increased incidence of diarrhea, reduced feed intake, poor growth, and increased abortions.
When considering a dog that is hypoventilating you realize that the dog is in
- Metabolic alkalosis
- Metabolic acidosis
- Respiratory acidosis
- Respiratory alkalosis
Answer: Respiratory acidosis
Explanation
The correct answer is respiratory acidosis. There is bound to be some sort of acid-base question on the exam. This question might look tricky, but it is truly simple. Think about the information you are given; all you know is the dog is hypoventilating.
So there is build up of CO2; in effect the dog is in respiratory acidosis. Remember, CO2=Acid. Since you have no other information, there is no way to diagnose a metabolic acidosis or alkalosis.
Some causes of respiratory acidosis include airway obstruction, open pneumothorax or flail chest, neuromuscular disease, abdominal enlargement, pleural space disease, and bicarbonate therapy.
Which of these chemotherapeutic drugs causes irreversible tissue sloughing if the drug is perivascularized or given any route other than IV to a dog?
- Cisplatin
- L-Asparaginase
- Doxorubicin
- Mitoxantrone
Answer: Doxorubicin
Explanation
The correct answer is doxorubicin.
Perivascularization of this drug causes a severe irreversible tissue slough that may require amputation.
Some other chemotherapy drugs such as vincristine cause a more localized severe reaction if perivascularized. L-Asparaginase can be safely given subcutaneously or intramuscularly.
Cisplatin can be given intralesionally.
Carboplatin is always given IV but if perivascularized, does not cause a severe reaction.
You perform thoracocentesis on a cat with pleural effusion. The fluid has a hazy gold color and a protein content of 7 g/dl and 7,000 cells/uL. These cells are primarily non-degenerative neutrophils with lesser numbers of other white blood cells and mesothelial cells.
What is the most appropriate interpretation of these findings?
- This effusion is strongly suggestive of
neoplasia - This effusion is strongly suggestive of FIP
- This is a chylous effusion Your Answer
- This effusion is a classic exudate; the cat has
pyothorax
Answer: This effusion is strongly suggestive of FIP
Explanation
The correct answer is that this effusion is strongly suggestive of FIP. FIP causes a classic straw or gold colored effusion with high protein content (about equal to serum protein) and moderate cell counts.
An exudate would tend to have somewhat higher cell counts and lower protein. The protein content is not consistent with chyle or neoplasia.
***PowerPage: Feline Infectious Peritonitis and Enteric Coronavirus
Which of the following is the most likely cause of lymphoplasmacytic rhinitis as seen in this patient?
- Canine adenovirus-2
- Bartonella
- The specific etiology is still unknown
- Parainfluenza virus-3
Answer: The specific etiology is still unknown
Explanation
As the name implies, these patients have a mixed population of lymphocytes and plasma cells when biopsied. Many consider the condition to be an idiopathic immune-mediated disorder. PCR studies have been performed in affected patients in search of parainfluenza virus-3, canine adenovirus-2, Bartonella, and Chlamydophila.
None of these agents were found to be a potential cause. Typical clinical signs include a history of unilateral or bilateral nasal discharge of several months duration. Large-breed dogs are more often affected and the age may vary.
An 11-year old female spayed Siamese cat presents for consultation on a mass found on her ventral abdomen. The cat was previously used for breeding and was just spayed and adopted by her owner 4 years ago. The mass was noticed about a month ago and has grown slightly since it was first found. The mass is firm, painless, and measures 3 cm in diameter. You perform a fine needle aspirate of the mass, which shows a proliferation of abnormal appearing epithelial cells most suggestive of a mammary carcinoma. What is the cat’s prognosis?
- The cat’s long-term prognosis is good only if
she is treated with chemotherapy after surgery - The cat’s long-term prognosis is poor because
surgery is ineffective at treating these tumors - The cat’s long-term prognosis is poor since most mammary carcinomas in cats will metastasize
- The cat’s long-term prognosis is good because
the tumor was found early while it is still small - The cat’s long-term prognosis is good since
most mammary carcinomas in cats do not metastasize
Answer: The cat’s long-term prognosis is poor since most mammary carcinomas in cats will metastasize
Explanation
Mammary tumors in cats are almost always malignant and the large majority of them will eventually metastasize. This is in contrast to mammary tumors in dogs, in which 50% are malignant, and 50% of those that are malignant will eventually metastasize. Similar to dogs, cats that are spayed after they have had one or more heat cycles have a much greater risk of developing mammary tumors.
If staging shows no visible evidence of metastasis, treatment is generally aimed at surgical removal of the tumor followed by chemotherapy to try and slow the development of metastasis. Generally, the type of surgery that is recommended is a unilateral mastectomy to remove all of the glands on the affected side to reduce the risk of recurrence in those glands. The tumor is also greater than 2 cm in size, which is associated with a worse prognosis in cats.
Mucosal disease, or alternatively, chronic Bovine Virus Diarrhea (BVD) occurs in cattle when:
- A 5-month old calf is persistently infected with a strain of BVD virus which coats platelets; platelets are then removed by the RE system resulting in a bleeding diathesis.
- BVD type 2 infects a 5-month old calf.
A 5-month old calf is infected with CPE
biotype of BVD virus and then superinfected with a nonCPE biotype of BVD virus. - A 5-month old calf which was persistently infected as a fetus with a non cytopathic (nonCPE) biotype of BVD virus is superinfected with a cytopathic (CPE) biotype of BVD due to rearranging of the parent non-CPE viral RNA.
- A 5-month old calf which was persistently infected with the nonCPE biotype of BVD virus as a fetus forms antigen-antibody complexes which cause a fatal immune-mediated disorder.
Answer: A 5-month old calf which was persistently infected as a fetus with a non cytopathic (nonCPE) biotype of BVD virus is superinfected with a cytopathic (CPE) biotype of BVD due to rearranging of the parent non-CPE viral RNA.
Explanation
This is the correct answer because it describes the current understanding of the pathogenesis of both mucosal disease and chronic BVD.
A 5-month old calf is infected with CPE biotype of BVD virus and then superinfected with a nonCPE biotype of BVD virus is incorrect because it does not say that there was persistent fetal infection; also, the order of the superinfection is the reverse of what causes mucosal disease or chronic BVD.
A 5-month old calf which was persistently infected with the nonCPE biotype of BVD virus as a fetus forms antigen-antibody complexes which cause a fatal immune-mediated disorder is incorrect because this is not the mechanism by which mucosal disease or chronic BVD occur.
All other answer choices are incorrect because they each describe one of the acute clinical syndromes from primary infection, rather than either mucosal disease or chronic BVD.
***PowerPage: Bovine Viral Diarrhea
A 1-year-old macaw is presented to you for necropsy after recent arrival at a pet shop subsequent to quarantine. It had acutely become anorexic and depressed with ruffled plumage. At necropsy, you find necrotic foci in the liver (see image) and kidneys as well as splenomegaly. Histopathology shows Cowdry type-A intranuclear inclusion bodies in the liver and renal parenchyma. Which of these is a likely diagnosis?
- Infectious coryza
- Newcastle disease
- Avipoxvirus infection
- Pacheco’s disease
- Marek’s disease
Answer:: Pacheco’s disease
Explanation
The correct answer is Pacheco’s disease, caused by a herpes virus. The incubation for this disease can be longer than most quarantine periods. The clinical findings and necropsy results are consistent with this infection, and the finding of the inclusion bodies confirms the diagnosis.
Marek’s disease is also caused by a herpesvirus, and is characterized by lethargy and unilateral leg paresis.
Avipoxvirus infection causes scabbing skin lesions or diptheric lesions in the respiratory tract.
Infectious coryza is a bacterial disease that causes nasal discharge and facial swelling.
Newcastle virus causes signs that can range from respiratory, Gl, or neurologic signs.
***PowerPage: Psittacine Viral Diseases
A dwarf rabbit presents for a right sided head tilt and history of circling to the right. Which of the following is a likely diagnosis?
- Encephalitozoon cuniculi
- Treponema cuniculi
- Myxomavirus
- Bordetella bronchiseptica
Answer: Encephalitozoon cuniculi
Explanation
The correct answer is Encephalitozoon cuniculi.
There is a high prevalence of E. cuniculi although it only infrequently causes disease. Head tilt and torticollis are the common clinical signs.
Treponema cuniculi is the causative agent for rabbit syphilis. Bordetella bronchiseptica is part of the normal flora of the rabbit respiratory tract and does not generally cause clinical signs.
Myxomavirus can be a common cause of pneumonia.
Which of the following tests has the highest specificity for 200 cats, 100 with the disease and 100 without?
- 85 true positive, 85 true negative, 15 false negative, 15 false positive
- 95 true positive, 65 true negative, 5 false negative, 35 false positive
- 75 true positive, 95 true negative, 25 false negative, 5 false positive
- 50 true positive, 80 true negative, 50 false negative, 20 false positive
Answer: ** 75 true positive, 95 true negative, 25 false negative, 5 false positive**
Explanation
The correct answer is 75 true positive, 95 true negative, 25 false negative, 5 false positive. Specificity is determined by the percentage of true negatives versus false positives in cats that do not have the disease of interest.
***PowerLecture: Epidemiology - Sensitivity
A 4-month old kitten arrives at your clinic with a 3-day history of anorexia, lethargy, vomiting, and diarrhea. On physical exam the cat is 5% dehydrated and has a temperature of 103.9F (39.9 C). What is your primary differential?
- Feline panleukopenia virus
- Foreign body
- Feline infectious peritonitis
- Feline immunodeficiency virus
Answer: Feline panleukopenia virus
Explanation
The correct answer is feline panleukopenia virus. These clinical signs most closely correlate with panleukopenia.
One must piece together the signalment, history, and clinical findings. Usually a cat with a foreign body will not have diarrhea and a fever. It is unlikely for a 4-month old kitten to have FIV due to maternal antibody protection. It is also unlikely for FIP to present in such a manner. With the wet form of FIP, you may see dyspnea due to pleural effusion and abdominal distention due to ascites. With the dry form of FIP it will depend on the organ that is affected. You may see a hepatopathy, splenomegaly, renal failure, etc.
You are asked to examine a pen of very young dairy calves (4 to 8 weeks of age) with the complaints of aural discharges, head tilts (see image), and ataxia. You also find one with facial paralysis and another with unilateral nystagmus as you examine them. The affected ones have fevers of 103 to 105F (39.4 to 40.6 C). What organism is most likely to be causing these signs?
- Histophilus somni
- Mycoplasma bovis
- E. coli
- Mannheimia hemolytica
- Salmonella dublin
Answer: Mycoplasma bovis
Explanation
M. bovis may be spread to young calves via milk. In very young dairy calves it can cause otitis media with aural discharge, head tilt, nystagmus, ataxia, and even facial nerve paralysis.
It also causes respiratory disease and can cause arthritis and tenosynovitis in older calves. Mastitis, abortion and other signs can also be caused by M. bovis.
A long time client of your clinic is concerned because four of her cats recently started itching. The owner explains that she recently brought home a new kitten from a shelter and after a few days all of her cats became pruritic. On physical examination you observe hypotrichosis and widespread miliary dermatitis. Some cats have crusted lesions on the tip of their pinnae. All cats have intense scaling over the rump. You perform an acetate tape impression and observe multiple mites on low power. Which mite are you most concerned about?
- Demodex canis
- Sarcoptes
- Pneumonyssoides caninum
- Demodex cati
- Cheyletiella
Answer: Cheyletiella
Explanation
Cheyletiella mites are large mites that affect cats, dogs, rabbits, and humans. This mite is highly contagious which is why all of her cats are itching after introduction of the new kitten (likely the source of infection). The incidence of Cheyletiella has declined in the United States due to the use of topical flea preventatives. The mites live in the stratum corneum and, unlike Sarcoptes, these mites do not burrow. This mite can be found with acetate tape impressions, fecal examination (identify the eggs), or using a flea comb. Lime sulfur dips or flea products can be used for treatment.
Demodex canis and cati live in hair follicles and you would not find these mites on acetate tape. They would require a deep skin scrape. Also, Demodex canis only affects dogs and Demodex cati is not contagious. A good differential for this case would be Demodex gatoi, which is contagious and can be found on acetate tape since it lives in the stratum corneum.
Sarcoptes rarely infects cats. This mite is very difficult to find. Superficial skin scraping would be needed since this mite burrows into the stratum corneum.
Pneumonyassoides caninum is a nasal mite that can result in facial pruritus. Dogs are mainly affected. Diagnosis is by mite identification grossly with rhinoscopy or in nasal flushes.
You diagnose a colony of mice with lymphocytic choriomeningitis (LCM). What is your next step?
- Euthanize the colony
- Do nothing; the disease is self-limiting
- Notify the federal authorities
- Treat aggressively with antibiotics
Answer: Euthanize the colony
Explanation
The correct answer is to euthanize the colony. LCM is caused by an RNA arenavirus. The disease is a zoonotic concern, so euthanasia is recommended for animals affected with the disease.
The image shows radiographs from a newborn calf which sustained a fracture of the tibia during delivery. You do not have surgery facilities nor equipment. What is the best NONsurgical method for repair?
- Apply full-length fiberglass cast and Thomas splint
- Apply heavy cotton wraps from the foot to the hip, confine calf in sling
- Apply Thomas splint from foot to hip
- Apply fiberglass cast from foot to stifle
- Put calf in small water bath so that he is barely weight-bearing for 24 hours a day for 6 weeks
Answer: Apply full-length fiberglass cast and Thomas splint
Explanation
A calf this age will tolerate a cast and splint well and the bones tend to heal rapidly, usually in 6 to 10 weeks (even this ugly tibial fracture). The cast must be changed every two to three weeks as the calf is growing rapidly at this stage. The cast can reach from the bottom of the foot up to the stifle. The Thomas splint goes from the pelvis to the foot and minimizes stifle movement.
Annotations:
Green Circle. There is moderate soft tissue swelling surrounding the fracture.
Complete, closed, markedly comminuted fracture of the left tibia
Orange line: Fissures line
Radiographs provided by Adrien Hespel, DVM, MS, DACVR and University of Tennessee College of Veterinary Medicine
The swinging flashlight test is often used in ophthalmologic exams to check pupilary responses in each eye. A positive Marcus Gunn sign is considered pathognomic for diagnosing a unilateral prechiasmal lesion. Which of the following is observed?
- When light is directed into the normal eye, the pupil in the abnormal eye will stay dilated
- When light is directed into the abnormal eye, the pupil on that side will constrict
- When light is directed into the abnormal eye, the pupil in the normal eye stays dilated I
- When light is directed into the normal eye, the pupil in that eye stays dilated
Explanation
Normally, when light is directed into the eye, the signal is transferred from the retina, through the optic nerve, past the chiasm and down the optic tract. From there, it is directed to both oculomotor nerves to cause pupil constriction bilaterally. When there is a pre-chiasmal lesion, light shining in the abnormal eye will have an interrupted signal that cannot get past the chiasm and both pupils stay dilated. When light is shone into the normal eye, both pupils will constrict due to cross-over fibers that stimulate the oculomotor nerve of the abnormal eye.
Swine dysentery is caused by which of the following?
- Isospora suis
- Coronavirus
- Trichuris suis
- Lawsonia intracellularis
- Brachyspira hyodysenteriae
Answer: Brachyspira hyodysenteriae
Explanation
The correct answer is Brachyspira hyodysenteriae (formerly known as Serpulina hyodysenteriae).
Swine dysentery causes mucohemorrhagic diarrhea. Fibrinonecrotic typhlitis and colitis occur, but the small intestine is unaffected. Those affected include 3 week olds to adults that were previously unexposed.
Lawsonia intracellularis causes proliferative enteropathies. Trichuris suis is a whip worm. Corona virus causes porcine epidemic diarrhea and transmissible gastroenteritis.
PowerLecture: Gastrointestinal Diseases
A herd of pigs is presented for multiple 1-2 cm round papules, pustules, vesicles, and scabs on their ventral abdomens. Young and growing pigs are most severely affected. What is the most likely diagnosis?
- Erysipelas
- Pseudorabies
- Swine pox
- Greasy pig disease
Answer: Swine pox
Explanation
The correct answer is swine pox. The disease is caused by a poxvirus that causes the skin lesions described in the question. All ages can be affected, but it is more commonly seen in young and growing pigs. The disease is often transmitted by biting insects, particularly lice. The disease usually does not require treatment, unless the lesions become secondarily infected. Broad-spectrum antibiotics may be helpful in this situation. Hog lice and insect vectors should be investigated and eliminated to help control swine pox. Erysipelas causes diamond-shaped skin lesions and necrosis of the ears and tail. Greasy pig disease or exudative epidermitis is caused by Staphylococcus hyicus. It causes dark, greasy, brown skin lesions in the axilla, groin, head, and face.
Pseudorabies affects the CNS, respiratory system, and causes reproductive failure.
***PowerLecture: Dermatology
During routine surveillance of a rainbow trout hatchery, the younger fish are noted to be swimming in an erratic pattern. On closer evaluation, the fish seem to be deformed around the head and spine. One of these fish is sacrificed for necropsy, and diffuse necrosis of the cartilage and spores in the cartilage are observed. What is your diagnosis?
- Hole in the Head disease
- Ich (Ichthyophthirius multifiliis)
- Gill rot
- Whirling disease
Answer: Whirling disease
Explanation
The correct answer is whirling disease. The causative agent is Myxobolus (aka Myxosoma) cerebralis which is a myxosporean parasite of salmonid fish. Rainbow trout are most commonly affected and the parasite can cause deformation of the head and spine resulting in the inability to swim properly. Skeletal deformation is not seen in the etiologies of the other potential answers. Ich results from a protozoan parasite that causes white spots on the gills and skin, along with erratic behavior.
Hole in the Head disease is seen in tropical fish, especially cichlids, with pitting-like lesions of the head and lateral line. The etiologic agent of Hole in the Head is still controversial and likely includes multiple factors including poor water quality, improper nutrition, and heximita infection.
Gill rot is a fungal disease caused by Branchiomyces spp. with clinical signs related to respiratory distress due to thrombosis and necrosis of the gills.
What species are primarily affected by both internal and external caseous lymphadenitis, a manifestation of Corynebacterium pseudotuberculosis?
- Cows and sheep
- Goats and pigs
- Pigs and horses
- Sheep and goats
- Horses and cows
Answer: Sheep and goats
Explanation
The cutaneous abscesses caused by this organism also affect cattle. Horses experience pectoral abscesses, internal abscesses, and other sites, as well ulcerative lymphangitis (also caused by C. pseudotuberculosis) of the limbs.
***PowerLecture: Caseous Lymphadenitis
Demodicosis often coincides with bacterial infections. On a recheck examination of an 8-month old pit bull with demodicosis you find swelling and furunculosis over the lateral thighs that is draining serosanguinous fluid. Cytology of the fluid reveals 4+ cocci, and you diagnose a deep bacterial pyoderma. You culture the lesion and start Clindamycin based on the culture results. The dog returns in four weeks for another recheck examination. No bacteria are found on cytology, and clinically the dog looks excellent. You repeat a skin scrape and find Demodex mites. You inform the owner to continue Ivermectin. What should you do regarding continuation of antibiotics?
- Continue the antibiotics for another 2 weeks.
- Discontinue the antibiotics, since cytology was negative and the clinical signs have resolved
- Perform another culture and if positive keep treating; if negative discontinue antibiotics
- Continue the antibiotics until the demodex has resolved
Answer: Continue the antibiotics for another 2 weeks.
Explanation
Deep pyodermas involve tissues deeper than the epidermis including the dermis and even subcutis. Most often deep infections have resulted from an uncontrolled superficial infection. Deep lesions usually heal on the surface before the deeper infection is resolved; making clinical cure difficult to assess. Therefore, antibiotic treatment should be continued for 7-21 days after the tissues return to normal. In general, deep infections can require 6-8 weeks of antibiotic treatment and even 12 weeks for severe cases. Superficial infections require 3-4 weeks of antibiotic therapy or one week past clinical resolution.
Culture results will often be positive in normal dogs since normal dogs will have bacteria on their skin surface and in hair follicles. It is better to manage based on clinical signs. Cytology can miss deeper infections and it is better to extend antibiotic treatment even if cytology is negative.
It is not necessary to continue the antibiotics until resolution of demodicosis. Keep in mind that many Demodex patients will require several months of treatment. It is better to prevent recurrence of bacterial infections with topical therapy such as benzoyl peroxide shampoos.
A middle-aged spayed female ferret presents with progressive bilaterally symmetric alopecia. You are suspicious of adrenal gland disease and run sex steroid hormone blood levels. Which of the following hormones is not usually elevated in ferrets with adrenal disease?
- Androstenedione
- Estradiol
- Cortisol
- 17a-hydroxyprogesterone
Answer: Cortisol
Explanation
Cortisol levels are usually within normal limits. Therefore, many of the tests that are used in small animals to diagnose Cushing’s disease (corticotropin stimulation test, dexamethasone suppression test) are not useful for ferrets.
Adrenocortical hyperplasia/neoplasia should be considered in any ferret that presents with a non-inflammatory alopecia. The prevalence of this disease in the United States is estimated at 70%. Genetic factors, early sterilization, and prolonged photoperiod from indoor housing likely contribute to the high incidence. In ferrets, adrenal gland disease is most often due to hyperplasia followed by adenocarcinoma and then adenomas. Other clinical signs include pruritus, lethargy, sexual aggression, vulvar swelling, dysuria/stranguria, tenesmus, and mammary gland enlargement.
Treatment of choice is adrenelectomy. Other treatment options include leuprolide acetate (long acting gonadotropin releasing hormone agonist) and deslorelin acetate (GnRH analog).
A breeding pair of blue and gold macaws (Ara ararauna) are laying eggs that are being taken for artificial incubation. As seen in the image below, several of the eggs have died near hatch (between 21-24 days of incubation). Egg necropsy, combined with microbiology, demonstrates a bacterial infection with Pseudomonas aeruginosa. Which of the following could be performed to try to salvage the remaining eggs in the incubator?
- Decrease incubation temperature
- Inject eggs with nystatin
- Inject eggs with piperacillin
- Increase incubation temperature
- In-ovo vaccination with Pseudomonas bacterin
Answer: Inject eggs with piperacillin
Explanation
A normal, healthy egg should hatch sterile. Occasionally, eggs may be infected by low level bacterial contamination. Infection may occur as a result of ovarian, oviductal or cloacal infection. Contamination is by minute cracks or pin-holes in the shell at the time of handling or egg collection.
All eggs should be candled so that any non-viable eggs may be removed from the incubator prior to possible contamination of healthy eggs. The incubator should be sanitized.
Pseudomonas infection in eggs can be treated by injection of an appropriate antibiotic such as piperacillin. A small hole is drilled, using a sterile 27 gauge needle over the air cell, and the antibiotic is injected into the air cell.
The hole is sealed with white, water-soluble glue (being careful not to cover additional areas of the shell as this would reduce water loss from the egg during incubation). Any chick that hatches should be cultured for bacteria immediately upon breaking open the shell, and antibiotic therapy should be commenced depending on the culture results. Nystatin should be given concurrently at 100,000 U per 400 g of body weight to prevent secondary infections with Candida spp.
The image shows radiographs from a newborn calf which sustained a fracture of the tibia during delivery. You do not have surgery facilities nor equipment. What is the best NONsurgical method for repair?
- Apply heavy cotton wraps from the foot to the hip, confine calf in sling
- Put calf in small water bath so that he is barely weight-bearing for 24 hours a day for 6 weeks
- Apply Thomas splint from foot to hip
- Apply full-length fiberglass cast and Thomas splint
- Apply fiberglass cast from foot to stifle
Answer: Apply full-length fiberglass cast and Thomas splint
Explanation
A calf this age will tolerate a cast and splint well and the bones tend to heal rapidly, usually in 6 to 10 weeks (even this ugly tibial fracture). The cast must be changed every two to three weeks as the calf is growing rapidly at this stage. The cast can reach from the bottom of the foot up to the stifle. The Thomas splint goes from the pelvis to the foot and minimizes stifle movement.
Annotations:
Green Circle. There is moderate soft tissue swelling surrounding the fracture.
Complete, closed, markedly comminuted fracture of the left tibia
Orange line: Fissures line
Radiographs provided by Adrien Hespel, DVM, MS, DACVR and University of Tennessee College of Veterinary Medicine
You diagnose a dog with a larger left to right ventricular septal defect with advanced sequelae to the abnormality. Which of the following is the most likely radiographic appearance of this dog’s thorax?
- Left atrial and left ventricular enlargement with pulmonary hyperperfusion
- Enlargement of all 4 heart chambers and hyperperfusion of the pulmonary vasculature
- Right ventricular and left atrial enlargement with pulmonary vasculature hypoperfusion
- Right ventricular enlargement with pulmonary hyperperfusion and a normal left heart
Answer: Left atrial and left ventricular enlargement with pulmonary hyperperfusion
Explanation
The correct answer is left atrial and left ventricular enlargement with pulmonary hyperperfusion. In dogs with a VSD, the shunt occurs during systole when both ventricles are contracting so blood is shunted from the left ventricle almost directly into the pulmonary artery. The right ventricle acts as a conduit between the left ventricle and pulmonary artery and is less commonly affected by the shunted blood. The excess blood flow is found in the pulmonary vasculature, left atrium, and left ventricle, thus enlarging these structures.
A 5-year old cow presents with skin lesions confined to the nonpigmented areas (see image). The affected skin is dry and raised at the periphery. The skin of the teats appears dry. Which of the following could result in this presentation?
- Ingestion of lupine
- Ingestion of moldy feed containing aflatoxins
- Ingestion of Pteridum aquilinum (bracken fern)
- Ingestion of Quercus spp.
Answer: Ingestion of moldy feed containing aflatoxins
Explanation
This is a case of photosensitization based on the skin lesions confined to the nonpigmented areas. Primary photosensitization can occur when photodynamic agents are absorbed from the G.l. tract such as Hypericum perforatum (St. John’s wort), Fagopyrum esculentum (buckwheat), Ammi majus (bishop’s weed), and Cymopterus watsonii (spring parsley). Secondary (hepatogenous) photosensitization occurs when the liver’s excretion of phylloerythin is impaired due to liver damage. Phylloerythin is derived from the breakdown of chlorophyll by rumen microbes. The best answer in this question is aflatoxins because they are known to cause liver damage.
Bracken fern toxicity causes acute hemorrhagic syndrome in cattle. Lupine toxicity primarily causes birth defects. Quercus (oak) toxicity causes Gl and renal dysfunction.