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.
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
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.
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
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.
