Week 3 Day 1

Question 1

A feline patient has only been eating canned dog food for the past 8 years. Which of the following are you concerned about?

A. Arrhythmia from a vitamin deficiency
B. Dilated cardiomyopathy
C. Atherosclerosis
D. Hypertrophic cardiomyopathy

Answer 1

B

Dog foods do not contain the amount of taurine that cats need to maintain vital organ function. A taurine deficiency can lead to dilated cardiomyopathy in cats. Hypertrophic cardiomyopathy is seen in cats with a genetic predisposition for the condition. Atherosclerosis is not typically seen in dogs and cats and is more of a human disease.

Question 2

The correct answer is the lesions can be internal and external, so dental radiographs should be taken to further investigate the extent of the lesions. FORL lesions are usually very painful and are more common now than before. Up to 67% of cats presenting for dental care may be affected. The exact etiology of FORL is not known, but studies have shown an association of FORL and diets low in calcium, magnesium, phosphorus, and potassium. Periodontal disease is also often found in association with FORL. Treatment should include addressing associated periodontal disease and possibly extraction of teeth affected by deep lesions. It is likely future teeth will be affected.

Question 3

Cryptococcus is a genus of encapsulated yeast that is often associated with or found in pigeon droppings and eucalyptus trees. The spores are most often inhaled from the environment where these are present. Cats with cryptococcus will often develop a swelling over the bridge of the nose and lesions in the retinas.

Based on the description of the cytology and clinical symptoms of this cat, the most likely diagnosis is Cryptococcus neoformans. This is a fungal disease that occurs when the organism is inhaled and is disseminated to skin, eyes, CNS, lungs, or other areas. The upper respiratory tract is most often involved and symptoms can include nasal discharge, sneezing, swelling over the nose, and regional lymphadenopathy. If the CNS is involved, seizures can also occur. The disease has been thought to be transmitted most often through infected pigeon droppings. Itraconazole, fluconazole, or amphotericin B are the anti-fungals of choice for this disease.

Question 4

The correct answer is cerebellum. Cerebellar dysfunction results in inability to regulate and measure motor function. Clinical signs of cerebellar lesions include ataxia, dysmetria, vestibular signs, delayed postural reactions, and sometimes upper motor neuron signs in the limbs. In utero or perinatal infection of kittens with feline paneukopenia virus often results in cerebellar hypoplasia, leading to the clinical signs mentioned in the question.

Question 5

Tularemia

Question 6

What is the proper location to place an esophagostomy tube?

Answer 6

Left side of the neck

Question 7

The correct answer is hyperadrenocorticism. Hyperadrenocorticism commonly occurs in DKA of dogs, but not in cats. Pancreatitis and bacterial infections commonly occur in DKA dogs and cats. Cardiac disease can be a common concurrent disease in a cat with DKA.
Hyperthyroidism commonly occurs in DKA cats, but not dogs.

Question 8

Topic: Cat Scratch Fever

Bartonellosis. Feline Bartonella is most often caused by Bartonella henselae, a gram negative bacterium that infects the erythrocytes of cats and is transmitted by the flea. If the cat gets flea dirt (digested blood) in their claws from scratching themselves and then scratches a human, the disease can be transmitted.
Most often the infection is self-limiting; however, in immunocompromised humans, the disease can be much more serious and even life-threatening. Despite treatment with doxycycline or erythromycin (the two most efficacious drugs for treatment of cats), most cats will continue to be a carrier of the disease, thus still putting the immunocompromised owner at risk. The cat in question should be started on doxycycline and treated for ectoparasites because the owner recently contracted the disease, and the cat may be actively bacteremic; subclinical cats are typically not treated.

Because the seroprevalence in the cat population can be as high as 30% for Bartonella and transmission of it can typically be prevented, euthanasia is not recommended, especially in asymptomatic cats. L-lysine used to be prescribed as an anti-viral to prevent herpes outbreaks, especially in cats with recurrent ocular/respiratory disease although more recent research shows that Lysine does not have any antiviral properties, but is believed to act by lowering arginine levels and evidence at multiple levels shows that it is not effective for the prevention or treatment of herpesvirus 1 infection in cats.

Question 9

Rabies

Question 10

A 9-year old female spayed Calico cat presents for weight loss. She is strictly indoors with one other cat. There is no travel history. She is
hyperactive at home and has a ravenous appetite. You note she has lost weight from her previous visit. On examination you hear a Il/VI
parasternal murmur. Abdominal palpation is unremarkable. In house lab work shows an ALT of 240 U/L (25-97 U/L), and ALP of 250 U/L (0-45 U/L). Her complete blood cell count is unremarkable. Her blood pressure is 200 mmHg. What do you tell the owner regarding long term care?

Life long therapy is necessary, and control is often successful.
Supportive therapy often fails after a few weeks to months. Consider euthanasia when failure occurs.
Palliative therapy can provide quality of life support, but long term outcome is poor.
Life long therapy is necessary; management and control can be difficult.

Answer 10

Ravenous appetite with weight loss, hyperactivity, heart murmur, and high blood pressure would most likely indicate hyperthyroidism; especially in an older cat. Medical management can be successful with methimazole daily for the rest of the cat’s life. Other treatment options include surgical thyroidectomy (not recommended since surgery can induce hypothyroidism) or radioactive iodine therapy. Hill’s Y/D food has limited iodine, strict dietary management is required for any chance of success if using the Y/D as the treatment choice.
It is important to screen and rescreen for renal disease prior to and after starting methimazole. Hyperthyroidism can mask renal disease due to increased blood pressure and blood flow through the kidneys leading to increased glomerular filtration rate. Owner must be warned that even if no signs are seen prior to initiating treatment, renal disease may be diagnosed at a later time.

Question 11

Rivalta’s test has the highest negative predictive value in the diagnosis of FIP. This means that a negative test is likely associated with the cat truly not having the disease.

Rivalta’s test involves filling a reagent tube with distilled water and 1 drop of acetic acid (98%). On the surface of this solution, 1 drop of the effusion
fluid is added and if the drop disappears and the solution remains clear, the Rivalta’s test is negative. If the drop retains its shape, stays attached to the surface, or slowly floats down to the bottom of the tube as a drop, Rivalta’s test is defined as positive.

Question 12

A 10 year old female spayed Labrador Retriever has presented for difficulty getting up in the hind and apparent back pain for the last 3-4 weeks.
Upon questioning the owner, you are told that her appetite is diminished but she is still eating. An orthopedic exam finds no pain or discomfort elicited on manipulation of the hips or stifles. A neurologic exam identifies substantial pain in the lumbosacral region; however, conscious proprioception is intact, and patellar reflexes are normal.
Radiographs of the lumbosacral region identify a lytic lesion at the L7-S1 endplates as well as surrounding bony proliferation. Which of the following diagnostic tests is likely to provide the most helpful additional information given your findings?

A. Chest radiographs
B. Abdominal ultrasound
C. Blood draw for creatine kinase levels
D. Stifle arthrocentesis
E. Urine culture

Answer 12

The diagnosis you should have in mind is discospondylitis. Be sure not to confuse this with spondylosis, which is typically not clinically

significant and can be expected in most older dogs. The radiographic description is relatively specific for this condition. Neoplasia in the

spine should be lower on your differential list because it typically does not cross joints. Disc herniation cannot be ruled out, and advanced

imaging would be necessary to know for certain, but given the exam and radiographic findings, discospondylitis should be your top
differential.

Discospondylitis is usually bacterial in origin, with Staphylococcus being the most common organism involved. Other organisms identified include Brucella canis, E. coli, Pasteurella, Aspergillus, and Streptococcus.
In an attempt to identify the causative agent, urine and blood cultures should be considered. The other answer choices are not as high yield in identifying the specific bacterial cause or underlying etiology.

Question 13

Meibomian Adenoma image

The correct answer is meibomian adenoma. The description fits the appearance and location of a meibomian gland adenoma. This is the most common ocular tumor of the dog and is usually benign. A chalazion is an obstruction of the meibomian gland and appears as a swelling within the eyelid rather than projecting from it. Entropion is an infolding of the eyelid. Melanoma is a reasonable differential but is less common, especially with the location of this mass at the eyelid margin.

Question 14

The correct answer is observation without treatment. Most cases of canine oral papillomatosis will resolve without treatment in about 3 months. In severe cases, treatment might include surgical removal, laser ablation, or cryotherapy. Although, papillomatosis is usually benign, transformation to squamous cell carcinoma can occur but this is very rare.
Canine oral papillomatosis is very common and affects young dogs. It is caused by papillomavirus, which spreads by direct and indirect contact. Usually infection occurs at sites of damaged skin or mucous membranes.

Question 15

The correct answer is the stomach likely rotated in a counter-clockwise direction. Most GDVs rotate this direction. Many students miss this question because they fail to pay attention to what direction the question is asking to describe the rotation from. If you take the surgeon’s perspective (caudal to cranial), the rotation will be in a clockwise direction. Typically you will encounter a 180-degree twist, but sometimes the rotation may be as much as 270 degrees or even 360 degrees.

Question 16

The correct answer is a portosystemic shunt. Animals with liver shunts are frequently poor doers that are small and may have intermittent signs of hepatic encephalopathy. They often have microcytic anemia. Iron deficiency could cause the microcytic anemia but is unlikely in this case due to the other signs and the fact that iron deficiency is rare in dogs, except in cases of chronic bleeding. Renal dysplasia and
PDA would not cause microcytosis.

Question 17

The correct answer is oxytetracycline. Salmon poisoning commonly occurs in the Pacific Northwest (Washington, Oregon, Northern California, and southern Vancouver Island in Canada). Dogs contract the disease by ingesting raw fish containing the fluke Nanophyetus salmincola which carries the rickettsial organism Neorickettsia helminthoeca.
The most common vector is raw salmon, hence the name. Other cases have occurred from the ingestion of freshwater trout and salamanders. Clinical signs include fever, vomiting, diarrhea, enlarged lymph nodes, and depression. Rare cases can develop neurologic signs such as seizures and muscle twitching.
Because the signs are caused by a rickettsial organism, treatment is with a tetracycline-type of drug. Left untreated, 90% of dogs will die.
Praziquantel is usually given to eliminate the fluke in order to prevent contamination of other waterways.

Question 18

D-pencillamine has also been used to chelate lead, copper, iron and mercury. It is used more commonly for copper toxicity.

Question 19

Ca-EDTA is the chelator used to treat lead poisoning. Succimer can also be given orally.

Question 20

N-acetylcysteine is used for acetaminophen toxicity and hepatotoxicity.

Question 21

Golden Retrievers are predisposed to having splenic hemangiosarcoma and they commonly present as described in the question. A splenectomy will save the patient’s life and provide a histologic diagnosis. Dogs with hemangiosarcoma can be expected to live approximately 3 months after surgery without chemotherapy. If chemotherapy is provided post-operatively, a 6-7 month survival time is expected. Splenic masses can also be benign hematomas which have an excellent prognosis and no further therapy is required.

Question 22

A 4 year-old neutered male Doberman Pinscher presents for symmetrical alopecia, lethargy, and weight gain despite a normal appetite. The owner reports that the dog has recently become very itchy. Upon dermatological examination, you find areas of alopecia on the flanks and axillary region. There is also erythema and waxy crusts involving the axillae and forelegs. You take cytology from these areas and find Malassezia.
Complete blood count reveals a mild normochromic, normocytic anemia. Chemistry panel shows a very mild hypercholesterolemia. What is your next treatment and next diagnostic step?

Answer 22

From the options listed, fluconazole is the best treatment plan for this dog’s Malassezia dermatitis. Griseofulvin is an antifungal but is expensive and causes myelosuppression and gastrointestinal upset; it is not the first choice for Malassezia dermatitis. Other azoles like itraconazole and ketoconazole are also good choices. Terbinafine is being used more often for Malassezia dermatitis since it has fewer side effects than azoles. Ketoconazole, itraconazole, and fluconazole can be hepatotoxic.
Underlying causes of Malassezia dermatitis include allergies, endocrinopathy, immunodeficiency syndromes, and other systemic illnesses.
This dog is presenting with classic signs of an endocrinopathy with initially non-pruritic symmetrical alopecia. The clinical signs of lethargy and weight gain along with the blood work results is indicative of hypothyroidism, and your next diagnostic step would be a free T4.
Intradermal testing is not recommended at this time, since the dog was initially not itchy and only became pruritic presumably after infection with Malassezia.

Question 23

Iatrogenic Cushing’s feedback mechanism

Question 24

PTE should be immediately suspected in any dog with profound dyspnea and unremarkable radiographs. The split second heart sound is heard due to pulmonary hypertension from the PTE. This

Question 25

The breed, clinical history of syncope, radiographic findings, and auscultation findings are most consistent with aortic stenosis. Echocardiography would be the best method for diagnosing the disease in which you would find left ventricular concentric hypertrophy, stenosis of the aortic outflow tract, and post-stenotic dilatation of the ascending aorta.

Question 26

The correct answer is mitral valve dysplasia. This abnormality is a congenital anomaly of the mitral valve. The valve leaflets may be thickened, fused, fibrosed, etc. The chordae tendinae or the papillary muscles attaching to the mitral valve may be irregular as well. German Shepherd Dogs, Great Danes, and other large breed dogs are predisposed to this disease. Myxomatous mitral valve degeneration occurs in older dogs, but would otherwise result in similar physical exam and radiographic findings as those described. Tricuspid dysplasia results in an enlarged right heart, and the murmur would be heard best on the right side of the dog. Aortic stenosis results in concentric hypertrophy of the left heart, which may or may not be detectable on radiographs. Also, the murmur is heard best at the left heart base with aortic stenosis.

Question 27

The correct answer is German Shepherd Dog with hip dysplasia. Canine degenerative myelopathy is a progressive, degenerative spinal cord disease that occurs most commonly in German Shepherd Dogs between 5-9 years of age. This disease causes random axonal degeneration in all spinal cord segments, but it is usually most severe in the thoracic cord. It is a diffuse myelopathy that can look like a transverse myelopathy, and is often confused with hip dysplasia.

Question 28

The image shows a lymph node with metastatic melanoma (the large cell with black melanin pigment). The ONCEPT vaccine, also commonly referred to as the "melanoma vaccine" was given a conditional product license in 2007 and was USDA approved in 2010 as a therapeutic vaccine for cancer treatment. Palladia is a receptor tyrosine kinase inhibitor approved for use in mast cell tumors in dogs. Doxorubicin, vincristine and mitoxantrone are human chemotherapy drugs commonly used off-label in veterinary oncology but not routinely for melanoma.

Question 29

Tetralogy of Fallot is a congenital defect of the heart which includes pulmonic stenosis (not aortic stenosis, dextro-positioned aorta (over-riding), RIGHT ventricular hypertrophy, and a ventricular septal defect. It causes shunting of venous blood across the VSD into the arterial circulation which leads to hypoxemia, and an increased drive for erythropoiesis, causing polycythemia. Affected animals tend be underdeveloped in size and have a history of exercise intolerance, dyspnea, tachypnea, or syncope due to hypoxemia. Thoracic radiographs usually show a normal to mildly enlarged cardiac silhouette with right ventricular enlargement and pulmonary hypoperfusion due to the shunting of venous blood into the arterial circulation.

Question 30

The correct answer is increased right ventricular systolic pressure. Concentric hypertrophy occurs in the right ventricle as a result of the increase in pressure in the right heart caused by the increase in resistance to the ejection of blood through a stenotic pulmonary outflow tract. The post-stenotic dilation develops as a result of turbulent blood flow. The left heart is not affected by pulmonic stenosis.

Question 31

Blood flow of heart

Question 32

This case is most consistent with immune-mediated polyarthritis (IMPA). 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. Nonerosive 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 but it is most commonly idiopathic with no association to another disease process. In the described case, no risk factors or signs of concurrent disease were mentioned. Tick-borne arthropathy is less likely with the negative tick titers obtained, but since not every type of tick can be tested for, some clinicians may opt to treat with an antibiotic like doxycycline concurrently with the immunosuppressive drugs. The clinical signs associated with IMPA are anorexia, weight loss, fever, lethargy, and lymphadenopathy. Up to 25% of dogs present with only nonspecific signs of systemic illness and without apparent gait abnormality or joint effusion. It is an important consideration for dogs with fever of unknown origin and may be the cause up to 20% of the time. IMPA is diagnosed by synovial fluid analysis although additional baseline diagnostics are indicated to screen for potential systemic or infectious causes. Normal synovial fluid is clear and viscous with <2.5 g/dl protein and <3,000 cells/ul with predominantly mononuclear cells. Joint fluid in IMPA may be thin, turbid, and increased in volume with higher amounts of protein and cells, often primarily nondegenerate neutrophils. Treatment of idiopathic IMPA centers on immunosuppressive therapy, often starting with prednisone and sometimes including an additional immunosuppressive drug such as azathioprine or cyclophosphamide. About 80% of dogs will respond to immunosuppressive doses of prednisone; however, about one half of dogs require long-term or additional drug therapy to maintain remission.

Question 33

Iguanas are predisposed to developing large cystic calculi if they are fed an imbalanced/improper diet. Radiographs contribute to the diagnosis, which show classic round cystic calculi within the bladder. If the calculi are large such that they will not pass, surgery may be indicated. In order to promote proper healing and to decrease the chance of calculi recurrence, a balanced diet appropriate for iguanas must be provided.

Question 34

The answer is polyuria and polydipsia. Estrogen secreting Sertoli cell tumors are quite common in cryptorchid testes and cause the clinical signs of truncal alopecia, hyperpigmentation, gynecomastia, urinating in a female position, and bone marrow dyscrasias such as aplastic anemia. Attraction of other males can also occur. PU/PD is a sign commonly seen with endocrinopathies but not this one.

Question 35

What percentage of the kidney must be damaged in order to see laboratory changes consistent with renal insufficiency in horses? The correct answer is 66%. At this point you begin to see isosthenuria due to a decreased ability to concentrate urine. Azotemia will be apparent at approximately 75% damage to the kidneys

Question 36

The correct answer is high PaO2. PaCO2, blood pressure, PaO2, cerebral metabolism, and certain drugs can affect cerebral blood volume and intracranial pressure. In head trauma patients, you want to prevent an increase in intracranial pressure by keeping cerebral blood flow relatively low without causing hypoxia. To keep cerebral blood flow in the low-normal range, the cerebral metabolic rate and PaCO2 should be kept low. Factors that would cause the cerebral metabolic rate to go up include fever, seizures, pain, etc. Mean arterial pressure should be maintained in the normal range to prevent hypotension, hypoxia, and cerebral ischemia.

Question 37

The correct answer is WNV. This is a mosquito born flavivirus that affects horses in multiple areas of the United States. Clinical signs are variable and can be mild (muscle fasiculations, slight ataxia) to severe (recumbency). Of note, muscle fasiculations is somewhat characteristic of WNV but fever may be detected in all patients. A readily available diagnostic test is the serum IgM capture ELISA which will detect infection, even in the face of vaccination. There is a vaccine available for WNV, making the clinical presentation less common.

Question 38

Scratches is a condition of chronic seborrheic dermatitis of the palmar/plantar aspect of the pastern. The condition is sometimes referred to by several other names including "grease heel", "dermatitis verrucosa", "dew poisoning" and "mud fever". It is not specific to the underlying infectious cause but the condition is generally associated with horses kept in wet or muddy environments. Summer sores are caused by Habronema spp. and Draschia spp. stomach worms of the horse. The larvae in feces are ingested by the maggots of flies, and the flies can deposit them at susceptible moist skin areas, damaged skin areas, or mucous membranes where the larvae cause an eosinophilic granuloma as a reaction to their migration. Sweet itch results from a Type 1 allergic reaction to Culicoides spp. Clinical signs of sweet itch are usually in the form of self-trauma due to pruritus. Sweeney is the common name for shoulder atrophy in the horse. The muscle atrophy is caused by damage to the suprascapular nerve which innervates to the infraspinatus and supraspinatus muscles. Ringbone refers to osteoarthritis or bony exostosis in the pastern (high ringbone) or coffin (low ringbone) joints.

Question 39

Based on the history and ruling out other endocrinopathies this patient likely has hair cycle arrest (Alopecia X). The pathogenesis of this disease is not known. This condition is common in Pomeranians, Chow Chows, Alaskan Malamutes, Toy Poodles, and Samoyeds. The most common clinical signs are truncal alopecia and hyperpigmentation. The treatment of choice (if the dog is intact) is to neuter; however, it is not uncommon to see a relapse in clinical signs 1-2 years after neutering. Melatonin may help new hair to grow if a relapse occurs. Trilostane, mitotane, and growth hormone supplementation have been tried with varying success. Levothyroxine is a thyroid supplement and would not be indicated.

Question 40

The key to identifying the disease is the Gram-positive, slender, pleomorphic rods in the liver which suggest this is Erysipelas. Otherwise, other differentials such as Pasteurella, E. coli, salmonellosis, Newcastle disease and others could present similarly. The treatment of choice for Erysipelas is a rapid-acting penicillin simultaneously with erysipelas bacterin. Oral oxytetracycline is not thought to be effective. Amprolium is used for coccidia and copper sulfate and vinegar is sometimes used in poultry to treat crop mycosis or thrush.

Question 41

The correct answer is herpesvirus. Marek's disease is one of the most ubiquitous avian infections. It is highly contagious and can survive for months in the environment.

Question 42

These objects are chondroids, which are concretions of pus and bacteria. They most commonly occur when horses develop guttural pouch empyema, an accumulation of purulent exudate in the guttural pouch due to mucosal infection or drainage from the retropharyngeal lymph nodes with Streptococcus equi subsp. equi (Strangles). This inspissated guttural pouch exudate provides a refuge for the bacteria and allows for continued bacterial shedding. When exudate persists, it can become increasingly dense (inspissated), forming solidified concretions that are difficult to extract and serve as a nidus for prolonged shedding of the organism. To reduce shedding and transmission, these chondroids should be removed and the guttural pouch should be flushed and infused with 5 million units of penicillinG in 3% gelatin. In addition, these horses should be treated with penicillinG intramuscularly for 7 days, isolated for 30 days, and then retested with 3 consecutive series of nasopharyngeal swabs and culture. Animals that remain positive should go through a repeat treatment and culture cycle.