Vet prep Flashcards
A male goat presents for vocalizing and straining to urinate. He has been kicking at his abdomen. You detect crystals adherent to the hairs around the prepuce (see image). What condition should you suspect and try to rule out first?
a) Lower intestinal obstruction
b) Acute severe pyelonephritis
c) Urinary tract obstruction
d) Upper intestinal obstruction
c)
The correct answer is urinary tract obstruction due to calculi. This should be suspected in all male and castrated male goats (and sheep) with non-specific signs of disease or discomfort because it is so common. Common clinical signs associated with urinary tract obstruction are vocalization and dribbling of urine. Heaving or forceful abdominal contractions may be seen. Hematuria, dysuria, prolonged urination, and apparent abdominal pain are also common signs. The most important step of evaluation is exteriorization of the penis and examination of the urethral process because this is the most common site of blockage. In severe cases the entire urethra may be filled with calculi.
Which of these is the most common cause of seizures in the adult ferret? a) Hypocalcemia B) Hepatic encephalopathy c) Intracranial neoplasia d) Hypoglycemia e) Idiopathic epilepsy
d)
The correct answer is hypoglycemia. Hypoglycemia secondary to insulinoma is the most common cause of seizures in the adult ferret. Keep in mind, a prolonged seizure can actually cause hypoglycemia, so the finding of low blood glucose in a seizuring ferret does not necessarily confirm a diagnosis of insulinoma. Idiopathic epilepsy has not been reported in ferrets. Hypocalcemia and hepatic encephalopathy can cause seizures, but are not as commonly reported as hypoglycemia.
A 4-year old female spayed mixed Chihuahua presented to the emergency service at approximately 5am this morning after presumptively being attacked by a coyote. The patient has a flail chest and it is questionable if there is direct communication between the thoracic cavity and the environment (it was difficult to examine the dog due to her fractious nature). Exploration of the wound was performed, and once anesthetized, it was apparent she had a pneumothorax. The patient must be ventilated, as there is no vacuum present in the chest for lung expansion to occur. What pressure should the anesthetist not exceed if manually bagging the patient during anesthesia?
a) 8cm H2O
b) 20cm H2O
c) 12cm H2O
d) 24cm H2O
b)
Pressures above 20cm H20 may result in barotrauma. In an otherwise healthy patient it is not recommended to exceed this pressure. In patients with chronic atelectasis, anesthetists will be much more apprehensive about over ventilating or ventilating the lungs too quickly, as acute expansion can trigger re-expansion pulmonary edema, which may then lead to acute respiratory distress syndrome and death.
A 4-year old male neutered Pit Bull mix comes in to your clinic because his owner thinks he might have gotten into rodenticide while she was out of the house 2 hours ago but is not sure. You send her to bring back the box of rodenticide and induce emesis by administering subconjunctival apomorphine. Within 5 minutes, the dog vomits the material shown in the image below. You rinse out the conjunctiva and administer oral activated charcoal. The owner returns with a box of rodenticide that says brodifacoum. What should you recommend?
a) Treat the dog with vitamin E and selenium
b) No additional treatment or monitoring is needed
c) Hospitalize the dog for 24 hours to monitor and treat potential neurologic signs
d) Treat the dog with vitamin K1 for 6 weeks
e) Check serum calcium levels today and once weekly for 6 weeks
d)
The bright green vomit confirms the owner’s suspicion of rodenticide ingestion because many rat poisons contain a bright green dye. Dogs that ingest these products may have bright green vomit or stool. Brodifacoum is a vitamin K antagonist commonly used in rodenticides. Ingestion of this compound causes hemorrhaging after several days due to a lack of production of new clotting factors. Treatment for this condition requires vitamin K1 administration for 4-6 weeks.
A 6-month old feedlot steer, which entered the feedlot 4 weeks ago, has lost weight and is now showing an enlarged left flank as shown in the image below. On exam, you find the left side of the abdomen to be gas-filled under moderate pressure, and the rumen to be otherwise poorly filled and with poor motility. Based on percussion and auscultation, the animal also appears to have chronic bronchopneumonia. What is the most likely cause of the rumen malfunction?
a) Free gas bloat, failure to eructate
b) Frothy bloat
c) Type 3 vagal indigestion
d) Cecal dilation
e) Left displaced abomasum
a)
This is sometimes called Type 1 vagal indigestion, or free gas bloat. It is frequently associated with swollen mediastinal lymph nodes caused by pneumonia. The signals to or from dorsal rumen receptors, which detect gas pressure and open the cardia, are compromised such that eructation does not occur normally and free gas bloat occurs. This in turn causes the calf to feel full and it eats poorly and loses weight. One needs to treat the pneumonia and perhaps create a temporary rumen fistula to allow the escape of gas until eructation returns to normal.
A horse is suspected of having the muscle disease rhabdomyolysis, and you are seeking a laboratory test to help confirm the diagnosis. Of the following, which test would likely be the most helpful?
a) Sorbitol dehydrogenase (SDH)
b) Creatine kinase (CK)
c) Anion gap
d) Gamma glutamyl transferase (GGT)
e) Ionized phosphate
b)
CK, also called, CPK, is found in muscle cells and is elevated in the serum when muscle damage occurs.
A 3-year old, indoor-only, male castrated Maine Coon cat is presented to you for acute-onset of hindlimb pain and paresis. Physical examination reveals a grade III left parasternal heart murmur and minimal movement in the hind legs. Femoral pulses are bilaterally absent, and the hindlimb toes are cold to the touch. The cat is tachypenic, but lung sounds are normal. What is the most likely diagnosis?
a) Tetanus
b) Thrombus at the aortic bifurcation (saddle thrombus)
c) T3-L3 intervertebral disc disease
d) Lymphoma of the spinal cord
e) Chlorpyrifos toxicity
b)
Maine Coon cats are predisposed to development of hypertrophic cardiomyopathy at a young age. Consequently, left atrial enlargement predisposes to atrial thrombus formation, and these clots frequently lodge in the arterial supply to the hindlimbs. The trifurcation is where the aorta divides into the two external iliac arteries and the common origin of the internal iliac arteries. Classic findings due to a clot at the aortic trifurcation include posterior paresis/paralysis, hindlimb pain, cyanotic nailbeds, absent femoral pulses, and a firm leg musculature. Other signs of cardiac disease/failure (murmur or pulmonary edema) are often but not always evident at presentation.
Neither cord lesions, tetanus, nor toxicities should cause the vascular compromise evident on this cat’s physical exam.
A 4 year old mare has bilateral swelling and drainage of the mandibular lymph nodes. Rectal temperature is 101.8F (38.8 C). Which of the following is the most appropriate plan for this horse?
a) Inform the state veterinarian
b) Administer penicillin
c) Administer corticosteroids
d) Culture the discharge for bacteria
d)
The correct answer is to culture the discharge for bacteria. The most likely diagnosis for this horse is equine strangles. Strangles most commonly affects younger horses (<5 years of age), but can cause disease in any age horse. The etiologic agent of this disease is Streptococcus equi subsp. equi. The diagnostic test of choice to confirm this is bacterial culture. While awaiting culture results, the horse should be separated from any other horses, as strangles is highly contagious to other horses. Antibiotic therapy is controversial and thought to lengthen the course of disease rather than shorten it when given at this stage; also, it may possibly interfere with the natural immunity acquired from natural infection. Strangles is a reportable disease.
When performing a subtotal colectomy on a feline patient, what blood vessel limits the amount of colon that you are able to remove?
a) Pudendal artery
b) Caudal mesenteric artery
c) Ileocolic artery
d) Left colic artery
c)
The correct answer is ileocolic artery. The site for colonic resection is limited by tension on the ileocolic artery when trying to suture your new end of colon to the rectum. Sometimes the tension is too great and instead of a colocolic anastomosis, an ileocolic anastomosis must be performed. Essentially you are trying to connect a section of ascending colon to the rectum. Now that can be pretty far! Performing an ileocolic anastomosis is not ideal because you eliminate the ileocecal valve, and that may predispose the animal to bacterial overgrowth. The caudal mesenteric artery gives branches to the rectum and descending colon. The left colic artery also feeds the descending colon. The pudendal artery supplies the external genitalia. The ileocolic artery provides blood supply to the ascending and transverse colon.
A 11-year old male castrated Golden Retriever presents for collapse with muffled heart sounds on examination. You ultrasound the heart and obtain the following image; the right atrium (RA) and right ventricle (RV) are labeled. A large mass is seen in the right atrioventricular groove with pericardial effusion. What is the likely diagnosis?
a) Pulmonary adenocarcinoma
b) Chemodectoma
c) Hemangiosarcoma
d) Idiopathic pericardial hemorrhage
e) Lymphoma
c)
The correct answer is hemangiosarcoma. Hemangiosarcoma of the heart has a predilection for the right auricle of dogs, with Golden Retrievers being predisposed. Stabilization of this patient will require pericardiocentesis; prognosis is guarded and may include chemotherapy, pericardiectomy, or rarely auriculectomy. Chemodectoma arises from the ascending aorta and heart base; lymphoma is rare in the heart of dogs and is more commonly metastatic than a single mass. Idiopathic pericardial hemorrhage is incorrect because of the clear evidence of a mass.
A 1-year old mixed breed stray dog is presented for extreme pruritis and the lesion shown in the picture (lésion rouge, alopécie). The dog was recently found and adopted off the street and has been itching despite being bathed and treated with flea preventatives. The owner reports that she has been itching and developing rashes on her own body since adopting this dog. Your physical exam shows that the dog has several additional similar lesions on the other legs, chest, and ventral abdomen. What is the most likely diagnosis?
a) Sarcoptes infestation
b) Cutaneous lymphoma
c) Squamous cell carcinoma
d) Demodex infection
a)
The key to this question is that Sarcoptic mange is extremely pruritic and can be transmitted to people, including this dog’s owner. Diagnosis of this disease is usually based on clinical impression and potential for exposure to the mites. A positive skin scraping would be most definitive, but scrapes often come back negative and trial therapy would need to be instituted.
Demodex is not transmittable to people and does not typically cause extreme pruritus like Sarcoptes.
Lymphoma and squamous cell carcinoma are less likely because they typically would occur in older animals and neither are usually particularly itchy.
Many turkeys on a poultry farm develop whitish “wart-like” nodules and scabs on the comb, wattles, feet, and vent. Which management intervention would help prevent spread of the disease?
a) Mosquito control
b) Add antibiotics to the drinking water
c) Tick control
d) Thoroughly disinfect pens and equipment
e) Raise the room temperature 5 degrees
f) Immediate removal of fecal waste
a)
The condition described here is the dry form of avian (fowl) pox. This is a relatively slow spreading disease that can be spread by contact or by mosquitoes that may harbor infective virus for greater than a month.
In the dry form of the disease, the main sign is raised, whitish wart-like lesions on unfeathered areas (head, legs, vent, etc.). The lesions heal in about 2 weeks. Unthriftiness, decreased egg production and retarded growth may be seen. Mortality is low with this form of the disease. The wet form mainly involves the oral cavity and upper respiratory tract. Lesions are diphtheritic and can ulcerate or erode mucous membranes. Marked respiratory involvement can lead to mortality.
A diagnosis is usually based on flock history and presence of these lesions. This is a pox virus and there is no specific effective treatment but there is a vaccine. Disease control is best accomplished by preventive vaccine as sanitation alone will not prevent spread of disease. Several vaccines are available and a single application results in permanent immunity.
There are not many tick borne poultry diseases but they may include spirochaetosis and Pasteurella infection.
Raising the temperature 5 degrees may be part of the treatment for infectious bronchitis in chickens. Disinfecting pens +/- quarantine is done for quail bronchitis, aspergillosis, and ulcerative enteritis. Antibiotics in the drinking water are most effective for preventing secondary bacterial infections and for mycoplasma but not preventing spread of the virus.
What species is the principle carrier and vector of Malignant Catarrhal Fever (MCF) virus in North America?
a) Bison
b) Horse
c) Donkey
d) Sheep
e) Cattle
d)
MCF virus is ovine herpes virus-2 (OvHV-2) and is carried by 95-99% of sheep in North America which show no symptoms. It is also carried by 75% of domestic goats, 40% of muskox, 37% of bighorn sheep, 25% of pronghorn antelope, 62% of mouflon sheep, and by a small percentage of elk, mule deer, and white tailed deer. Susceptible hosts include cattle, water buffalo, deer, pigs, and bison; bison are the most susceptible.
Which of these drugs is a neuromuscular blocker when given to a dog?
a) Neostigmine
d) Fentanyl
c) Atracurium
d) Naloxone
e) Edrophonium
c)
The correct answer is atracurium. Atracurium is a non-depolarizing neuromuscular blocker. Other neuromuscular blockers include pancuronium, d-tubocurarine and succinylcholine. Succinylcholine is a depolarizing neuromuscular blocker. Fentanyl is an opioid. Naloxone is an opioid antagonist. Edrophonium and neostigmine are cholinesterase inhibitors used to reverse neuromuscular blockers.
Several 16 to 20 month old Holstein dairy heifers who have been out in pasture have developed large areas of skin sloughing, which appears to affect mainly the white unpigmented areas (la peau lève et laisse des gales brunâtres sur les tissus sous-jacents). Based on this observation, what is the best diagnosis?
a) Allergic dermatitis
b) Ordinary sunburn
c) Malignant catarrhal fever, skin form
d) Insect hypersensitivity
e) Photosensitization
e)
Photosensitization mainly affects unpigmented skin where photodynamic agents have accumulated making the skin hyper-reactive to UV light. The cause of this photosensitization can be primary, in which case a plant-derived compound (such as hypericum) or chemical is injected, ingested or topically applied, is the cause. Alternatively, the cause can be secondary due to hepatic damage/failure where the liver fails to remove ingested chlorophyll-breakdown products like phylloerythrin, which accumulates in the skin and results in UV damage (sunburn). You need to determine whether this is primary or secondary by checking liver enzymes and bilirubin levels.
You are called one hot summer day to see a group of horses in New Mexico which are slobbering and not eating their hay. Three out of 20 horses seem to be visibly affected. On physical exam of the first one, you find fever of 104 F (40 C) and obvious oral ulcers, mainly on the tongue. What is your tentative diagnosis?
a) Bovine papular stomatitis
b) Foot-and-Mouth disease (FMD)
c) Glanders
d) Vesicular stomatitis
e) African Horse Sickness
d)
VS affects horses, cattle and pigs with similar clinical signs. It is a viral disease of high morbidity and low mortality that appears about every 7 to 10 years in the Southwestern United States. Yearly outbreaks occur in southern Mexico and northern South America. Black flies and midges appear to be the vectors. Affected premises should be quarantined.
A 1-year old female spayed Doberman Pinscher has presented after being hit by a car. Initial chest radiographs show mild contusions, and the patient appears to be otherwise stable. A right mid-shaft long oblique femoral fracture has been identified. Routine pre-operative blood work is unremarkable. A buccal mucosal bleeding test (BMBT) is elevated at 6 minutes. What will you administer prior to surgery?
a) Desmopressin acetate
b) Vitamin K
c) Whole blood transfusion
d) 1,25 dihydrocholecalciferol
a)
The correct answer is desmopressin acetate (DDAVP). Administration of desmopressin results in release of von Willebrand factor, which will help this patient with clotting. Given this dog’s breed and elevated BMBT there is a very strong likelihood she is afflicted with von Willebrand’s disease. In Dobermans this results in an inability to form a clot. This can be life threatening if the dog is taken to surgery.
A whole blood transfusion does not provide an adequate source of von Willebrand factor but may be necessary if the patient’s bleeding cannot be controlled despite appropriate pre-operative measures. 1,25 dihydrocholecalciferol is the active form of vitamin D which aids intestinal resorption of calcium. The BMBT does not assess factors 2, 7, 9, or 10 and therefore vitamin K is not indicated.
A goose was found weak on the shore of a local pond where oil had been dumped. The goose was covered in oil, dehydrated and weak but responsive. Which of the following is an important acute clinical effect of oil on affected birds?
a) Nephrotoxicity
b) Hepatotoxicity
c) Disruption of function of the plumage
d) Contact dermatitis
e) Lead toxicity
c)
Feathers serve a critical waterproofing and insulatory function which is disrupted by oil and can rapidly result in hypothermia. Other concerns for oiled birds include GI irritation from ingestion of oil during preening, hemolytic anemia, and pneumonia due to inhalation of oil.
Treatments include heat, supportive care, and activated charcoal. Once stabilized, frequent high pressure, warm, mild detergent baths and clean warm water rinses until water beads freely off of the feathers is important. Birds should be placed in warm air flow until dry and they should be maintained on self-skimming ponds for several days after washing to ensure full waterproofing.
Which infectious agent causes the clinical presentation of pigs most similar to Haemophilus parasuis (Glasser’s disease)?
a) Streptococcus suis
b) Erysipelothrix rhusiopathiae
c) Fusobacterium necrophorum
d) Mycoplasma hyosynoviae
A)
The correct answer is Streptococcus suis. Streptococcus suis and H. parasuis both cause polyarthritis, polyserositis, fever, and pneumonia in young piglets up to several weeks of age. Both can cause fibrinopurulent inflammation as well as meningitis and convulsions.
Erysipelas and M. hyosynoviae typically occur in grower and finisher pigs and do not result in pneumonia. Diamond-shaped skin lesions (thus the name “diamond skin disease”) are pathognomonic for Erysipelas. Fusobacterium necrophorum causes lameness via footrot or laminitis.
Once infected, for what period of time is canine parvovirus usually shed?
a) 2-3 months
b) 5-6 months
c) 3-4 weeks
d) 7-10 days
d)
The correct answer is 7-10 days. Canine parvovirus mainly affects puppies and young dogs less than a year of age. Transmission of the virus is through contact with infected feces and fomites such as hands, toys, the dog’s hair coat. The virus is very resilient in the environment and is resistant to many types of disinfectants. It replicates in the crypt epithelium of the gut and causes epithelial necrosis and hemorrhagic diarrhea. The virus can also affect the heart of young puppies, causing myocarditis. This occurs less commonly now since most bitches are immunized against the virus, which allows for maternal antibodies to protect young puppies from this form of the disease.
If a mass appears in the lungs on a right lateral radiograph but not on a left lateral radiograph, where is the mass located?
a) Body wall
b) Right lung
c) Mediastinum
d) Left lung
d)
The correct answer is left lung. On a right lateral radiograph, the right side is down. In this situation, the right lung lobes are compressed and the left lung lobes inflated, accentuating a mass in the left lung. On a left lateral radiograph, the left lobes are compressed and a mass in the left lung can be concealed due to compression of the lung surrounding the mass.
A 10 year male castrated German Shepherd dog presents for an acute onset of ptosis, drooping of the lip, and drooping of the cheek all on the left side. What nerve has been damaged?
a) CN VI
b) CN V
c) CN III
d) CN VII
d)
The correct answer is CN VII. This is the facial nerve which is responsible for motor of the facial muscles as well as sensation in the ear and lacrimation. CN V is mostly responsible for sensation. CN III is the oculomotor nerve and serves in movement of the eye. CN VI is also involved in movement of the ey
You have a 6-kg cat that you wish to raise his PCV from 15 to 25%. You plan to administer packed red blood cells. How many milliliters of packed red blood cells will this cat need?
a) 60 ml
b) 120 ml
c) 30 ml
d) 15 ml
a)
The correct answer is 60 ml. In order to raise the PCV 1% you will need to give 1ml/kg of packed red blood cells. So it takes 6mls to raise this cat’s PCV by 1%. If we are going to increase it by 10% we will need 60ml of packed red blood cells.
You are called to examine and treat a valuable 3 year old show cow that appeared normal yesterday but has collapsed and is too weak to get up. You examine her and find T=102F or 38.9 C, HR=130, and RR=42. Her heart is pounding very loudly. The mucous membranes of her eyes, mouth and vulva are all very pale. You diagnose an acutely bleeding abomasal ulcer. What is the most important treatment?
a) 20 liters of 1.3% sodium bicarbonate IV
b) 40 liters balanced electrolytes orally
c) 4 to 8 liters of fresh whole blood IV
d) 4 liters of commercial plasma IV plus vitamin K
e) 40 liters of saline IV
c)
In the case of an acute blood loss such as this, the most important treatment is whole blood. Other sodium-containing fluids may be beneficial while the blood is being collected if this will not result in losing time in getting the whole blood into this cow. In most cases the single blood transfusion results in recovery. After about 24 hours the cow will exhibit melena as the digested blood reaches the rectum.
A one-month old foal develops fever, icterus, and diarrhea acutely. Bloodwork shows hyperfibrinogenemia, hypoglycemia, and elevated liver enzymes. Which of these conditions is most likely?
a) Herpesviral hepatitis
b) Tyzzer’s disease
c) Clostridium novyi type B
d) Theiler’s disease
b)
The correct answer is Tyzzer’s disease. This is the most likely cause because of the age of the foal and the acute nature of the disease. Tyzzer’s disease is caused by Clostridium piliformis, which causes an acute necrotizing hepatitis. It affects only foals from about 1-6 weeks of age. Theiler’s disease is a condition of adult horses. Clostridium novyi is rare in horses and seen much more in sheep and cattle. Herpesvirus can cause hepatitis but is usually seen at or very soon after birth.
An 11-year old female Pomeranian presents to you for coughing and exercise intolerance. On exam: Wt: 9.25 lbs, T: 101.2F (38.4 C), HR: 132 bpm, RR: Panting, mucous membranes are pink. She has mild tracheal sensitivity and a grade III-IV/VI left apical holosystolic murmur and grade II/VI right apical holosystolic murmur. Femoral pulses are strong and synchronous, with a regular rhythm. She has harsh lung sounds bilaterally. On abdominal palpation, you note hepatomegaly. You find bilateral luxating patellas. You take chest radiographs (coeur élargi dans les radiographies latérales et dorsoventrales) and decide to treat the dog based on these findings. Which medication plan is most appropriate?
a) Clavamox and enrofloxacin
b) Oxygen and atenolol
c) Furosemide and enalapril
d) Atropine and a temporary pacemaker
e) Immiticide (Melarsomine)
c)
The radiograph here shows a severe symmetrical alveolar pattern in the perihilar region extending to the right and left caudal lung lobes. The heart is tall on the lateral view causing dorsal elevation of the trachea.
This, in conjunction with the physical findings, is compatible with left congestive heart failure (CHF) secondary to mitral valve regurgitation. The dog also has hepatic congestion evident by enlargement on the radiograph. Treatment for CHF include diuretics (furosemide/Lasix, hydrochlorothiazide, spironolactone), arterial vasodilators (enalapril, benazepril, amlodipine, hydralazine), positive inotropes (pimobendan), and venodilators (nitroglycerine).
Clavamox and enrofloxacin are antibiotics which could be used to treat pneumonia, but that is not this dog’s problem. Immiticide is the treatment for heartworm. Atenolol is a beta blocker and not part of the management of mitral regurgitation or CHF. Atropine or a pacemaker would be indicated for conduction problems.
A 6-month old cat presents for having ptyalism and for being underweight. On physical examination, you note a bright copper color to the cat’s iris bilaterally. What is this suggestive of?
a) Polycystic kidney disease
b) Portal systemic shunt
c) Toxoplasmosis
d) Hemolytic anemia
b)
The correct answer is a portal-systemic shunt. Ptyalism is a sign commonly seen with PSS in cats but not dogs, and the copper-colored iris is a striking and almost pathognomonic finding in conjunction with other clinical findings. Hemolytic anemia could cause icterus but not the change in iris color. Animals with polycystic kidney disease would not have a copper-colored iris. Toxoplasma can cause ocular signs such as uveitis but would not have a copper iris.
Which of these are used in the minor cross match for blood products when looking for a compatible blood donor for a dog?
a) Donor red blood cells, donor plasma
b) Recipient red blood cells, donor plasma
c) Recipient red blood cells, recipient plasma
d) Donor red blood cells, recipient plasma
b)
The correct answer is recipient red blood cells, donor plasma. In a minor crossmatch, you are looking to see if the factors in the plasma of the donor are going to react to the recipient’s red blood cells.
A 6-year old male neutered Weimaraner presents for left forelimb lameness. Radiographs show a mixed productive and destructive lesion affecting the left distal radius with accompanying soft tissue swelling. The lesion does not cross the joint. What is the most common primary bone tumor in the dog?
a) Multiple myeloma
b) Fibrosarcoma
c) Chondrosarcoma
d) Osteosarcoma
e) Hemangiosarcoma
d)
The correct answer is osteosarcoma. Chondrosarcoma, fibrosarcoma and hemangiosarcoma can all be primary bone tumors but are much less common in dogs than osteosarcoma
Which of these nerve blocks is used to examine the eyes of a horse?
a) Oculomotor nerve block
b) Auriculopalpebral nerve block
c) Corneal nerve block
d) Trigeminal nerve block
b)
The correct answer is auriculopalpebral nerve block. Blocking this branch of cranial nerve VII (facial nerve) disrupts the motor innervation to the orbicularis oculi, which is the muscle that closes the eye. In the horse, this muscle is very strong and can prevent a thorough ocular exam. To perform this block, lidocaine is injected subcutaneously at the caudal aspect of the zygomatic arch where the nerve is palpable. Because this is a motor nerve, the eye will not be able to close as well, but there is no anesthesia of the tissue.
A horse presents to you with a corneal ulcer. You are concerned because it appears to be infected. You perform cytology and find gram negative rods. What is the most likely organism infecting the corneal ulcer in this horse?
a) Staphylococcus spp.
b) Pasteurella multocida
c) Pseudomonas
d) E. coli
c)
The correct answer is Pseudomonas. Pseudomonas is the most common agent causing bacterial keratitis in the horse. The gram negative cytology provides further evidence that it is the likely culprit. Staphylococcus can cause keratitis in horses but is gram positive. E. coli and Pasteurella are not agents that are commonly involved with keratitis in the horse.
A 10-year old male castrated cat that you have previously diagnosed with hyperthyroidism presents to you for acute onset of blindness. You perform an ophthalmic exam and note retinal hemorrhage. What diagnostic test should you perform first?
a) Serum BUN and creatinine
b) Coagulation times
c) Total T4 levels
d) Free T4 levels by equilibrium dialysis
e) Blood pressure
e)
The correct answer is blood pressure. Cats with hyperthyroidism are likely to develop hypertension. If this is severe enough (>180-200 mmHg systolic), they can be at risk for acute retinal detachment or hemorrhage resulting in blindness. Prompt resolution of the hypertension is critical to prevent further damage to the eye and other organs.
A 6-year old female spayed English Pointer presents for lethargy and weight gain. The owner notes that the dog is eating and drinking a normal amount, but the dog is still gaining weight. A physical exam reveals weak pelvic limbs, facial nerve paralysis, a symmetrically patchy haircoat, and seborrhea. Lab work reveals a normocytic, normochromic anemia with a PCV of 29% (35-57%), lipemic serum, and cholesterol of 1090 mg/dl (135-278 mg/dl). What is the most likely diagnosis?
a) Adrenal dependent hyperadrenocorticism
b) Pituitary dependent hyperadrenocorticism
c) Hyperthyroidism
d) Hypothyroidism
d)
The correct answer is hypothyroidism. The clinical signs, physical exam findings, and lab work abnormalities are classical for hypothyroidism. Other common abnormalities seen with hypothyroidism include pyoderma, neuromuscular signs (ataxia, knuckling, vestibular signs, etc), markedly elevated triglycerides, and a mild normocytic, normochromic anemia. Hyperthyroidism rarely occurs in dogs. You would expect to see polyuria, polydipsia, and polyphagia with hyperadrenocorticism.
You are visiting a small “back-yard” flock of chickens and examining the animals. You find several small gray-red mites (approx 0.7 mm) on several of the chickens which you recognize as Dermanyssus gallinae and Ornithonyssus sylviarum. How are these mites best controlled?
a) Control of both Dermanyssus gallinae and Ornithonyssus sylviarum relies on thorough insecticidal treatment of the environment
b) Dermanyssus gallinae is controlled primarily by thorough insecticidal treatment of the environment and Ornithonyssus sylviarum must be controlled by application of approved pesticides to affected birds
c) ) Control of both Ornithonyssus sylviarum and Dermanyssus gallinae relies on application of approved pesticides to affected birds
d) Ornithonyssus sylviarum is controlled primarily by thorough insecticidal treatment of the environment and Dermanyssus gallinae must be controlled by application of approved pesticides to affected birds
b) Dermanyssus gallinae (the common red mite) maintains the majority of the population in the environment so it is important to monitor and treat the environment including the cracks and crevices where mites tend to reside. Ornithonyssus sylviarum mites (northern fowl mites) spend their entire life cycle on the bird. This allows them to multiply more rapidly and makes it essential to treat the birds themselves to control the problem.
Which of these is an adrenergic vasopressor in dogs?
a) Dopamine
b) Hydralazine
c) Atropine
d) Glycopyrrolate
a)
The correct answer is dopamine. Adrenergic vasopressors are frequently used to treat hypotension during anesthesia. Drugs in this category are dopamine, dobutamine, ephedrine, phenylephrine, and norepinephrine. Atropine and glycopyrrolate are anticholinergic drugs. Hydralazine is a vasodilator used to treat hypertension.
Several litters of 2 to 3 day old pigs have recently died rapidly with hemorrhagic enteritis. Post mortem lesions include mucosal hemorrhage, necrosis and emphysema in the small intestines. What pathogen is most likely to cause these signs?
a) Erysipelothrix rhusiopathiae
b) Clostridium perfringens type C
c) Haemophilus parasuis
d) Enterotoxigenic E. coli
e) Salmonella choleraesuis
b)
The age of these affected pigs along with the rapid course of hemorrhagic and necrotic enteritis help you come to this conclusion. As with many Clostridial diseases, vaccination is the most effective means of control. Other important clostridial diseases of swine include C. perfringens type A, C. difficile, C. tetani, C. botulinum, C. novyi, C. septicum, and C. chauvoei.
A cat presents for lethargy, depression, and weakness. The cat can’t seem to lift his head . You recommend running a chemistry panel on the cat. What potential finding explains can explain the findings?
a) Low potassium
b) Low phosphorus
c) High urea nitrogen
d) High glucose
e) Low calcium
a)
The cat in the image is exhibiting cervical ventroflexion, which is a general sign of weakness. The most common cause for this presentation is hypokalemia (low potassium), which can be caused by a variety of reasons (such as chronic renal failure).
This weakness can also be caused by a number of different problems other than low potassium, including myasthenia gravis; polymyopathies caused by toxoplasmosis, immune-mediated disease, or hyperadrenocorticism; and neuropathies caused by organophosphate poisoning, thiamine deficiency, or botulism.
A 6-year old Friesian cow presents to you with a mass on the left mandible. The farmer reports that the mass has developed over the last several weeks and the cow has recently had some difficulty eating and lost weight. On examination, the mass is firm, immobile, and painful on manipulation. You note a thick discharge with small granular particles. Based on the most likely diagnosis, what should you tell the farmer?
a) Treatment with sodium iodide intravenously is likely curative but the cow’s milk and meat will not be suitable for human consumption for 120 days
b) Intravenous penicillins are likely to be effective
c) The most effective treatment is oral sodium iodide
d) Treatment is unlikely to be successful and the cow should be culled
d)
This is a case of Actinomyces bovis or “lumpy jaw”. The keys to the diagnosis are the firm mass that is immobile over the mandible. The presence of “sulfur granules” in the discharge is also a characteristic finding with this disease. Unfortunately, simply making the diagnosis is not sufficient to answer this question correctly. All of the answer choices are potential treatments for lumpy jaw but this represents a moderate to severe case which is unlikely to respond to treatment due to difficulty in achieving the necessary antibiotic concentration over a sustained period. Therefore, the best answer choice in this case is to cull the cow.
What is the most common neoplasia seen in the equine stomach?
a) Gastric adenocarcinoma
b) Mesothelioma
c) Squamous cell carcinoma
d) Lymphosarcoma
c)
The correct answer is squamous cell carcinoma.
An owner brings her 4-year old female Labrador Retriever to your clinic because she believes she might be pregnant. She does not remember when the dog’s last heat cycle was. The dog’s abdomen appears fairly distended and you take a lateral abdominal radiograph which is shown below. What would be the earliest time you would expect to be able to see fetal skeletons on abdominal radiographs in the dog?
a) 33 days gestation
b) 53 days gestation
c) 43 days gestation
d) 23 days gestation
c)
The correct answer is 43 days gestation. The fetal skeleton ossifies at 42-45 days in the dog and 35-39 in the cat.
In the dog, a mineralized fetus can usually be seen around 42-46 days. The scapula, humerus, and femur can be made out around 46-51 days. The ribs can be seen at 52-59 days. Teeth and toes can be seen at 58-63 days.
Which of these drugs has the greatest potential for causing acute renal failure in the horse?
a) Diphenhydramine
b) Oxytetracycline
c) Xylazine
d) Neomycin
e) Dexamethasone
d) The correct answer is neomycin. Aminoglycosides are one of the most common causes of renal tubular nephrosis and acute renal failure. Of the aminoglycosides, neomycin is probably the most nephrotoxic, followed by gentamicin, amikacin, and streptomycin. The other big class of nephrotoxic drugs is non-steroidal anti-inflammatory drugs.
A middle aged MN stray cat is left on the doorstep of your clinic. The cat has a large dry crusted area of alopecia over his nose. A skin scraping of the area is negative. The lesion fluoresces blue under Wood’s lamp examination. Which of the following would be the best treatment?
a) Lufenuron
b) Athlete’s foot cream (clotrimazole)
c) Povidone-iodine scrub
d) Full body lyme sulfur dip, itraconazole
e) Doxycycline
d)
This cat has a ringworm infection caused by Microsporum canis. This fungi fluoresces blue under a Wood’s lamp in 50% of cases.
The best treatment for ringworm infection would include a combination topical and oral therapy. Lyme sulfur dip or an antifungal shampoo containing miconazole would be acceptable. Oral antifungals such as itraconazole or fluconazole are most effective with the least side effects.
Povidone-iodine scrub has not been shown to be effective against ringworm.
Lufenuron is classified as an insect development inhibitor because of its ability to inhibit chitin synthesis, thus in the past has been said to have some effect against fungal infections. This has been debated and not widely supported as a treatment for ringworm.
Doxycycline is an antibiotic and would not be effective in treatment of fungal disease.
Athlete’s foot cream (clotrimazole) may have some effect at treating the lesion. Most over-the-counter creams such as this also include a steroid like betamethasone which would not be desired. Although this lesion appears to be localized to the nasal area, ringworm may also be subclinical and this cat may have infection elsewhere in the skin that is not grossly visible. Therefore, the best therapy is a combination of topical and oral.
A 6-year old West Highland White Terrier comes in to see you for the mucopurulent ocular discharge. A Schirmer tear test shows no tear production. What is the treatment of choice for chronic canine keratoconjunctivitis sicca?
a) Topical cyclosporine and a topical steroid
b) Systemic antibiotics and corticosteroids
c) Systemic cyclosporine and antibiotics
d) Topical cyclosporine and systemic corticosteroids
a)
The correct answer is topical cyclosporine and a topical steroid. The treatment of KCS is aimed at reducing immune destruction of the lacrimal glands. Topical cyclosporine (Optimmune) and a topical steroid (frequently in a triple antibiotic/steroid ointment) are the treatment of choice. You should be cautious using steroids in acute cases due to the risk of corneal ulceration.
A client brings the one-half inch grub (blanc) to you one spring day, telling you it emerged from a hole in the back of one of his prize show cattle. He wants to know what to treat his cattle with and when.
a) Ivermectin in early fall
b) Organophosphates in summer
c) Thiabendazole in early fall
d) Moxidectin now, in spring
e) Ivermectin in February
a)
This is a cattle warble called Hypoderma. The 2 species are H. bovis and H. lineatum. They undergo a long migration in tissues and only emerge from the back of the animal in spring. The crucial treatment time is early fall when larvae are just beginning to migrate in tissues. Organophosphates or one of the macrocyclic lactones (ivermectin, doramectin, eprinomectin or moxidectin) are effective.
A 1.5-year old Quarter Horse gelding is presented to you for symmetric ataxia, weakness, and spasticity of all limbs, but worse in the hind limbs. When walking, the horse frequently drags his toes and the hind limbs frequently interfere with one another. Based on the signalment, history and physical examination findings, which of the following is the most likely cause of these clinical signs?
a) Botulism
b) Cauda Equina Syndrome
c) Equine Degenerative Myeloencephalopathy (EDM)
d) Equine Motor Neuron Disease (EMND)
e) Equine Protozoal Myeloencephalitis (EPM)
c)
The horse in this question has clinical signs most consistent with EDM; cervical vertebral malformation (wobblers) is also a possibility, but was not provided as an answer. The cause of EDM is unknown, but this disease typically affects young horses (< 2-3 years of age; but older horses can develop disease). Clinical signs are a result of diffuse neuronal fiber degeneration of various portions of the central nervous system. This disease has been associated with low serum vitamin E concentrations, suggesting that oxidative damage may play a role in the development of disease.
EMND is typically associated with muscle tremors, shifting of weight while standing, muscle atrophy and recumbency. Botulism is associated with generalized muscle weakness. Cauda equina syndrome causes analgesia of the perineum. EPM can cause a range of clinical signs, but is typically with asymmetric neurologic deficits.
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?
a) Taenia taeniaformis, Praziquantel
b) Enterobius vermicularis, Fenbendazole
c) Giardia intestinalis, Fenbendazole
d) Cryptosporidium, Clindamycin
e) Tritrichomonas foetus, Ronidazole
f) Paragonimus kellicotti, Praziquantel
e)
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.
You are examining a 13-year old Standardbred brood mare 5 hours after parturition. You note that the placenta is still present in the reproductive tract of the mare. What is the most appropriate therapy?
a) Administer oxytocin (IM or IV) and lavage the uterus to facilitate removal
b) Do nothing; the placenta is not considered retained until 12 hours post-parturition and it will likely be expelled by this time
c) Administer penicillin (IM) until the placenta is expelled on its own
d) Place physical traction on the placenta and remove it manually
a)
Most texts state that the placenta in a mare is retained after greater than 3 hours post-parturition; therefore, this would be considered a retained placenta. Oxytocin, along with uterine lavage, will cause the uterus to contract and facilitate expulsion of the placenta. Strong physical traction on the retained placenta is generally considered contraindicated, as you may tear the placenta and leave remnants of it within the uterus, resulting in possible complications. Broad-spectrum antimicrobials are often administered to decrease the incidence of metritis but alone would not be appropriate.
You are called out to examine a 4-year old dromedary who was castrated 10-days ago and is now not eating. The groin and prepucial area is extremely swollen. The camel is unable to stand and is drooling. His neck is extended and he appears to be unable to swallow. Which of the following is most likely responsible for these symptoms?
a) Rabies virus
b) Trypanosoma evansi
c) Clostridium tetani
d) Methicillin-resistant Staphylococcus aureus
c)
This camel is showing signs of tetanus. The organism was likely introduced into the body through the castration wound. It is recommended that camels are vaccinated against tetanus prior to castration. Reference: Trop Anim Health Prod. 2004 Apr;36(3):217-24.
While rabies may cause paralysis of the tongue and difficulty swallowing, the recent history of castration in this camel makes tetanus most likely.
Trypanosoma evansi is transmitted via biting flies and causes a slow wasting disease in camels.
A dog presents with acute onset vomiting, hemorrhagic diarrhea and fever. On fecal examination, you find many large fluke eggs. You question the owner and discover that the dog was recently in Oregon on a boating trip. What agent is most likely causing the clinical signs in this dog?
a) Neorickettsia helminthoeca
b) Oxytrema silicula
c) Nanophyetus salmincola
d) Rickettsia rickettsii
a)
The correct answer is Neorickettsia helminthoeca. This rickettsial organism is the causative agent of salmon poisoning. It is carried in the fluke, Nanophyetus salmincola, which requires the snail, Oxytrema silicula in its life cycle. The snail is what confines occurrence of salmon poisoning to the northwest coast.
Closure of the eyes is mediated by cranial nerve ____ and opening the eyes is mediated by CN ____.
a) V, III
b) III, VII
c) V, VII
d) VII, V
e) VII, III
e)
The answer is VII, III. Closure of the eyes is performed by the orbicularis oculi muscle innervated by the facial nerve. Opening of the eye is by the levator palpebrae superioris innervated by the oculomotor nerve. The trigeminal nerve supplies sensory innervation to the eye.
