Incorrect/Trouble Area MCQ - Timed Exams Flashcards
Keratoconjunctivitis sicca, as seen in the image, comes from an abnormality in which of these structures?
A. Nasolacrimal ducts
B. Lacrimal gland and gland of the 3rd eyelid
C. Conjunctivat goblet cells
D. Meibomian gland
B
The correct answer is B.
KCS comes from a decrease of the aqueous portion of the tear film. This is produced by the lacrimal gland and the gland of the 3rd eyelid. Remember, there are three layers of the tear film:
(a) The mucous portion lies against the cornea and keeps the tear film adhered to it. This is made by conjunctival goblet cells.
(b) The aqueous portion has nutritional and immunologic factors and is in the middle. It is produced by the lacrimal gland and the gland of the 3rd eyelid.
(c) The lipid portion of the tear film is the most outer part, and it allows for even spreading and prevents evaporation of tears. It is produced by the meibomian glands.
When examining the eye of a 6-year old Labrador Retriever, you see the brown, round circular masses shown in the image free floating in the anterior chamber. What is the most likely diagnosis?
A. Ocular lymphoma
B. Uveal cyst
C. Uveal melanoma
D. Viral infection
B
The correct answer is B. This description is most consistent with a uveal cyst and not a melanoma because it is free-floating. It is often difficult to distinguish these two conditions because cysts can also be attached to the pupillary margin or posterior iris. The other way to try to distinguish the two is with transillumination. Melanomas will not transilluminate while many cysts will. Also, cysts are usually very spherical or ovoid and smooth while melanomas are usually fleshier-appearing masses.
You have been managing a 7-year old male Cocker Spaniel for immune-mediated hemolytic anemia and recurrent urinary tract infections with prednisone and trimethoprim sulfa antibiotics. He now presents to you for the ocular abnormalities visible in the photo. What test is most likely to confirm your tentative diagnosis?
A. Tonometry
B. Dilated fundic exam
C. Corneal biopsy
D. Pupillary light response
E. Schirmer tear test
E
The correct answer is E. This dog has a severe mucoid ocular discharge and corneal changes that are most consistent with keratoconjunctivitis sicca (dry eye). The history of TMS antibiotics is a likely etiology. The diagnostic test of choice for KCS is a Schirmer tear test. The other choices are not specific for the diagnosis of this condition.
Other causes of KCS in dogs and cats:
Dogs: Primary dacroadenitis, Distemper, TMS AB, trauma, hereditary.
Cats: Chronic FHV-1 scars conjunctiva –> KCS
Which of the following is most commonly caused by mast cell tumors of dogs?
A. Hypercalcemia of malignancy
B. Hyperviscosity syndrome
C. Seizures
D. Gastrointestinal uiceration
E. Thrombocytopathy
The release of histamine from mast cell granules causes hypersecretion of gastric acid via H2 receptors, predisposing them to Gl ulcers. H1 blockers, H2 blockers, and proton pump inhibitors are often prescribed for that reason.
Dr. Bates has just examined Flipper, a five-year-old male castrated English Springer Spaniel. Flipper has been presented for a wellness examination and vaccinations. The owner reported at the beginning of the visit that Flipper had been taking heartworm prevention, however today Flipper’s heartworm antigen test is positive. After further discussion, the owner admits that Flipper has missed several doses of heartworm prevention in the past year. Which of the following is the most appropriate option for initiating a conversation about heartworm disease in dogs?
A. Have you heard about heartworms before?
B. Do you know much about heartworms in dogs?
C. Are you familiar with heartworm disease in dogs?
D. What do you know about heartworms in dogs?
D
This is the most appropriate phrasing because the question is open-ended. The use of open-ended questions is encouraged to improve client communication. Open-ended questions allow the client to provide a comprehensive answer, which gives the most information to the medical team. All of the incorrect options feature closed questions. Questions beginning with “do,” “are,” and “have” are closed questions, or questions for which there is only one answer (yes or no). Closed questions limit the information the client is being invited to provide.
Next on your schedule is a 9-year-old, spayed female Domestic Longhair cat for “check lump.” The owner has brought her in today for evaluation of a 2.5cm mass in the region of the left caudal mammary gland. She just discovered the mass yesterday while grooming the cat. The mass is firm and fixed directly under the nipple. There is no nipple discharge, heat, or pain on palpation. Which of the following statements should you tell the owner?
A. In cats, the majority of mammary tumors are malignant, and a high percentage of these metastasize
B. Mammary gland surgery in cats is done by the simplest method that removes diseased tissue with clean margins
C. Once a cat develops one mammary tumor, they are usually stow to develop others
D. This cat is a good candidate for a lumpectomy since the mass is less than 5 cm in diameter and located directly under the nipple
E. Cytology is the primary diagnostic performed prior to surgery
The correct answer is the majority of mammary tumors are malignant, and a high percentage of these
In cats, 80% of mammary tumors are malignant, and the majority of these will metastasize. (In dogs, 50% of mammary tumors are malignant, and of those, approximately 50% will metastasize.) Therefore, all suspected or confirmed mammary tumors should be thoroughly staged with thoracic radiographs, abdominal ultrasound, and evaluation of peripheral lymph nodes following baseline CBC, blood chemistry, and urinalysis. Thus, relying solely on cytology to guide treatment is incorrect. Moreover, because feline mammary tumors are so highly malignant and metastatic, many cats rapidly develop additional tumors. The client should also be cautioned that once the patient is anesthetized and the surgical area is clipped, it is not uncommon to find additional tumors that were not palpable in the awake animal.
Because of the high rate of malignancy and metastasis, simply performing a lumpectomy is incorrect: all
mammary tissue should be removed in cats with mammary tumors. This is typically performed as a unilateral
mastectomy with removal of the contralateral mammary chain 2 to 4 weeks later. Lumpectomies are usually
reserved for dogs in whom masses are small and pellet-sized (less than 5mm in diameter), freely movable, and
not located directly under a nipple.
A 3-year-old neutered male Domestic Shorthair presents for multiple deep lacerations. The cat, which normally lives indoors, escaped last night and came home with wounds this morning. He is quiet, alert, and responsive with a temperature of 102.9°F. There are lacerations and some mild bruising across his trunk, but the remainder of his exam is unremarkable. You perform a complete blood cell count, serum biochemistry, and thoracic/abdominal radiographs, which do not reveal any abnormalities. You elect to anesthetize the cat for wound repair. Which of the following medications can be included in your anesthetic plan to provide pain relief for this cat?
A. Alfaxalone
B. Acepromazine
C. Midazolam
D. Diazepam
E. Ketamine
D
The best choice from the options given is ketamine, an MDA receptor antagonist. Inhibiting MDA receptors can decrease pain wind-up, decreasing this cat’s postoperative pain.
Acepromazine is a phenothiazine; it provides sedation, but no analgesia.
Alfaxalone is a water-soluble neuroanesthetic that has minimal to no analgesic properties.
Diazepam and midazolam are benzodiazepines, which are useful as anxiolytics, but not as analgesics.
While performing a routine dental cleaning on a 12-year-old cat, you notice a 1 cm sublingual soft tissue mass along the rostral mandible. Dental radiographs show bony destruction. You perform three-view thoracic radiographs while the cat is anesthetized, which do not reveal any evidence of metastasis. You then obtain a sample for biopsy and the cat is recovered uneventfully. When you receive histopathology results several days later, you learn that the cat has an oral squamous cell carcinoma. What do you tell the owner about her cat’s prognosis?
A. The prognosis is guarded; hemimandibulectomy may be considered but the 1-year survival rate is less than 50%
B. The prognosis is good; locat radiation is recommended to effectivety etiminate residual disease
C. The prognosis is fair; radiation and chemotherapy combined will result in a mean survival time of 3 years
D. The prognosis is exceltent; after surgical resection, the mass is not expected to recur
A
The most common malignant oral tumor in cats is squamous cell carcinoma (SCC). This tumor comprises nearly 80% of all feline oral tumors. Mandibular tumors are often associated with significant bony invasion. The treatment of choice is surgical resection, although it is not always feasible and it still carries a relatively poor outcome. In cats that are candidates for hemimandibulectomy, a one-year survival rate of 43% has been observed. Overall mean survival time for oral SCC is < 3 months. Neither chemotherapy nor radiation has been shown to offer significant benefit. NSAIDs may be used for palliative care.
A 2-year old indoor only male neutered domestic short haired cat presents for difficulty urinating. He is lethargic, weak, and vocalizing while frequently posturing to urinate. The owner states he has been doing this since last night, only passing a very tiny amount of urine. Which of the following fluids will you choose once his urethral obstruction is relieved?
A. Hetastarch
B. 0.9% Saline with 20 meq/L Potassium supplementation
C. 0.9% sodium chloride
D. Lactated ringers with 16 meq/L Potassium supplementation
C
The most common electrolyte disturbance from a urethral obstruction is hyperkalemia. This occurs from an impaired urinary excretion of potassium. This can cause life-threatening arrhythmias and needs to be quickly addressed, especially if potassium exceeds 7 mEq/L. 0.9% Sodium chloride is the fluid of choice to treat this disturbance. If this fluid is not available, then Lactated Ringer’s would be a good alternative due to the low potassium concentration in those fluids. In extreme cases, dextrose may need to be added to the fluids because this stimulates insulin secretion and helps to move the potassium intracellular. Sodium bicarbonate and calcium gluconate can also help this shift of potassium in extreme cases.
A two-year old, castrated male, outdoor mixed-breed cat presented because he would posture to urinate and could not pass urine. The owners reported that the cat had vomited yellow foam twice in the last 2 hours. He had not eaten since he fell from the top of the refrigerator about 12 hours ago. Physical examination revealed a temperature of 97.8 F (36.6 C), weak femoral pulses and HR 140 bpm. The cat was estimated to be 8% dehydrated. There was a large subcutanous hematoma throughout the inguinal and perineal area (see image). Urethral catheterization was unsuccessful. The urinary bladder was palpable, approximately half full with fluid. Radiographic examination of the abdomen found good abdominal contrast and a fluid-filled urinary bladder. Initial blood tests found:
BUN -120 mg/dl (19-34 mg/di)
Creatinine - 8.0 mg/dl (0.9-2.2 mg/dl)
K+ - 8.0 mEq/l (3.7-6.1 mEq/L)
Na+ - 145 mEq/l (146-156 mEq/L)
Venous blood gas: pH- 7.15 (7.25-7.4)
HCo3 - 12 mmHg (17-24 mmHg)
PCO2 - 45 mmHg (29-42 mmHg)
Which of the following additional diagnostic tests are all indicated?
A. Arterial blood pressure, urine culture, serum protein electrophoresis
B. Thoracic radiographs, blood glucose levels, thyroid hormone levels
C. Abdominal ultrasound, reticulocyte count, platelet count
D. Electrocardiogram, retrograde urethrogram, coagulation panel
E. Intravenous pyelogram, urinalysis, bile acids levels
D
The cat’s inability to urinate, severe azotemia, hyperkalemia and metabolic acidosis suggest a post-renal urinary tract obstruction. The retained urine in the bladder and unsuccessful catheterization as well as inguinal and perineal hematomas suggest urethral blockage or rupture rather than a bladder problem.
An electrocardiogram is indicated based on the cat’s hyperkalemia and bradycardia to assess for arrhythmias. If present, the cat could be treated with either calcium gluconate or with regular insulin followed by glucose.
Arterial blood pressure measurement is valid consideration as well.
A retrograde urethrogram with water soluble contrast media would outline a urethral stricture, rupture or blockage. If this does not reveal an abnormality, an intravenous pyelogram would highlight the urinary tract bilaterally. An ultrasound would direct further investigation into the kidneys, urinary bladder and other abdominal organs.
Assessment of the cat’s coagulation profile is indicated due to the skin hematoma.
There is no indication in the cat’s findings for a reticulocyte count, bile acids levels, thyroid hormone levels, or serum-protein electrophoresis
A 15 year old brood mare was frightened and reared over backward and hit herself on the poll of the head. What are the two most common bones that are likely to fracture in this type of injury?
A. Petrous temporal bone and stylohyoid bone B. Mandiote and maxilla
C. Talus and central tarsal bone
D. Basisphenoid and basioccipital
The correct answer is basisphenoid and basioccipital bones. The basioccipital fracture is thought to occur as a result of an avulsion fracture from the pull of the ventral straight muscle of the neck on its insertion point (basioccipital bone).
A 3 month old Arabian foal presents for a progressive onset of intention head tremors, ataxia, dysmetria, and spasticity. On physical exam, the foal is noted to have proper mentation and is not weak. Heart rate, respiratory rate, and temperature are within normal limits. Given the signalment and presentation, what is the most likely diagnosis?
A. Cerebellar dysplasia
B. Cerebellar abiotrophy
C. Inner ear disease
D. Sarcoeystis neurona
The correct answer is cerebellar abiotrophy. Cerebellar abiotrophy is usually observed in foals which are less than one year of age, particularly 1-6 months of age. Cerebellar abiotrophy is the most common cerebellar disease found in horses. It is mostly seen in Arabian, Oldenburg, and Gotland breeds. There is no treatment, and signs may be progressive. Diagnosis is based on a good history and clinical signs such as intention tremors, lack of a menace, hypermetria, and ataxia.
A 7-year old Arabian gelding is presented to you for clinical signs of fever and lethargy of 2 days duration along with signs of hind-limb ataxia and muscle fasciculations of the face and neck. The CBC and biochemistry profile are relatively normal and you decide to collect cerebrospinal fluid (CSF) from the lumbosacral space. Results of CSF analysis yields the following:
Color Clear
Total Protein 156 mg/dL (reference interval 50-80 mg/dL)
Total Nucleated Cell Count 40 cells/mcL (ref interval less than 5 cells/mcL)
Cytology Lymphocytic pleocytosis
Based on the clinical signs and CS analysis, which of the following is the most likely diagnosis and the most appropriate diagnostic test listed to confirm your diagnosis?
A. Cervical Vertebral Malformation (CVM); Myelography of the cervical spine
B. Equine Protozoal Myelitis (EPM); Western Blot of CSF
C. West Nile Encephalitis (WNV); Serum Immunoglobulin M (IgM) capture ELISA
D. Equine Herpes Virus (EHV) Myeloencephalitis; Virus isolation of buffy coat, nasal swab and/or CSF
E. Verminous encephalitis (Micronema deletrix); Culture of CSF
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.
An adult horse presents to you for multiple skin lesions. There are patchy areas of erythema, scaling, and alopecia along the ventral midline. There is a diamond-shaped lesion of erythema and scaling along the forehead. According to the owner, the lesions are not pruritic. What is the most likely cause of these lesions?
A. Habronema
B. Hypoderma
C. Haematobia
D. Onchocerca
E. Culicoides
The correct answer is Onchocerca. Onchocerca can cause dermatitis in the horse due to hypersensitivity to dying microfilariae. Lesions include alopecia and scaling of the ventral midline, face, and pectoral region. Often lesions are diamond shaped and there may be a “bull’s eye” lesion on top of the head. Onchocerca is nonseasonal, in contrast to culicoides hypersensitivity and variably pruritic. Ocular lesions can also occur with onchocerca including uveitis, conjunctivitis, and keratitis.
Culicoides hypersensitivity, also referred to as sweet itch, occurs due to allergy to the saliva of the gnat. It recurs seasonally in the warmer months and tends to worsen with age. Typically, horses are pruritic and develop lesions on the poll, mane, and tail from self trauma, although ventral midline dermatitis can occur as well. More chronically, scarring can occur. Treatment is to decrease exposure to the gnat and to treat with steroids.
Habronemiasis is a condition where the larvae of the stomach worm migrate and emerge creating granulomatous lesions, usually around the eye, male genitalia, or lower extremities. Inside the granulomas, you can find dead larvae.
Haematobia irritans is a bigger problem in cattle than horses (they reproduce in cow feces) but can affect horses, especially ones that are near cattle. It typically causes ventral midline dermatitis with wheals with a central crust that progress to alopecia and ulceration with fairly focal lesions, rather than more diffuse lesions caused by culicoides.
Lastly, Hypoderma is a bigger problem in cattle but can occur in horses and typically creates nodules on the back that have a pore on top.
A 3-year old mare is presented for multifocal, round, crusty lesions on her ventral abdomen, which are not particularly pruritic. The owner complains of an increased number of flies around the mare as well as the nearby cattle. What is the most likely diagnosis?
A. Sarcoptes scabei equi
B. Dermatophytosis
C. Culicoides hypersensitivity
D. Haemotobia irritans
The correct answer is Haematobia irritans. This fly is commonly known as the horn fly. It causes ventral midline dermatitis, as described in the question, on horses housed near cattle. They are often found around the horns, back, and sides of cattle on cooler days, and will affect the ventral abdomen on hot sunny days. Horn flies feed on blood and cause great economic losses in cattle. It can also serve as an intermediate host to Stephanofilaria stilesi, a filarial parasite that causes plaque lesions on the ventrum of cattle. Treatment and control of the flies is relatively easy with insecticide sprays, dust bags, or insecticide feed additives. Sarcoptes scabei infections and Culicoides hypersensitivity are extremely pruritic. Dermatophytosis is a good differential also, but Haematobia is a better choice, since the horses are affected by flies and are housed near cattle.
During a routine pre-purchase exam of a 5-year old Thoroughbred, many yellowish eggs are noted on the medial aspect of the cannon bone. Given the location of these eggs, what is the most likely diagnosis?
A.Flea eggs
B. Pinworm eggs
C. Horse bot eggs
D. Stomach worm eggs
The correct answer is horse bot eggs. Horse bots (Gasterophilus spp.) can lay their eggs anywhere. However, Gasterophilus intestinalis, which is the common bot, typically will lay their yellowish eggs on the medial aspect of the forelimb cannon bones.
Stomach worm (Habronema spp.) eggs are actually ingested by houseflies which are then ingested by horses.
Sometimes the infective larvae leave the fly as it is feeding around the lips of the horse and goes on to infect the horse. Pinworm (Oxyuris spp.) eggs are laid by gravid females around the perineum by cementing the eggs around the anus. Flea infestations are not typical in horses.
It is a rainy April and you are visiting a horse farm to evaluate a horse with itchy and flaky skin lesions on the pastern and mild lameness. On examination, you see an exudative seborrheic dermatitis of the plantar aspect of the pastern that is slightly malodorous. Which of the following is a term used to describe this condition in horses?
A. Sweet itch
B. Summer sores
C. Sweeney
D. Scratches
E. Ringbone
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.
What percentage of the kidney must be damaged in order to see laboratory changes consistent with renal insufficiency in horses?
A. 50%
B. 25%
C. 33%
D. 66%
E. 80%
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.
A new horse owner calls you and wants to know how to prevent calcium carbonate urolith formation in a horse. Which of the following promotes calcium carbonate urolith formation?
A. Maintaining an acidic urine pH
B. Maintaining an alkaline urine pH
C. Low urine specific gravity
D. Low amounts of mucoproteins
The correct answer is maintaining an alkaline urine. Calcium carbonate stones in horses have a higher likelihood of forming in alkaline urine. Mucoproteins in urine may serve as a nidus for stone formation but is not specific for calcium carbonate stones.
Which is recommended for initial treatment of a calf born with moderate flexural deformities of the distal forelimb?
A. Cut both superficial and deep flexor tendons
B. Apply external fixator using Steinman pins
C. Posterior half cast from just below carpus to ground
D. Full length leg cast from elbow to ground
C
Flexural deformities are usually caused by contracted flexor tendons. Mild to moderate cases often respond to splinting, and a great way to make a form fitting and safe splint is to make a posterior half cast. It is padded well underneath and attached with tape so it can be taken off to check for sores and adjusted as needed. A full length cast is not necessary in this case, needs to be changed every 2 to 3 weeks in a rapidly growing calf, is more expensive, and more likely to cause sores. Cutting tendons is a last resort. Applying Steinman pin fixator devices is invasive and more costly and unlikely to be as successful as other choices.
There are a number of drugs that are used extra label in beef cattle. When working with any food animal, you always have to consider milk and meat withdrawal. What is the meat withdrawal (in days) for xylazine, tolazoline, lidocaine, and meloxicam, respectively?
A. 15, 1, 8, 4
B. 3, 7, 3, 18
C. 7, 18, 21, 15
D. 4, 1, 18, 21
E. 4, 8, 4, 15
The correct answer is 4, 8, 4, and 15. Remember that xylazine is extremely potent in cattle, taking 10% of the dose that would be given to a horse of equivalent size is sufficient.
Tolazoline is an alpha 2 antagonist. Give the same volume as xylazine. Lidocaine is commonly used during c-sections in cattle. If a producer is doing a c-section as a salvage procedure, it is important to inform that person that the cow cannot go to slaughter for 4 days.
Meloxicam is being used more and more. It is longer acting (~ 4 days) than banamine, but banamine only has 4 days of meat withdrawal. If you plan on going into production medicine, it is important to memorize the numbers for these commonly used drugs so that you can inform the producer.
Ivermectin is ineffective against
A. Trematodes
B. Ticks
C. Nematodes
D. Mites
The correct answer is trematodes (flukes). Ivermectin has activity against ticks, mites, nematodes, and even lice.
Ivermectin works by stimulating GABA which is an inhibitory neurotransmitter.
A producer sold cattle interstate and is shipping them over state lines. The cattle being shipped must be tested for tuberculosis per interstate shipping regulations. After ensuring the animals are not receiving other medications, vaccinations, or anthelmintic drugs, you perform the test by injecting purified protein derivative tuberculin (PPD bovis) intradermally in the caudal fold of each animal and then return to the farm 48 hours later to read the result. One cow is exhibiting very mild thickening at the injection site. The rest of the herd shows no swelling, sensitivity, or increased skin thickness at the injection sites. What is the next best step?
A. Mild thickening of the caudal fold is an expected negative result. Clear the herd for shipment.
B. Wait another 24 hours and read the TB tests again.
C. Hold the cow exhibiting thickening to read again tomorrow, clear the rest of the herd for shipment in 24 hours.
D. Notify the state veterinarian of the test results and detain the entire herd
Bovine TB (tuberculosis) is a significant disease caused by the bacteria Mycobacterium bovis. The disease is regulated and is routinely tested for prior to interstate shipment. The TB test described is a delayed-type hypersensitivity reaction that occurs from a T cell response. Per the USDA APHIS, bovine TB tests must be read at 72 +/-6 hours. Therefore, the correct answer to this question is to wait another 24 hours and read the TB tests from all cows again.
If any cows are showing evidence of a positive result when read at 66-78 hours (72 is optimal), it is important to report immediately to both the Assistant District Director and the State Animal Health Official.
