Question of the day 3 Flashcards
A 2-year old female spayed Dachshund presents for further evaluation as a result of a mass on the pinna noted by the owner. On physical exam, the only abnormality noted was this mass. Cytology is consistent with a histiocytoma. Which of the following is the most reasonable treatment option?
A- Chemotherapy using lomustine
B- Radiation therapy
C- Benign Neglect
D- Cryotherapy
E- Radical surgical excision
C- Benign Neglect
Histiocytomas are typically benign and will often present as a small, raised mass that may or may not be ulcerated. Fortunately, these masses usually regress on their own, and surgical or medical intervention is typically not necessary.
An eight-year-old female Saint Bernard is presented with a six-week history of right pelvic limb lameness and swelling above the hock.
A radiograph of the affected limb is shown below. Three-view thoracic radiographs are unremarkable.
Based on the top differential, what is the treatment of choice?
A - Intralesional mitomycin D
B - Limb amputation
C - Intravenous cyclophosphamide
D - 6 - 8 weeks of oral clindamycin
E - Lipid complex amphotericin B IV
You examine a very ill 4-year old Holstein dairy cow on a large commercial dairy. She freshened one week ago and was producing well, until she was found down and unwilling to rise this morning when you were called. T=103F or 39.4 C, HR=90, and RR=35. The scleral vessels are dark are enlarged, her rumen is fairly empty and the motility is poor, and she appears too weak to rise. Rectal exam reveals an involuting uterus which can be retracted, discharging a brownish red mucoid non-odorous lochia through the vagina. The left rear quarter of her udder is swollen, hot, painful, and discolored (see image), and contains a serum-like secretion with clumps of fibrin in it. What is your diagnosis?
Metritis
Grain overload
Coliform mastitis
Hypocalcemia (milk fever)
Displaced abomasum
This is a case of severe acute coliform mastitis, and the absorbed endotoxin (LPS) is causing many of the systemic signs observed. The cow needs to be aggressively treated with IV fluids, NSAIDS, and supportive nursing. The gland should be frequently milked out. The use of both intramammary and systemic antimicrobial drugs to which most coliforms are susceptible is still controversial, but is often done in cows in a severe state of illness as in this case. While this cow may have secondary hypocalcemia, treatment with calcium needs to be approached cautiously, as endotoxic animals have very sensitive myocardium and arrest may occur if calcium is given IV. If given, preferred routes of calcium administration would be subcutaneous or oral.
A seven-year-old female chinchilla is presented with a history of anorexia and lethargy.
Which one of the following organs has the most prominent pathology in these radiographs?
(Click on radiographs to enlarge).
A - Stomach
B - Normal radiographs for a chinchilla
C - Uterus
D - Urinary bladder
E - Colon
uterus => pyomètre
A 36 hour foal born from a multiparous mare presents for weakness, decreased appetite, and tachycardia. On physical exam, you examine the sclera as seen in the photo. Based on the signalment and findings, what is a likely cause?
Neonatal Isoerythrolysis
Immune mediated thrombocytopenia
Congenital iron toxicity
Failure of passive transfer
Neonatal Isoerythrolysis (NI) would be a possible cause of the icterus noted in the sclera. NI is common in multiparous mares and usually affects foals between 24-72 hours of age. NI results in hemolysis, hyperbilirubinemia, and icterus. A low packed cell volume would further support NI.
NI develops because the newborn foal expresses alloantigens on its red blood cells inherited from the sire that the mare does not have. If the mare becomes sensitized to the sire’s specific antigen, maternal antibodies are produced and absorbed by the foal soon after birth. This subsequently results in lysis of the red blood cells.
These larvae shown below have been removed from the topline of beef cattle in the early winter.
Which one of the following treatments is the most appropriate in both lactating dairy and beef cattle?
A - Chloramphenicol
B - Pour-on moxidectin
C - Organophosphate spray
D - Rapid hand expulsion/squeezing
E - None. These are self-limiting
A 12-year old male neutered domestic short hair cat presents for ongoing evaluation of diabetes mellitus. The cat was diagnosed 6 months ago and has continued to be markedly polyuric, polydipsic, polyphagic, and has been gaining weight. The cat is currently receiving 10 units of glargine insulin every 12 hours. On physical exam, the cat weighs 15 pounds (6.8 kg) and has an enlarged head, abdomen, and paws. What imaging modality would be most appropriate to try and prove what you suspect is causing the uncontrolled diabetes and weight gain in this cat?
Magnetic resonance imaging (MRI) of the head
Radiographs of the thorax
Computed tomography (CT scan) of the abdomen
Ultrasound of the abdomen
Ultrasound of the neck
IRM => voir masse a/n du cerveau (acromégalie)
This cat has the signs and symptoms of acromegaly. Acromegaly is caused by excessive growth hormone release from the pars distalis from a tumor in the pituitary gland. Excessive growth hormone causes a defect in the insulin receptors on target cells causing insulin resistant diabetes mellitus. The enlarged head, paws, abdomen, and weight gain despite uncontrolled diabetes is due to the anabolic effects of the growth hormone.
Treatment for this condition includes radiation therapy to the pituitary tumor, high doses of insulin to try and control the diabetes, and somatostatin analogs (octreotide) to try and inhibit the release of growth hormone from the tumor. Surgical excision has been used as a form of treatment in people with pituitary tumors, but this has only been rarely reported in cats.
A four-month-old female mixed breed puppy is presented with a one-month history of generalized wobbliness when walking and head-bobbing when attempting to eat. The signs have not progressed.
Two MRI images are shown below.
What is the diagnosis?
A - Cerebellar hypoplasia
B - Lead toxicosis
C - Distemper encephalitis
D - Normal MRI
E - Chiari malformation
What is the primary mode of transmission of West Nile Virus (WNV) between birds?
Via mosquitoes
Via Cnemidocoptes mites
Via saliva
Via placenta
Via feces
Mosquito vectors are the primary mode of transmission for WNV between birds and other hosts (horses, humans). There are infrequent documented cases of the disease being spread by feces or saliva. No mites have been documented to transmit the disease. Birds do not have a placenta.
An intact male whippet presents with an acute onset of swelling and pain in one of his testicles.
A post-op image shown below.
Which one of the following tests is helpful to diagnose the cause of the swelling before surgery?
A - Magnetic resonance imaging
B - Lateral radiography
C - Positive contrast cystography
D - Nuclear scintigraphy scan
E - Ultrasonography
A 7-year old female spayed English Springer Spaniel presents for difficulty breathing and lethargy. Physical exam shows pale mucous membranes and increased respiratory effort. You collect blood for a complete blood count and a chemistry panel and you place a drop of blood with a drop of saline on a glass slide. After swirling the sample around, you can grossly see what is shown in the picture. What’s your diagnosis?
Vitamin K antagonist toxicity
Immune mediated hemolytic anemia
Hemolysis
Evan’s syndrome
Rouleaux formations
The image shows a positive slide agglutination test. The dark patches in the sample are caused by antibodies attached to the surface of the erythrocytes cross linking the cells together causing these clumps. This is highly suggestive of an immune mediated reaction to antigen on the individual’s red blood cells.
Rouleaux formations are red blood cells stacked together as a result of their natural discoid shape and large surface area causing them to have an affinity for each other. They typically resemble a stack of coins or cookies.
Evan’s syndrome is an autoimmune condition characterized by an immune attack on erythrocytes, platelets, and occasionally leukocytes as well. You would not be able to diagnose this on a slide agglutination test alone.
Vitamin K antagonist toxicity with rodenticide causes a coagulopathy but should not cause hemagglutination.
A herd of 25 Holstein heifers present with fever of 104-106°F (40-41.1°C) [N=100-102.5°F, 37.8-39.7°C], lethargy, and purulent nasal discharge.
They also have loud, harsh coughs.
Physical exam reveals crackles over the trachea, but not the lungs.
Fibrinonecrotic plaques are randomly dispersed over the nasal and ocular mucosa, but there are no oral ulcers.
Urine and feces appear normal.
Several affected heifers have an arched back and are straining because of a fibrinonecrotic vaginitis.
Which choice is the most important step to take next to evaluate and prevent this problem in the future?
A - Perform vaginal cultures for genital Campylobacter fetus venerealis
B - Evaluate breeding program; Consider 100% artificial insemination or use of Tritrichomonas foetus-negative bulls
C - Review infectious bovine rhinotracheitis (IBR) vaccination protocols
D - Test water for Leptospira serovars; Check feed for fecal contamination by dogs with Neospora caninum
E - Check for elevated mycotoxin levels in feed, particularly zearalonone due to Fusarium spp.
A 6-month old Chocolate Labrador presents for limping and failure to gain weight. He is housed in an outdoor kennel with other hunting dogs. He is fed a large breed dry puppy food. He received his puppy shots at 8, 12, and 16 weeks old. He is quiet, alert, and responsive. His body condition score is 3/9, with rib exposure and poor fat deposition. His mucous membranes are pale pink, with a capillary refill time of 2 seconds. His heart and lungs auscult normally. No abnormalities are felt on abdominal palpation. He is an intact male, and both testicles are descended. The only abnormalities are the pads of his two front feet and left hind foot (see image) that he chews at frequently. What is diagnostic test of choice?
Skin scraping
Fecal float
Biopsy
CBC and chemistry panel
PCV and TP
Radiographs
Hookworms (Ancylostoma and Uncinaria) are intestinal parasites that suck blood and can cause anemia, enteritis, coughing during larval migration, and dermatitis. Any young dog that is failing to thrive and/or has pale mucous membranes should be tested for intestinal parasites. Hookworm dermatitis, also called Ancylostomiasis is typically seen in conditions with poor sanitation and/or in kennels.
Hookworms can be transmitted in utero, during nursing, or via 3rd stage larva penetrating the skin. The most commonly affected skin areas are the pads and interdigital spaces of the feet, but can include any surface that contacts the ground. The larva migrate through the dog’s tissues before arriving in the intestines. They cause significant anemia, failure to thrive, or sudden death in young dogs. In mild cases, deworming protocols are often enough; with severe cases blood transfusions and parenteral treatments are often necessary.
Skin scraping and impression smears of the affected skin areas are typically unrewarding for isolating parasites. A PCV/TP would show signs of anemia, but not the underlying etiology. Complete blood cell count and chemistry will often show anemia that is regenerative and an eosinophilia. Radiographs would be unrewarding in this case. A biopsy may show migrating larva if biopsied soon after trauma, however this is not a diagnostic test routinely used.
Which type of immune reaction is occurring in this picture of a horse with limb edema secondary to a localized vasculitis?
A - Antigen-antibody complex disease (Type III)
B - Cell-mediated immune reactions (Type IV)
C - Immediate hypersensitivity and atopy (Type I)
D - Antibody-mediated cytotoxic reactions (Type II)
E - None of these
Vasculite = type 3
A 2-year old nonlactating dairy cow in California has a sudden onset of head tilt and drooling. The owner also reports that she appears less active and less interested in feed than normal, and today is circling in one direction in the pen. You examine her and find T=105F (40.6 C), HR=96, and RR=32. There is ptosis, drooped ear, and weakness of the lips on the affected side. You take a lumbosacral spinal tap (see photo), and submit the CSF to your lab. The results show elevated protein and WBCs, with the cell type being mainly monocytes. The lab reports seeing some gram positive bacteria in the monocytes of the CSF. Based on these findings what is the best treatment for this condition?
Penicillin
Metronidazole
Enrofloxacin
Metoclopramide
Chloramphenicol
DX = listériose
bactérie gram + => pénicilline
The diagnosis is Listeriosis. Listeria monocytogenes can effectively be treated in the early stages of the disease with penicillin, ampicillin, or tetracycline. Intramuscular procaine penicillin for example has a withdrawal of 10 days for slaughter (meat) and 48 hours for milk if the animal is lactating. Other choices of approved antimicrobials would also likely be effective since L. monocytogenes is susceptible to most antimicrobials. For a list of approved animal drugs see www.farad.org/vetgram. FARAD is the United States Food Animal Residue Avoidance Databank which gives withdrawal information as well as a list of prohibited drugs. The other drugs listed as choices here are prohibited and cannot be legally used in food animals in the USA.
A 15-year-old Quarter horse mare is presented for right front lameness grade 3/5 on the AAEP lameness scale (lameness consistently visible at the trot). She becomes sound after an abaxial nerve block.
Radiographs of the distal limb look are shown below.
What is the common name for the top differential diagnosis?
A - Pedal osteitis
B - High ringbone
C - Spavin
D - Exostosis of the second metacarpal
E - Chronic proliferative synovitis
A 2-year old mare presents to you several weeks after recovering from a mild upper respiratory infection. She now presents with edema and sloughing of the legs (see image), chest and abdomen as well as mucosal petechial hemorrhages. She is sore and reluctant to move. Biopsy of the skin lesion is consistent with aseptic necrotizing vasculitis. What is the most likely diagnosis?
Bastard strangles
Cantharidin toxicity
Type I hypersensitivity
Idiopathic thrombocytopenia
Purpura hemorrhagica
=> purpura hémorragique faisant suite à la gourme
This is the clinical and histologic appearance of purpura hemorrhagica. It is a type-III hypersensitivity which is when antigen-antibody complexes accumulate, leading to disease.
Purpura hemorrhagica most commonly occurs 2-4 weeks after exposure to certain infectious agents or vaccines. This condition is most commonly seen subsequent to infection with Streptococcus equi subsp. equi or vaccination against it but it can also be associated with other pathogens, particularly respiratory pathogens including other streptococcal species and equine influenza.
Regardless of the cause, purpura hemorrhagica results from accumulation of antigen-antibody complexes that deposit on blood vessel walls and activate a strong immune response (vasculitis). The leaky blood vessels lead to hemorrhage and edema.
Bastard strangles refers to the condition when Streptococcus equi subsp. equi creates abscesses in unusual sites (other than the lymph nodes draining the throat) such as abdominal or lung lymph nodes.
Cantharidin toxicity (also known as blister beetle toxicity) leads to mucosal irritation and results in colic and cystitis. It can also lead to hypocalcemia.
Primary immune-mediated thrombocytopenia (sometimes called idiopathic thrombocytopenia) can be seen in horses but is not consistent with the necrotizing vasculitis described in the case.
Type I hypersensitivity reactions are immediate reactions (such as urticaria) invoked by an antigen or allergen.
A two-year-old beagle is presented with patchy alopecia, papules, and thick crusts, on the ventral abdomen, chest, ears, and elbows.
The owner reports intense pruritus and a positive pinnal-pedal reflex is observed.
A flea comb does not reveal any fleas.
The image below shows what was discovered from a skin scraping.
Which one of the following organisms is depicted in the image?
A - Neotrombicula autumnalis
B - Demodex canis
C - Cheyletiella yasguri
D - Sarcoptes scabei
E - Straelensia cynotis
A 12-year-old male neutered West Highland White terrier is presented after he disappeared from home for six hours and returned with a left hind limb lameness.
Pelvic radiographs taken on presentation are shown below.
What is the most appropriate initial treatment?
A - Triple pelvic osteotomy
B - Femoral head and neck excision
C - Non-steroidal anti-inflammatory medication and rest
D - Closed reduction and Ehmer sling
E - Tibial tubercle transposition and Robert-Jones bandage
A 22-year-old Thoroughbred mare is presented for bilateral green nasal discharge, retching, coughing, and inappetence noted after feeding this evening.
The owner recently switched the mare to a pelleted diet because of the mare’s poor dentition.
Physical exam reveals bilateral green nasal discharge. The mucous membranes are pink and moist with a capillary refill time of 1.5 seconds.
A slight swelling is notable in the proximal-left jugular groove just caudal to the vertical ramus of the mandible.
Based on the most likely diagnosis, what initial therapy would be recommended?
Value Normal
100.6°F (38.1°C) 99.1–100.8°F (37.3–38.2°C)
HR=40 bpm 28-40 bpm
R=12 brpm 10-14 brpm
A - Withhold food and water; give sedatives and oxytocin; recheck in 2 hours
B - Ultrasound thorax, perform transtracheal wash for cytology and culture, begin broad-spectrum antimicrobials
C - Cautious guttural pouch endoscopy with lavage for Streptococcus equi spp. equi PCR, quarantine horse until results are available
D - Pass nasogastric tube; give atropine; lavage the esophagus until the obstruction clears
E - Administer antimicrobials, refer horse immediately for endoscopy and lavage under general anesthesia
A dog presents to your clinic with tenesmus and swelling near the anus as seen in the image. On examination, there is a fluctuant swelling lateral to the anus, and on rectal exam, you note lateral dilatation of the rectum. Which of the following is the most common signalment for dogs presenting with this problem?
There is no age or sex predilection
They are younger intact females
They are older intact males
They are older intact females
They are younger intact males
hernie périnéale => vieux chiens pas castrés
This is a case of a perineal hernia. Older intact male dogs are most commonly affected. Overrepresented breeds include Boxers, Collies, Kelpies, Pekingese, and Boston terriers. The hernia results from a weakened pelvic diaphragm. It is thought that there may be a hormonal component which results in weakening with time
Some farmed salmon appear lethargic with darkened skin and exophthalmia. Necropsy of one that died reveals vent hemorrhages and grayish granulomatous nodules on the kidneys.
Gram stain from the kidney lesion reveals the intracellular bacteria shown below.
How could this condition have been prevented?
A - Oxytetracycline in water; Cull fish older than 2 years
B - Treat females with erythromycin before spawning
C - Vaccinate all new arrivals
D - Test incoming fish with ELISA and use formalin for any positives
E - Increase water temp in tank/pond to 52-63 ºF (11-17°C); Supplement diet with vitamin C
A 3-year old female spayed indoor/outdoor domestic short hair presents for congestion and swelling over the bridge of the nose. The swelling over the nose is firm and seems to be subcutaneous. There is also mild enlargement of the mandibular lymph nodes. You perform cytology from a fine needle aspirate of the swelling over the nose and see narrow, budding, thick-walled yeasts surrounded by clear capsules (see picture). You also detected a lesion in the retina on fundic examination. Which of the following treatments would be indicated?
Amoxicillin-clavulanic acid
Doxycycline
Itraconazole
Lufenuron
Trimethoprim sulfa
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. Doxycycline, Trimethoprim sulfa, and Clavamox are all antibiotics and would not address a fungal infection. Lufenuron is a flea treatment that has had some implications for treatment of dermatophytes due to its ability to inhibit chitin. About 1/3 of the cell wall of a fungus is composed of chitin. This has not been a promising or approved treatment for ringworm and surely would not be an appropriate treatment for Cryptococcus.
A 12-week-old chicken from a young backyard flock is presented for evaluation because of weight loss, decreased appetite, and diarrhea.
The irises in the affected bird are lighter than normal with irregular pupillary margins, and the hen does not have a normal pupillary light reflex (bottom chicken in image). Several other young birds appear to be growing poorly compared to the rest of the flock.
Based on the presumptive diagnosis, how can this problem be prevented going forward?
A - Collect pharyngeal swabs from affected birds; Antibiotic Tx for entire flock based on culture and sensitivity
B - Cull birds from the same genetic line
C - Buy only vaccinated chicks
D - Use only mycoplasma-resistant bloodlines for new additions to flock
E - Isolate unaffected animals; Breed from survivors of disease
maladie de Marek => acheter des poulets vaccinés pour prévenir!
Rappel différence entre Marek et leucose lymphoïde aviaire :
Marek : lx extra-folliculaire (bourse) pcq affecte lymphocytes T, affecte poulets immatures sexuellement
Leucose : lx intra-folliculaire (bourse) pcq affecte lymphocytes B, affecte poulets matures sexuellement (c’est un rétrovirus donc c’est long pour qu’il intègre l’ADN)
The dog in the photograph was vaccinated earlier in the day. What type of allergic reaction is occurring?
Type IV
Type III
Type I
Type II
The correct answer is type I. Type I hypersensitivity is IgE-mediated and results in immune mediated hypersensitivity. Type II hypersensitivity is an antibody-dependent reaction and occurs due to IgG or IgM made against normal self antigens or some foreign antigen that resembles some molecule on the surface of host cells. Type III hypersensitivity is an immune complex-mediated reaction. This is caused when soluble antigen-antibody complexes form in large amounts and overwhelm the body instead of being normally removed by macrophages in the spleen and liver. Type IV is considered a delayed hypersensitivity and is cell-mediated. T8-lymphocytes will be sensitized to an antigen and differentiate into cytotoxic T-lymphocytes. T helper 1 type T4-lymphocytes become sensitized to an antigen and produce cytokines.
A ten-year-old female spayed Persian cat is presented for evaluation of a bleeding lump. There is a two-cm diameter, firm, solitary, hairless, dome-shaped, ulcerated mass on her left neck just behind the jaw that is bleeding.
Cytology obtained by fine needle aspirate reveals reveals cohesive clusters of large cells with round to oval nuclei that are tightly adherent to each other (see below).
Click the labwork icon to review hematology, blood chemistry and urinalysis test results.
Based on these findings, which choice is the most appropriate treatment option?
A - Immunotherapy, wide margin excision, chemotherapy
B - Cryosurgery, debridement, repeat in 3-5 weeks
C - Wide excision of mass, remove regional lymph node, prednisolone, radiotherapy
D - Debulk, intralesional implant chemotherapy, minimize sun and cigarette smoke exposure
E - Surgical removal
Several ornamental freshwater fish (Betta splendens) have recently developed a velvety, rust-colored appearance, especially around the eyes and gills (see below).
What is the appropriate treatment in pet fish for the presumptive diagnosis?
A - Tricaine methanesulfonate (MS222)
B - Chloroquine
C - Hydrogen peroxide
D - Potassium permanganate
E - None; this condition is self-limiting
A 9-month old male pitbull presents to you for hindlimb lameness that developed suddenly several days ago and has gotten worse. On your examination, the dog is painful on palpation of the left tibia. You take radiographs of the tibia which are shown below. Which of the following is the most appropriate treatment for the suspected condition?
Ampicillin
Carprofen
Splint stabilization
Fluconazole
Surgical correction
This is a case of panosteitis based on the young age of the patient and radiographic presence of focal intramedullary densities within the tibial diaphysis. Minor differentials could include osteomyelitis. Panosteitis is a self-limiting, painful condition characterized by limping and lameness. It typically affects the long bones of young dogs, usually between the ages of 5 to 18 months. It can occur with any breed, but it is more common in medium- to large-sized dog breeds.
Treatment is primarily supportive consisting of limiting activity and anti-inflammatory drugs. Therefore, carprofen is the best answer choice listed. Pain lasts from weeks to months and resolves in nearly all cases. While these treatments reduce the pain associated with the condition, they may not alter the duration or course of the disease.
Annotations:
Circled: There are focal areas of increased patchy medullary sclerosis in the distal femur and proximal tibia.
A 7-year old male castrated cat presents for respiratory distress with open-mouth breathing. You initially place him in oxygen and obtain thoracic radiographs when he is stabilized. The films are shown here. What is your diagnosis?
Left-sided congestive heart failure
Tracheal collapse
Pneumonia
Neoplasia
Feline asthma syndrome
The correct answer is left-sided congestive heart failure. The cardiac silhouette is tall suggestive of left ventricular enlargement, and there is an alveolar pattern in the lung fields. The pulmonary vasculature is also dilated. Remember that cats in heart failure can have edema distributed in patchy infiltrates throughout the lungs, in contrast to dogs where it is more typically in the perihilar region.
Asthma is less likely as no clear bronchial markings are seen and because of the infiltrate. Neoplasia is a consideration, but doesn’t explain the cardiac enlargement. Pneumonia could also cause this pattern of infiltrate (although it is more typically cranioventral), but also does not explain the cardiomegaly. There is no evidence of tracheal collapse, which is an exceedingly rare condition in the cat.
Annotations:
Orange: The cardiac silhouette is diffusely enlarged moderately
Yellow circle: Areas of alveolar pattern
Blue: pulmonary veins
Red: Pulmonary arteries. In this case there is enlargement of both the pulmonary arteries and veins
Green: pleural fissure line, most likely indicative of pleural effusion
A four-year-old Quarter horse is presented with a three-week history of diffuse patchy alopecia on the ventral midline and face, including a “bulls-eye” lesion in the center of the forehead.
There is a mild conjunctivitis and uveitis OU (both eyes). A punch skin biopsy looks like the image below.
What is the most appropriate treatment?
A - Trichlorfon drench, antibiotic ophthalmic ointment TID
B - Topical DMSO, oxybendazole every eight weeks
C - Do nothing
D - Corticosteriods, benzimidazole-piperazine every 12 weeks
E - Ivermectin now, repeat in four months
Half of the flock from a local broiler poultry farm has died in the last ten days.
Examination shows chickens that are gasping and coughing, extending their necks to inhale.
Some have blood-stained beaks. There are no obvious neurologic signs.
Necropsy finds hemorrhage in the airways, as shown below.
What is the most likely presumptive diagnosis?
A - Infectious coryza
B - Marek’s disease
C - Viscerotropic velogenic Newcastle disease
D - Infectious laryngotracheitis
E - Fowl pox, diphtheritic form
A four-month-old female mixed breed puppy is presented with a one-month history of generalized wobbliness when walking and head-bobbing when attempting to eat. The signs have not progressed.
Two MRI images are shown below.
What is the diagnosis?
A - Cerebellar hypoplasia
B - Lead toxicosis
C - Normal MRI
D - Distemper encephalitis
E - Chiari malformation
A five-year-old boxer is presented for routine vaccinations.
The owner points out a small, smooth mass on the right ear. Fine needle aspiration cytology is shown below.
Which one of the following choices is the most likely diagnosis?
A - Bacterial infection
B - Aural hematoma
C - Degranulating mast cell tumor
D - Lymphoma
E - Histiocytoma
A nine-year-old Quarterhorse mare is presented with a left hind limb lameness.
She tends to drag the left toe, and has a stabbing gait in that limb (adducts hindlimb, then suddenly abducts it just before the hoof hits the ground).
Hock flexion of the left hind significantly exacerbates the lameness for 5-6 strides. A radiograph of the hock is taken, shown below.
What is the common name for this problem?
A - Bone spavin
B - Tarsal hydrarthrosis
C - Splints
D - Osselets
E - Ringbone
A 9-year old male Queensland Heeler presents with a four day history of progressive tetraparesis. Physical exam showed him to be weakly ambulatory with support. As part of your initial workup, you take chest X-rays which are shown below. Which of the following next steps is the most appropriate test to confirm your clinical suspicion about the cause of the dog’s signs?
Myelogram
MRI of the brain
CT scan of the thorax
Bronchoalveolar lavage and culture
Tensilon response test
The correct answer is a Tensilon (edrophonium) response test. Hopefully, you were able to identify the mass in the cranial mediastinum on the chest radiograph, as this was one of the keys to this case. This, in conjunction with the dog’s other signs, are suggestive that this dog has a thymoma and associated secondary myasthenia gravis. Tensilon (edrophonium) is a rapidly acting anticholinesterase that reverses signs of myasthenia within minutes in most dogs.
A chest CT would be a valid test to confirm the presence of the mediastinal mass and might be an appropriate test before surgery but would not bring you closer to a diagnosis if you already have identified the mass. An MRI of the brain would assess a CNS cause of the dog’s signs, which are unlikely, given the other findings. Similarly, a myelogram would assess if a spinal cord lesion caused the dog’s signs, but the rest of the findings in this case should point you in a different direction.
Annotations:
Red arrow: the trachea is displaced dorsally due to the cranial mediastinal mass
Green circle: on the right lateral projection there is increased soft tissues in the ventral aspect of the thorax. The ventral aspect of the cardiac silhouette remains partially visible.
On the left lateral projection, there is also increased soft tissue opacity in the ventral aspect of the thorax. However on that projection the cardiac silhouette is not clearly visualized (purple circle). On both projections there is mild separation of the lung lobes indicating the concurrent pleural effusion (blue line)
On the VD the mass is highlighted in orange, the cardiac silhouette in pink. The cranial aspect of the cardiac silhouette is not clearly visualized due to “silhouetting”.
A rescued Pekin duck is presented for non-weight bearing lameness of the left pelvic limb and fever.
Which one of the following choices is the most likely diagnosis?
A - Panosteitis
B - Normal radiographs
C - Bumblefoot
D - Egg binding
E - Septic arthritis
