2014 questions Flashcards
A 2-year old thoroughbred mare has a 1-month history of poor race performance. The mare slows down markedly near the end of races with labored breathing, excessive swallowing and a bilateral epistaxis which resolves with time. She coughs after exercise, but otherwise acts normally and has a good appetite.
With the horse calm and well rested, no obvious abnormalities are visible on endoscopic exam. A transtracheal wash shows the following image
What should the owner be told?
A - This may be a case of bastard strangles
B - The horse should improve on antihistamines
C - We need to biopsy for ethmoid hematoma
D - Prognosis is poor-suspect gastric ulcer reflux
E - This is a very common problem in thoroughbreds
E- This is very common problem in thoroughbreds
his is a classic description ofexercise-induced pulmonary hemorrhage (EIPH)-Very common (43-75% of flat racers). Hemorrhage from lungs possibly may occur in ALL Thoroughbreds.
Note that only ~ 10% of horses with EIPH may show epistaxis- look instead for a Hx of exercise intolerance.
On trans-tracheal wash (TTW) see alveolar macrophages containing hemosiderin (dark pigment granules left from phagoscytized RBCs). To maximize your chances of seeing blood in trachea, do endoscopy AFTER exercise.
Two other big rule outs for epistaxis are:
Hyperadrenocorticism is suspected in a 9-year old female spayed dog with a two-month history of increased appetite, thirst and urinary accidents.
Which of the following diagnostic test is most reliable when results are positive?
Urine Cortisol Creatinine Ratio (UCCR). Sensitivity=90% , Specificity =25%
ACTH Stimulation. Sensitivity=80% , Specificity =85%
Low Dose Dexamethasone Suppression. Sensitivity=95% , Specificity =50%
A - Low Dose Dexamethasone Suppression (LDDS)
B - ACTH Stimulation
C - Urine Cortisol Creatinine Ratio
D - Cannot say without knowing the positive predictive value
E - Cannot say without knowing the negative predictive value
B- ACTH stimulation
ACTH Stimulation. The two diagnostic screening tests used most commonly for diagnosis of hyperadrenocorticism are the ACTH stimulation test and the LDDS. Remember your Ps and Ns.
ACTH Stim is the most sPecific (fewer false Pos, so trust a POS test more).
LDDS is more seNsitive (fewer false Negs, so trust NEG test more).
Click here for a diagram
Either way, these 2 tests are useful to screen for Cushing’s, but a confirmatory test is usually required if you get a positive, to differentiate between a pituitary HAC or an adrenal HAC case [high-dose dexamethasone suppression test (HDDST) or ACTH concentration].
The Urine Cortisol Creatinine Ratio (UCCR) has a low specificity (~25%), which means high false positives. 75% of dogs with non-adrenal illness will have a UCCR result consistent with HAC.
So, a positive UCCR is not useful to identify HAC, however, a negative is very useful to rule-out HAC as dogs with a normal UCCR cannot have HAC.
A 6-year old male intact Great Dane presents with a 2-week history of difficulty rising and hindlimb lameness. He has been intermittently anorexic.
The dog is febrile, and displays kyphosis (hunched back), stiff gait and spinal pain over the T3-L3 region with neurologic deficits. CBC shows a hematocrit of 38%..[N=37-55%], WBC=17,500..[N=500.4-15,300], U/A shows pyuria.
On a lateral spinal radiograph irregular lysis crossing the vertebral end plates is visible with collapse of at least one disc space, suggesting a diagnosis of diskospondylitis.
What test is indicated?
A - Transtracheal wash
B - Chest radiographs, 3 views
C - Myelography
D - Brucella canis titers
E - Fungal culture, Aspergillus
D. Brucella canis titers
Brucella canis titers are indicated. Diskospondylitis is a vertebral infection from hematogenous spread of bacteria (or fungi) from another site. Typically seen middle-aged big breeds, especially German Shepherds, Great Danes.
Usually caused by hematogenous spread of STAPH AUREUS from primary infection elsewhere. See bacteremia, pyuria in 50%. Blood cultures positive in 75%.
Diskospondylitis can be caused by Brucella canis, and sexually intact animals with suspected diskospondylitis should have Brucella titers measured. Recurrence is common with B. canis.
Remember Brucella in horses with fistulous withers too- do serum agglutination titer for Brucella abortus, ESPECIALLY when horse has had contact with cattle.
An alpaca is presented in poor body condition with an unkempt coat, patchy alopecia and severe pruritis and crusting of the extremities. A photo of an affected limb is shown below.
What is the most appropriate diagnostic step?http://www.merckmanuals.com/vet/zk/multimedia/v4734770/n/x.html
A - Tell Yoda you found his brother
B - Test skin crusts for contagious ecthyma parapoxviruses
C - Check thyroid status and bluetongue titers
D - Punch biopsy
E - Skin scraping and microscopic exam
Like most other species, South American camelidsget sarcoptic mange (scabies). A skin scrape and microscopic exam can rapidly confirm the diagnosis. Treatment is an avermectin-family drug, SQ every 2 weeks. One report suggests amitraz is also effective.
If you see a severely pruritic dog that looks like this, think of canine sarcoptic mange.
If you see a severely pruritic cow that looks like this, think of bovine sarcoptic mange.
In contrast, some things may look like mange, but aren’t. The dog in this image is NOT pruritic, he is severely affected with dermatophytosis (ringworm). A skin scrape will help tell you the difference.
An outbreak of diarrheal disease of piglets has occurred which affected the healthiest animals in the herd, 1-2 weeks after weaning.
Some affected piglets had no signs except peracute death. Other affected piglets exhibit diarrhea, ataxia, paralysis, and recumbency.
What condition is at the top of the differential diagnosis list?
A - Clostridium perfringens type C enteritis
B - Edema disease
C - Porcine proliferative enteritis
D - Epidemic transmissible gastroenteritis (TGE)
E - Hemagglutinating encephalomyelitis virus (HEV)
B Edema disease
Edema disease is caused by entertoxigenic E. coli (ETEC). Look for severe acute illness ranging from peracute death with no signs to CNS involvement with ataxia, paralysis, and recumbency in healthiest pigs 1-2 weeks after weaning.
Hemagglutinating encephalomyelitis virus (HEV), is almost exclusive to piglets less than 4 weeks old. Two clinical presentations: Vomiting and wasting disease (VWD) and encephalitic.
Clostridium perfringens type C enteritis ,also called enterotoxemia in other species is characterized by a HEMORRHAGIC diarrhea in 1-3 day old piglets.
Porcine proliferative enteritis is principally a diarrheal disease of growing finishing (40- to 80-lb) pigs and young breeding pigs.
Epidemic transmissible gastroenteritis (TGE) in non-immune pig herds characterized by HIGH MORBIDITY and HIGH MORTALITY in piglets less than 1 week old.
A group of 2 1/2 month old feeder pigs are presented with non-pruritic keratinized skin lesions and mild lethargy. One severely affected animal is depressed and anorexic.
Click here to see image 1
Click here to see image 2
What treatment is most appropriate for the presumptive diagnosis?
A - Supplement dietary zinc
B - High dose trimethoprim-sulfonamide 7-10 days
C - Copper sulphate bath or sprays
D - Ivermectin SQ now, repeat in 2 weeks
E - Spray with malathion (0.05%)
A supplement dietary zinc
n pigs, zinc deficiency causes parakeratosis. Zinc supplementation will resolve clinical signs.
Starter diets should contain 125 ppm zinc (and 0.9% calcium)
Grower diets should contain 75 ppm zinc (and 0.60-0.65% calcium)
Finisher diets should contain 50 ppm zinc (and 0.45 to 0.50% calcium)
Parakeratosis may resemble exudative dermatitis (“greasy pig disease”), caused by Staphylococcus hyicus. Exudative dermatitis is more typically seen in younger suckling piglets and treated with antibiotics.
Sarcoptic mange (Sarcoptes scabiei var suis) is typically pruritic and treated with antiparasitics like ivermectin or pigs may be sprayed with lindane (0.05-0.1%) or malathion (0.05%).
A 3-year old male neutered Labrador retriever from the Ohio river valley basin is presented with chronic large bowel diarrhea and signs of respiratory disease (cough, fever).
A lymph node smear shows round to ovoid (1-4 micrometers) encapsulated structures inside macrophages and giant cells. The organisms have thin cell walls, with thin clear zone between cell wall and cytoplasm.
What is the diagnosis?
A - Histoplasmosis
B - Coccidioidomycosis
C - Blastomycosis
D - Cryptococcosis
E - Aspergillosis
Think of Histoplasmosis in a dog with these findings (possible respiratory and diarrheal fungal disease, with tiny organisms in macrophages).
Histoplasmosis is seen in the river valleys of the central United States, associated with bird and bat droppings in soil.
The big DDX is blastomycosis, also seen in the same area, with a respiratory presentation. Histo is more a chronic diarrheal and respiratory disease in dogs and a respiratory disease in cats.
Note that histoplasma organisms are much smaller (1-4 micrometer for histo vs. 8-25 micrometers for blasto), and UNLIKE blasto, histoplasma organisms are difficult to detect with routine H&E stain.
Use PAS, Gomoris methenamine silver or Gridley’s fungal stains to see yeast forms in macrophages and giant cells(round to ovoid structures(1-4 micrometers), thin cell wall, thin, clear zone between cell wall and cytoplasm.
Coccidioidomycosis is seen in the arid and semiarid Southwestern U.S., Mexico and Central America. Organisms vary in size (20-80 micrometers to 200 micrometers) spherules with a double-contoured wall.
Mature spherules (sporangia) contain tiny endospores (sporangiospores) 2-5 micrometers in diameter. THINK DUSTY DESERT. Spores are carried on dust and inhaled. Epidemics may occur after dust storms or excavation.
Because it is ubiquitous, positive culture results for aspergillus should be supported by demonstration of narrow, hyaline, septate, branching hyphae. Usually a nasal presentation in dogs.
Think of Cryptococcus in cats with a granulomatous rhinitis and sinusitis. This nasal cavity disease in cats sometimes causes a swollen “roman nose” appearance. Seen in other species as well (cows, dogs) but with varying presentations.
During the necropsy of an 8 year-old mixed breed dog from the Southern United States, reactive granulomas in the esophagus containing bright red worms, 40 mm to 70 mm long are found.
What is the diagnosis?
A - Ollulanus tricuspis
B - Haemonchus placei
C - Spirocerca lupi
D - Gastrophilus spp.
E - Physaloptera spp.
C. Spirocerca lupi
A disease of dogs in the Southern U.S. and tropical climates, Spirocerca lupi (esophageal worms) make reactive granulomas of variable size in the esophageal, gastric or aortic walls.
Spirocercosis may also lead to aneurysm in the thoracic aorta or an ossifying spondylitis of the posterior thoracic vertebrae.
Typically asymptomatic, but large granuloma can cause esophageal obstruction. Large granomas may become neoplastic (osteosarcoma, fibrosarcoma).
Some dogs develop spondylitis or enlargement of the extremities characteristic of hypertrophic osteopathy.
All four of the other choices are gastric parasites.
Ollulanus tricuspis is an uncommon gastric parasite of cats.
Physaloptera spp. is a stomach worm that may cause vomiting, anorexia, dark feces in dogs and cats.
Haemonchus spp., Ostertagia spp. and Trichostrongylus spp. are found in the abomasum of ruminants.
Gastrophilus spp. are the larvae of horse bot flies, found in the stomach of horses.
A 9 year-old male neutered domestic shorthair cat is presented with a 4 week history of occasional disorientation and bumping into things. The cat does not visually track a ball rolled in front of him and has decreased pupillary light reflexes OU.
On fundoscopic exam, the retinal vessels and disc are obscured by something in the way. (see image, below)
What testing is indicated to assess the two most common underlying causes of this condition in cats?
A - CSF analysis, CBC
B - Thyroid function, BUN/Creatinine
C - Adrenal function, Arterial pressure
D - Hepatic function, Serum globulins
E - Urinalysis, Pancreatic function, fasting blood glucose
B Thyroid function, BUN/creatinine
Thyroid function, BUN/Creatinine. This presentation of vision loss in an older cat suggests retinal detachment, typically secondary to HYPERTENSION.
Chronic renal disease may lead to HYPERtension and retinal detachment-Physical exam, history and BUN/creatinine will rule this disease in or out.
HYPERthyroidism can ALSO cause HYPERtension. Your physical exam and history, plus a measure of T4 will help you evaluate this condition.
Other diseases associated with retinal detachment include your alphabet diseases and 2 T’s:
FIP, FeLV, FIV
Toxoplasmosis and Trauma
Follow these links to see classic retinal detachment in a dog with renal disease and focal retinal detachment in a cat with cryptococcosis.
Remember you can see hemorrhage with retinal detachment, as in this example from a young dog with Collie-eye anomaly.
For comparison, see this example of another big retinal disease, Progressive retinal atrophy (PRA)- think of SLOW loss
A 4 month old filly is presented with a 4 day history of lethargy, heavy breathing, cough and decreased appetite.
T=104.9 F (40.5 C)..[N=99-101.3 F]
HR=72 bpm………….[N=28-40]
RR=44 brpm…………[N=10-14]
On lung auscultation asymmetrically-distributed crackles and wheezes are audible. Some areas have no breath sounds and a dull resonance on thoracic percussion. A lateral chest radiograph shows consolidated nodular lung lesions and mediastinal lymphadenopathy.
What is the treatment of choice?
A - Erythromycin and Rifampin
B - Chloramphenicol and Aminophylline
C - Vancomycin. Atropine if see bronchspasm
D - High dose procaine penicillin G after abcesses rupture
E - Thoracocentesis and Amikacin. Saline cathartic if see diarrhea
A. Erthromycin and Rifampin
Erythromycin and Rifampin. This is the clinical picture of a foal with pneumonia. In this case, a chest radiograph with consolidated nodular lung lesions and mediastinal lymphadenopathy is highly suggestive of Rhodococcus equi in a foal under 5 months of age. Treat long term 4 to 10 weeks with Erythromycin and Rifampin (expensive).
If a foal under 5 months with signs of pneumonia had diarrhea or gram positive pleomorphic rods (like Chinese letters) in a transtracheal wash, these signs would also suggest Rhodococcus.
Click hereto see an ultrasound video from Merck of a 3 month-old foal with rhodococcal pneumonia.
Click herefor examples of imaging of Rhodococcus lungs from the VetNext website.
A client is considering the purchase of a 12-year old prize-winning thoroughbred mare for breeding. The pathology report from an endometrial biopsy says the mare is category III by the Kenney scoring system.
What advice is most appropriate to give the client?
A - Don’t buy this mare for breeding
B - 10%-50% chance of bringing a foal to term
C - 80%-90% chance of bringing a foal to term
D - 50%-80 chance of bringing a foal to term
E - Best to breed by artificial insemination
A Don’t buy this mare for breeding
Don’t purchase a category III mare for breeding. Endometrial biopsy predicts a mare’s ability to carry a foal to term and category III is the worst news. (Remember “3 strikes and you are out”).
Endometrial biopsies are classified into 3 types by the Kenney system according to degree of periglandular uterine fibrosis and scarring. The Kenney system gives a % probability that a mare can carry a foal to term. Category I is best. Most horses fall in category II. Category III is worst.
Category I No changes
(80%-90%)
Category IIA Minor changes
(50%-80%)
Category IIB Moderate changes
(10%-50%)
Category III Severe changes.
Less than 10% probability can carry a foal to term.
During a routine dental cleaning under isoflurane anesthesia on an 8-year old male neutered Doberman, the ECG monitor shows the following pattern.
The dog is stable and doing fine. What is this pattern?
A - Atrial fibrillation
B - Ventricular premature complexes
C - Atrioventricular (AV) block
D - Accelerated idioventricular rhythm
E - Sinus arrhythmia
B Ventricular premature complexes
These are ventricular premature complexes(VPCs).
You had better be thinking the dog is in early stages of Dilated Cardiomyopathy (DCM).
According to Merck, 9th ed. “…ventricular premature contractions on a routine ECG in a presumed healthy DOBERMAN Pinscher or BOXER is HIGHLY SUGGESTIVE of CARDIOMYOPATHY”.
Echocardiography is the test of choice for definitive diagnosis of DCM.
Remember this mnemonic for DCM breed predispositions: “DCM in a BOX” (ie: “D_obes, C_ockers, M_assive dogs (giant breeds), in a BOX_er”
ALWAYS FATAL. Death usually in 6 to 24 months after Dx. WORSE Prognosis in DOBES, generally survive less than 6 months from Dx.
In which category of drugs are isoproterenol and dobutamine classified?
A - Beta adrenergic agonists
B - Angiotensin-converting enzyme (ACE) inhibitors
C - Phosphodiesterase (PDE) inhibitors
D - Calcium channel blockers
E - Negative chronotropes
A Beta adrenergic agonists
Isoproteronol and dobutamine are beta adrenergic agonists and positive inotropes (increase cardiac contraction strength). Dopamine and epinephrine are also B-agonists.
Two other categories of positive inotropes are cardiac glycosides (digoxin, digitoxin) and
phosphodiesterase (PDE) inhibitors like milrinone and amrinone.
A 2-week old calf is presented that is dehydrated and almost emaciated from weight loss. She has a 1 week history of watery, foamy diarrhea and exhibits tenesmus during examination.
The calf is the only sick one in a mixed group of calves that range from 3 weeks to 2 months of age
What is the diagnosis?
A - Colibacillosis
B - Cryptosporidiosis
C - Coccidiosis
D - Ostertagiasis
E - Coronavirus
B Cryptosporidiosis
Watery diarrhea in a SINGLE animal (1-4 weeks) in a group, plus emaciation suggests Cryptosporidiosis.
Expect a more acute, lethal presentation of hemorrhagic diarrhea in 1-4 DAY old calves with Colibacillosis, and multiple cases with the viral diarrheas like Rotavirus - (5d-2 wks old, self limiting); Coronavirus, (4-30d).
OLDER-animal diarrheas on this list include Coccidiosis ( Older than 21 days and in ALL ages, bloody diarrhea, tenesmus) Ostertagiasis (anorexia, poor growth, diarrhea in less than 2 year olds on pasture- a chronic disease).
Which one of the following choices is the most appropriate treatment for the male guinea pig seen in this image?
A - Fipronil SQ
B - Griseofulvin PO
C - Ivermectin SQ
D - Penicillin G IM
E - Amitraz dips, once weekly
B Griseofulvin PO
The preferred answer is griseofulvin. This is ringworm in guinea pigs, which is usually self-limiting with good husbandry and sanitation.
Treat isloated lesions with topical miconazole, griseofulvin or butefanine.
Systemic treatments include fluconzole or griseofulvin. Remember that griseofulvin is teratogenic and must not be given to pregnant females.
Avoid fipronil and penicillins in guinea pigs. Amitraz is used against demodectic mange, not ringworm.
A 6-year old quarterhorse gelding is presented in September in North America with a three-day history of depression, poor appetite, fever and worsening gait. The owner says the horse seems weak on his hind legs, stumbles and sometimes presses his head against the wall of his stall.
The horse is ataxic and hypermetric in all four legs. Serum antibody titers to EEE, WEE, and VEE are low. A Western Blot test of CSF for antibodies toSarcocystis neurona is negative.
Which one of the following diagnostic tests should be performed next?
A - Serum IgM capture ELISA for West Nile Virus
B - MRI to rule out nigropallidal encephalomalacia
C - CSF tap and test for Japanese encephalitis
D - Plasma antibody test for St. Louis encephalitis
E - Serum AGID for equine infectious anemia
A Serum IgM capture ELISA for west nile virus
Serum IgM capture ELISA for West Nile Virus. Think of the equine encephalidities in a febrile horse, especially in the fall months. Because serum antibody tests for EEE, WEE and VEE are low, West Nile virus encephalitis is the big remaining rule out.
Look for variable and nonspecific signs like depression, low-grade fever and anorexia in combination with neurologic signs like head-pressing (image), ataxia (often hind-end weakness or paralysis) and visual impairment. IgM capture ELISA is the test of choice.
Remember that in most states and provinces, you must REPORT a horse with clinical signs of encephalomyelitis, even if the test results are not in yet.
With equine infectious anemia (EIA), think of recurrent fever, weight loss, dependent edema, petechial hemorrhages (image) and icterus.
Think of ataxia and atrophy with equine protozoal myeloencephalitis (EPM) due to Sarcocystis neurona.
A 1-week old male quarterhorse foal is presented who was born weak. The foal required a neonatal intensive care unit and a lot of handling in his first few days of life.
He has 4-day history of wet dribbling, swollen umbilical area and a scalded ventrum.
What is the diagnosis?
A - Hypospadias
B - Omphalophlebitis
C - Umbilical hernia
D - Uroperitoneum
E - Patent urachus
E Patent urachus
his is a classic history for acquired patent urachus. The dripping tissue tag in front is the umbilicus; penis is caudal. Follow this link to see an image of equine umbilical anatomy.
Recall that the urachus connects fetal bladder to allantoic sac by way of the umbilicus during gestation. Normally, urachus closes in the first days after birth.
A COMMON problem. Can be congenital, but MOSTLY associated with EXCESSIVE HANDLING, (ie: improper lifting, handling umbilicus too much). In fact, patent urachus develops in high % of foals in neonatal intensive care. Also associated with umbilical infection. One review of 16 foals with umbilical infections found 13 (81%) also had patent urachus.
With Uroperitoneum, look for stranguria, enlarging abdomen.
Umbilical hernias may become hot and infected, and possibly leak a little pus, but are not characterized by clear fluids leaking out for days.
Expect urine leaking from the penile anatomy, not the umbilicus with Hypospadias.
A cow is presented with pruritus and crusts around the face, as shown in image 1. Image 2 shows the result of a skin scrape.
What is the diagnosis?
A - Psoroptic mange
B - Trombiculidiasis
C - Cutaneous onchocerciasis
D - Chorioptic mange
E - Sarcoptic mange
E Sarcoptic mange
This is Sarcoptic mange. Sarcoptes NOT common in cattle (think pigs, dogs).
Look for crusty pruritus starting on the head and neck. Follow this link to see a Merck image of canine sarcoptic mange.
On skin scrape, look for short legs and long UNsegmented pedicles on sarcoptes. In CONTRAST to the long legs and short UNsegmented pedicles of chorioptes (Merck images, both).
Which one of the following diseases causes hock sitting, ataxia, and paralysis in chicks 1-2 weeks of age and blue opacity of the lens in those that survive the acute phase of the disease? The disease can affect chickens, pheasants, quail, and turkeys.
A - Avian encephalomyelitis
B - Infectious laryngotracheitis
C - Mycoplasma gallisepticum
D - Fowl cholera
E - Avian metapneumonia
A Avian encephalomyelitis
Avian Encephalomyelitis, also called epidemic tremor, is the most likely diagnosis. This disease has about 60% morbidity and 25% mortality.
Other differentials would include vitamin E deficiency, thiamine deficiency, Newcastle disease, and Marek’s disease, however, these do not typically cause cataracts.
M gallisepticum typically causes a chronic respiratory disease in chickens and infectious sinusitis in turkeys.
Which choice describes inflammation of an acquired bursa over the dorsal carpus in the horse?
A - Hygroma
B - Ulceroproliferative stomatitis
C - Atheroma
D - Villonodular synovitis
E - Suspensory desmitis
A. Hygroma
A hygroma is inflammation of an acquired bursa that develops where normally there is no bursa due to trauma to the dorsum of the carpus. In dogs, you frequently see hygromas at bony, unpadded areas like the elbow.
Villonodular synovitis is an inflammation of the synovial membrane of the dorsoproximal aspect of the forelimbfetlock joints.
Ulceroproliferative stomatitis is a progressively worsening gingivitis and stomatitis in cats. The glossopalatine arches often have severely ulcerated, friable, inflamed, and proliferative lesions. Click here to see a cat with ulceroproliferative stomatitis.
A sebaceous cyst in the dorsolateral aspect of the nasal diverticulum (false nostril) is an atheroma. In humans, an atheroma usually refers to a fatty deposit in the intima (inner lining) of an artery, resulting from atherosclerosis.
An 11 year old neutered male Doberman pinscher presents with a 2 week history of limping on the left fore.
The medial digit is swollen and the nail is deviated laterally. Ulceration and proliferation are present in the ventral nail bed.
Cytology of the mass is inconclusive. Chest radiographs are clear. Following amputation of the digit, histopathology indicates that the mass is a malignant melanoma.
Which of the following is the most correct long term prognosis for this case?
A - Poor
B - Excellent
C - Good
D - Fair
E - Cannot say
A Poor
The long term prognosis is poor. Median survival with resection is 12 months, with a 30% local recurrence rate.Melanoma of the digit is an aggressive, infiltrative tumor, with substantial metastatic potential and a poorer prognosis than cutaneous melanoma or other types of neoplasia.
Some reports indicate that melanomas are not very responsive to radiotherapy, especially if used alone. However, it is utilized for palliative therapy and is recommended following resection, especially when complete excision is not possible.
The efficacy of chemotherapy for subungual melanomas is unclear, but some patients have responded well. Therapy with a DNA vaccine has shown promise in some cases.
Good info here: Brockley LK, MA Cooper MA, & Bennett PF. 2013. Malignant melanoma in 63 dogs (2001–2011): the effect of carboplatin chemotherapy on survival. New Zealand Vet Journal, 61(1): 25-31.
Remember - malignant melanoma may present as swelling of the digit, often with loss of the nail and destruction of bone, much like osteomyelitis. Radiographs and a biopsy are indicated for older dogs that present with a festering, swollen toe.
Click hereto see a radiograph of osteomyelitis in a dog’s toe.
In contrast, the prognosis is good for dogs with digital squamous cell carcinoma (SCC). 95% of dogs with digital SCC survive 1 year after amputation and 75% survive 2 years after amputation.
SCCs have a low metastatic rate; most have not metastasized at the time of diagnosis. Chest radiographs and aspiration of local lymph node(s) for cytology are necessary to accurately assess prognosis.
Ref: Cote, Clinical Vet Advisor-Dogs and Cats, 2nd ed. pp. 711-13, 1046-8, Blackwell’s 5-Min. Vet Consult Canine-Feline, 4thed. pp. 878-9, 1290, and the Merck Veterinary Manual online edition.
A 5-year old Arabian mare is presented. The owner is not happy. This same horse was treated for strangles 2 weeks ago, and now the mare is sick again.
The horse has a 48-hour history of urticarial wheals on its skin that progressed to sharply demarcated edema of the muzzle, eyes, belly and limbs. She reacts as if it is painful when the edema is checked .
The horse breathes heavily, with stridor, dyspnea and diarrhea.
There is petechiation and ecchymoses on the mucous membranes and the muzzle is a reddish, mulberry color.
T=102.2 F (39 C)..[N=99-101.3 F]
HR=32 bpm……….[N=28-40]
RR=12 brpm………[N=10-14]
What is the clinical diagnosis?
A - Potomac Horse Fever
B - Equine salmonellosis
C - Lyme disease
D - Purpura hemorrhagica
E - Equine viral arteritis (EVA)
You chose D, the correct answer!
Purpura hemorrhagica. History of strangles, Streptococcus equi equi followed 2 weeks later by a mixed clinical picture(ie: afebrile, purpura, painful edema, respiratory difficulty, diarrhea or colic) is a classic presentation for Purpura hemorrhagica. Most common cause is sensitization to Strep equi from strangles or Strep equi bacterin vaccine. Less commonly see after Equine influenza, or chronic suppurating wounds. Due to immune complexes damaging vasculature.
For edema in horses, remember “Big 3 are PEE” Purpura, EIA, EVA.
Potomac Horse Fever (Neorickettsia risticii) presents as a febrile colitis/diarrhea, with laminitis 3-5 d after diarrhea: A big rule out is Salmonella (think septicemia/fever + diarrhea). PHF occurs in northeastern U.S. river valleys in JULY and AUGUST.
Lyme disease presents as lameness. ie: arthritic joint(s), low grade fever, reluctant to move. More a dog, human disease.
With Equine viral arteritis (EVA) see conjunctivitis, rhinitis. If very sick, see severe depression, cough, ventral edema, limb edema.
Refs: Colahan and Mayhew, Eq Med and Surg 5th ed. pp. 1457-8, Pasquini’s Guide to Equine Clinics, 3rd ed. pp. 42-3, 136-144, and the Merck Veterinary Manual online edition.
A client is considering the purchase of a 12-year old prize-winning thoroughbred mare for breeding. The pathology report from an endometrial biopsy says the mare is category III by the Kenney scoring system.
What advice is most appropriate to give the client?
A - Don’t buy this mare for breeding
B - 10%-50% chance of bringing a foal to term
C - 80%-90% chance of bringing a foal to term
D - 50%-80 chance of bringing a foal to term
E - Best to breed by artificial insemination
You chose A, the correct answer!
Don’t purchase a category III mare for breeding. Endometrial biopsy predicts a mare’s ability to carry a foal to term and category III is the worst news. (Remember “3 strikes and you are out”).
Endometrial biopsies are classified into 3 types by the Kenney system according to degree of periglandular uterine fibrosis and scarring. The Kenney system gives a % probability that a mare can carry a foal to term. Category I is best. Most horses fall in category II. Category III is worst.
Category I No changes
(80%-90%)
Category IIA Minor changes
(50%-80%)
Category IIB Moderate changes
(10%-50%)
Category III Severe changes.
Less than 10% probability can carry a foal to term.
A middle-aged, depressed, coughing, exercise-intolerant Doberman pinscher is presented. The dog has a rapid and irregular heart rate.
What disease is at the top of the differential diagnosis list?
A - Dilated cardiomyopathy
B - Mitral regurgitation
C - Left-sided congestive heart failure
D - Wolf Parkinson White syndrome
E - Tricuspid insufficiency
You chose A, the correct answer!
This is a classic presentation for dilated cardiomyopathy. Prognosis is GUARDED- with Rx may live 6 mos-2 years. Px especially poor for Dobies.
Rx varies, but foundation includes the “3 D’s” – Diet (Low salt), vasoDilators (Enalapril), Diuretics (Furosemide), +/- Digoxin (+ inotrope to strengthen contraction). NOTE that Dobies can be sensitive to digitalis, so may need lower doses.
So, remember your “DCM D’s” : “Depressed Dilated Dobies need Diet, Dilators, Diuretics (and maybe Digoxin, but overDose is Doom).”
Which diuretic is a competitive antagonist for aldosterone sometimes used in treatment of congestive heart failure?
A - Thiazides (chlorothiazide, hydrochlorothiazide)
B - Furosemide
C - Osmotic diuretics (Mannitol, DMSO)
D - Carbonic anhydrase inhibitors (Acetazolamide)
E - Potassium-sparing diuretics (Spironolactone, Amiloride)
You chose E, the correct answer!
Potassium-sparing diuretics (spironolactone, amiloride) are aldosterone antagonists sometimes used with furosemide as part of the treatment plan for congestive heart failure (CHF).
Aldosterone, the mineralocorticoid produced in the adrenal cortex, acts on the distal convoluted tubules (and collecting ducts) of the nephron to retain Na+ and water, secrete K+ and increase blood pressure. Clinically, look forincreased aldosterone secretion (increased blood pressure) with CHF.
In contrast, see decreased aldosterone secretion (and decreased blood pressure) with hypoadrenocorticism.
