Top 20 Canine

Question 1

Canine

Diabetes mellitus

CS? Dx? Supportive? Tx/Management? Meds to avoid?

Answer 1

Classic CS
* PU/PD/PP + weight loss

Diagnosis
* persistent hyperglycemia (>300 mg/dL)
* glucosuria +/- ketonuria
* fructosamine - estimates BG over last 2 weeks, can help r/o stress hyperglycemia

Supportive
* Often have elevated liver enzymes and cholesterol too

Treatment
* BID insulin - intermediate or long-actin insulin (vetsulin, NPH, etc.) if stable - monitor with BG curve at first if you can
* Dietary management - high fiber, low calorie
* +/- Oral hypoglycemics - may decrease insulin requirements & resistance – Glipizide (glucotrol) - efficacy controversial although the MC used

Avoid corticosteroids - can contribute to insulin resistance
– Even though diabetes can have an immune component - don’t give immunosuppressants

Question 2

canine

why use high fiber, low calorie diet in diabetics? Diet to avoid?

Answer 2

High fiber: delays glucose absorption in GI, can increase sensitivity to insulin

Low calorie/exercise: increase insulin sensitivity

Avoid high fat - pancreatitis can be underlying cause of diabetes

Question 3

Diabetic ketoacidosis

CS? Dx? Tx?

Answer 3

CS
* Anorexia, vomiting, weakness

Dx
* Severe metabolic acidosis, BG >500 mg/dL, ketonuria

Tx
* Short-acting insulin (regular) q6-8 or CRI until ketosis resolves
Frequent BG monitoring - want it to decline gradually
* Aggressive IV fluids with K and P supplementation as needed
* Correct acidosis (bicarb if low and fluids not working for acidosis)

Question 4

Canine

HypERadrenocorticism

CS? Types? Dx? Rule out/screening? Supportive? Tx?

aka Cushings, HypERcortisolism

Answer 4

CS
* PU/PD/PP/Panting
* Pendulous abdomen, truncal alopecia
* Pyoderma
* Thin skin
* Hyper pigmentation
* Seborrhea
* Calcinosis cutis

Types
* MC Pituitary-dependant (PDH) - tumor in pituitary secretes ACTH
* Adrenal tumors (AT) that secrete cortisol
* Iatrogenic steroids w/o adequate weaning period

Dx
* LDDST - highest sensitivity, MC used
* ACTH stim - best for iatrogenic an used for monitoring therapeutic response (prevent iatrogenic Addisons)
* HDDST - rarely used, can DDx between PDH and ADH in hard cases

Screening/Supportive/Rule-outs
* normal ALP = unlikely to have Cushings
* supportive = elevated ALP, hypERcholesterolemia, stress leukogram, USG hyposthenuric (<1.010) +/- proteinuria
* rule OUT = normal urine cortsiol:creatinine

Tx
* PDH - trilostane, mitotane, Sx (risky), or radiation
* ADH - trilostane, mitotane, Sx (risky)
* Iatrogenic - slow taper with ACTH stim monitoring

Question 5

what is trilostane? mitotane?

Answer 5

Trilostane - inhibits enzymes needed for cortisol production
Mitotane (Lysodren) - adrenocortical lysis

Question 6

LDDST test for Cushings

Answer 6

Measure baseline cortisol
Give IV dexamethasone (0.01 mg/kg)

8 hour cortisol level >1.4 ug/dL = likely Cushings

4 hour cortisol level <50% baseline or <1.4 = likely PDH

Question 7

Canine

Collapsing trachea

predisposed? types? causes? CS? Tx?

Answer 7

Predisposed
* older small breed dogs, especially obese

Types
* Intrathoracic - collapse on expiration
* Extrathoracic (neck) - collapse on inspiration

Can be primary or secondary due to cardiopulmonary disorders

Clinical signs
* Expiratory distress, honking cough on palpation/excitement +/- a retch at the end of cough
* exercise intolerance, cyanosis if severe

Diagnosis
* eliciting a coughing spasm on tracheal palpation
* rads (hard for dynamic collapse sometimes) - ENd expiratory for INtrathoracic collapse
* Fluoroscopy
* endoscopy

Treatment
* May need sedation to break cough cycle in acute episodes
* Medical - 70% respond = Weight loss, Anxiolytics, Bronchodilators (theophylline, terbutaline), Cough suppressants (hydrocodone), Short course corticosteroids
* Surgical - if medical doesn’t work enough, not all that successful = Dorsal tracheal membrane plication, Intratracheal stent, External tracheal support

Question 8

canine

IMHA

predisposed? path? CS? Dx? Tx?

Answer 8

Cocker spaniels predisposed

CS
* Lethargy
* pallor
* fever
* icterus, bilirubin/hemoglobinuria

Dx
* saline slide agglutination test (blood clumps)
* Coombs test - looks for antibodies against RBCs
* Blood smear - spherocytosis
* CBC - normocytic normochromic regenerative anemia
* Rads - screen for neoplasia

Tx
* immunosuppression (corticosteroids or immunomodulators like cyclosporine or azathioprine), blood products as needed
* Prevent thromboembolism - aspirin, LMW heparin, clopidogrel

Question 9

canine

IVDD

CS? MC location? Types? Dx? Tx? Prognosis?

Answer 9

MC location
* Usually T3-L3 = UMN hindlimbs

CS
* Pain in neck/back (arched back or head down
* paraparesis
* paraplegia
* ataxia

• Hansen’s Type I Disc herniation chondrodystrophic breeds such as Dachshunds, corgis, Shi-tzu
• Acute, painful, emergency
• Nucleus pulposus extrudes through the annulus

Hansen’s Type 2 disc herniation
* non-chondrodystrophic breeds
* usually Chronic, nonpainful, nonemergency
* Annulus hypertrophies or bulges

Dx
* CT(safest, best quality)
* MRI (fastest)
* Myelogram (invasive, chance of seizures during recovery)

Tx
* Conservative = NSAIDs, strict cage rest 8 weeks (50% will improve) - only use if NO neurologic signs (ie, pain only)
* Surgical = decompression via hemilaminectomy (thoracic) or ventral slot (cervical) - used in nonresponsive to medical or has true neuro signs or if the owner wants

Prognosis
* Ambulatory = excellent
* Nonambulatory = guarded w/o Sx, excellent w/ Sx
* Nonambulatory + deep pain negative = 50% chance of regaining function only ig Sx done within 24h

Question 10

canine

heart failure

CS? Dx? Acute tx? Chronic tx?

Answer 10

CS
* Exercise intolerance
* Cough
* Abdominal distension
* +/- heart murmur, arrhythmia
* Harsh lung sounds/crackles
* If LHF → pulmonary edema
* If RHF → ascites, pleural effusion

Dx
* Rads = cardiomegaly (>3.5 intercostal spaces, dorsal tracheal deviation) enlarged pulmonary veins, alveolar-interstitial lung pattern in caudodorsal lung field
* Echo = LA +/- LV enlargement, +/- poor contractility, valvular insufficiency, RA/RV dilation

Acute tx
* Oxygen
* furosemide (loop diuretic)
* nitrates - (nitroprusside, nitroglycerin for venodilation (both do this) + arteriodilation (prusside only)
* Mild sedation if needed

Chronic management
* Na-restricted diets - Decreases preload
* ACE inhibitors (enalapril) - Decreases preload, reduces afterload by prevention AT2 (a vasoconstrictor)
* Diuretics (furosemide) - Decreases preload
* Pimobendan - Positive inotrope, improves systolic function

Question 11

canine

Heartworm disease

Life cycle, CS, pathology, Dx, Tx, Prognosis, Prevention, DDx

Answer 11

**Dirofilaria immitis life cycle and pathology
**
* Depend on mosquitoes for life cycle
* Transmitted as L3 larvae through mosquito bites → take 6 months for microfilariae to release into blood and thus diagnosis
* Might carry Wolbachia bacT which is intracellular and used for HW survival
* Adults live in pulmonary artery and RV - can stay for 3-5y
* RVH → pulmonary hypertension

Clinical signs
* Exercise intolerance
* cough
* abdominal distension
* weight loss
* poor body condition

Diagnosis
Antigen SNAP test
* detects female adult worms starting @5 months post-infection
* False negatives possible (complex formation, no females, light load)

Microfilaria tests - always do this due to potential for false negatives on snap
* ID on smear
* Modified Knotts
* Filter test

TXR
* RV hypertrophy (reverse D)
* prominent/dilated pulmonary Aa
* +/- pulmonary parenchymal dz

Echo
* pulmonary A dilation
* RH dilation
* visible worms in pulmonary A
* caval syndrome - HW in RA/RV

Supportive
* Proteinuria
* Eosinophilia

Treatment
Macrocyclic lactones (preventatives = ivermectin, milbemycin)
* give for 2 months (2 doses) prior to adulticide
* Pre-tx with diphenhydramine and corticosteroids if microfilaria positive
* Prevents new infections + eliminates susceptible larvae and microfilaria

Doxycycline
* give for 30d prior adulticide
* Treats Wolbachia → makes worms more susceptible to adulticide

Corticosteroids
* for 1-2 months prior to adulticide if symptomatic or are microfiliaria positive to control CS of pulmonary thromboembolism
* tapering anti-inflammatory dose

Immiticide/adulticide = Melarsomine (IM)
* kills 98% adult worms
* 1st injection → wait 4-6 weeks → 2nd injection → wait 24 hours → 3rd injection
* Risk of thromboembolic dz = strict rest during this tx and 6-8 weeks after

Sx for caval syndrome

Prognosis
* Good-guarded
* Poor-grave if caval syndrome

Prevention
* monthly low dose PO ivermectin or milbemycin, topical selamectin or moxidectin/imidacloprid

DDx
* Acanthocheilonema reconditum - not pathogenic - looks similar on smear

Question 12

canine

pyometra

MC etiology/Pathology? CS? Dx? Tx? Prognosis?

Answer 12

Etiology & Pathology
* MC etiology = E. coli
* MC occurs from hormonal imbalance during diestrus 3-4 weeks post-estrus - P4 dominance promotes endometrial growth, myometrial activity, and inhibits leukocyte infection response
* In dogs >8y, Cystic endometrial hyperplasia MC cause, which is due to repeat exposure to P4 in intact females → thickening of the endometrium and hypertrophy of glands

Clinical signs
* Mucopurulent or hemorrhagic vaginal discharge
* enlarged teats
* PU/PD
* V/d
* Abdominal pain
* Large, palpable uterus

Diagnosis
* AXR - fluid-filled loops in caudal abdomen
* Vaginal cytology - degenerate neutrophils +/- phagocytized bacteria
* AUS - enlarged fluid-filled uterus

Treatment
* Stabilize - IVF, abx, analgesics
* SURGERY (OHE)
* If owner refuses → prostaglandins to increase myometrial contractions, breed next cycle - recommend referral

Prognosis
* good to guarded

Question 12

canine

flea allergy dermatitis

MC age/season? CS? Dx? Tx?

Answer 12

MC in warm seasons and >6mo old

CS
* acute onset pruritis
* caudodorsal alopecia

Dx
* Finding fleas or flea dirt
* Up to 15% do not have evidence of fleas → 3 month flea tx trial

Tx
* Acute - tapering corticosteroids + flea adulticide
* Chronic - monthly adulticide, oral month development inhibitors (lufenuron), environmental control

Question 13

canine

Hip dysplasia

Pathology? CS? Dx? Tx? Prevention?

Answer 13

Path
* instability of 1 or more hip joints
* Hip joint instability often → DJD/OA, coxofemoral luxation (MC in craniodorsal direction)

Clinical signs
* Bunny-hopping gait, difficulty rising
* Juvenile - positive ortolani sign (indicates joint laxity = feel a clunk when manipulating the femur = coxofemoral subluxation)

Diagnosis
* Rads = shallow acetabulum, flattened femoral head, <50% femoral head coverage by acetabular rim, thickened femoral neck
* special rads include OFA (must be 2yo, more subjective) and Penn Hip (based on distraction index, more accurate at younger age, ideally done at 1yo). DI <0.3 is best

Treatment
* Medical/conservative: NSAIDs, weight management, neutraceuticals, light low-impact exercise - up to 80% improvement
* Juveline Pelvic symphysiodesis - encourages acetabular coverage/growth. Can only be done 14-20w old
* Triple pelvic osteotomy - gives more acetbular coverage, only done in <1yo with minimal changes/laxity and with already good acetabulums
* Femoral head and neck ostectomy - best used when <30lbs, well muscled, and good BW. Often results in mechanical (but non-painful) lameness

Prevention
* good BW
* breed based on PennHIP/OFA

Question 14

canine

Osteochondritis dissecans

predisposed? path? CS? Dx? Tx? Prevention?

Answer 14

Pathology
* Abnormal cartilage development → separation from underlying bone

Clinical signs
* Acute lameness, joint effusion, decreased ROM

Diagnosis
* Rads or CT- effusion, widened joint space on one side, flattening of subchondral bone, joint mice

Treatment
* Medical - NSAIDs, nutraceuticals
* Surgical debridement

Prevention
* good dog food for breed, avoid excess Ca and vitamin D

MC young large breeds

Question 15

canine

panosteitis

predisposed? CS? Dx? Tx? Prognosis?

Answer 15

MC in GSDs 5-18mo

CS
* Pain in long bones, lameness for weeks-months at a time

Dx
* Rads = patchy increased opacity (trabecular pattern) and periosteal new bone

Tx
* Pain control, rest

Prognosis
* Likely to recur many times until 2yo but, prognosis excellent and likely to self-resolve after that

Question 16

canine

Hypertrophic osteodystrophy (HOD)

Predisposed? CS? Dx? Tx? Prognosis? Causes?

Answer 16

Weimaraners predisposed, often littermates, but large rapidly growing dogs in general are common

CS
* MC affects distal metaphysis of the forelimbs but can be all long bones
* swelling/pain in distal limb, metaphyseal pain + fever +/- recent hx of vaccination

Dx
* Rads = metaphyseal flaring, “double physeal line” in areas of bony proliferation, abnormal radiolucent lines within metaphysis

Tx
* rest, pain medication, time, +/- steroids

Prognosis
* Usually self limiting but often recurs while growing

Exact cause unknown
* Vaccine?
* Ca/P imbalance?
* Vitamin C deficiency?
* Distemper?

Question 17

canine

Legg-Calve-Perthes disease

predisposed? CS? Path? Dx? Tx? Prognosis

Answer 17

= avascular necrosis of the femoral head

Predisposed = Young, small-breed dogs prior to closure of capital femoral physis 3mo-1y

CS = hindlimb lameness

Path = Disruption of bloodflow → collapse or fragmentation of femoral epiphysis

Dx
* Rads = shortened femoral neck, osteochondrosis, muscle atrophy, loss of bone opacity at femoral epiphysis, moth-eaten appearance of femoral head/neck

Tx = FHO (femoral head/neck ostectomy) or total hip replacement, analgesia

Prognosis = good-excellent with Sx

Question 18

canine

ethylene glycol toxicity

Path? CS? Dx? Tx? Prognosis?

antifreeze - tastes sweet to dogs

Answer 18

Pathology and CS
metabolized into alcohol dehydrogenase, glycolic acid, and oxalic acid

Stage 1 = neurologic phase - 30min-12h
* ataxia, acting drunk, stupor? Coma?, anorexia, vomiting, PU/PD

Stage 2 = cardiovascular phase - 12-24h
* Hard to recognize alone
* CS: tachypnea, tachycardia

Stage 3 = 12-72h
* Oliguric renal failure!

Diagnosis
Urinalysis
* Calcium oxalate monohydrate crystalluria as early as 6h
* isosthenuria as renal failure develops

Blood gas
* high AG metabolic acidosis
* elevated osmolar gap (>20)

Chemistry
* HypOcalcemia, HypERphosphatemia
* hypERglycemia
* azotemia

EG test can dected 30min-12h - false positives possible

Treament
In general, tx most effective if done in <8-12h
Decontamination
* emesis, activate charcoal id within 2h

Fomepizole - prevents toxic metabolic conversion (must give early)

4-MP - inhibits alcohol dehydrogenase

20% ethanol - inhibits alcohol dehydrogenase

Symptomatic - GI protectants, IV fluids, diuretics if oliguric

If 8+h → consider hemodialysis, peritoneal dialysis

Prognosis
* good to fair if therapy started within 4-8h
* guarded if azotemic, grave if oliguria/anuria
* If 8-12+h → guarded-grace prognosis - consider dialysis

Question 19

canine

parvovirus

etiology? transmission? path? CS? Dx? Tx?

Answer 19

Etiology
* CPV-2 = nonenveloped, single-stranded DNA virus
Transmission: fecal-oral, fomites

Path
* Destroys cells in intestinal crypts (villous atrophy/blunting), lymphopoietic tissue, bone marrow

CS = fever, lethargy, anorexia, vomiting, diarrhea

Dx
* CBC: leukopenia, neutropenia
* Confirm with fecal ELISA; False positives 5-15d post-vaccine; false negatives if too early
* Chem = hypOalbuminemia, hypOglycemia, hypOkalemia, prerenal azotemia

Tx = Supportive care
* IVF +/- KCl, dextrose, colloids
* Broad spectrum IV antibiotics
* Antiemetics
* Gastroprotectants
* Slow enteral or parenteral feeding as tolerated

predisposed to intussussceptions too

Question 20

canine

GDV

Predisposed? CS? Path? Dx? Tx? Prognosis?

Answer 20

deep-chested large breeds predisposed

Clinical signs
* Non-productive vomiting/retching
* abdominal distension
* Restlessness, nervous pacing
* painful, Increased respiratory rate
* +/- Signs of shock/cardiovascular collapse - tachycardia, weak pulses, pale mucous membranes, prolonged CRT, depression/coma
* Death if do not decompress quickly

Pathology
* Stomach rotates counterclockwise (when viewing cranial-caudal in dorsal recumbency)
* Stomach volvulus → venous compression, congestion, poor perfusion → necrosis
* May also tear short gastric vessels that connect the stomach and spleen
* Air accumulation in stomach → impedes on venous return through vena cava and heart → hypovolemic shock
* May result in global tissue ischemia and SIRS
* Inflammatory mediators and myocardial ischemia may lead to arrhythmias

Diagnosis
* stabilize 1st if you suspect (can be pinged!)
* right lateral abdominal radiograph - smurf hat/popeye arm/double bubble - displaced, gas-filled pylorus
* ECG - arrhythmias common, especially VPCs after surgery
* Blood gas - metabolic lactic acidosis +/- respiratory compensation +/- hypercapnia (gastric distension may impair ventilation)
* Often hemoconcentrated +/- DIC changes

Treatment
Most patients are shocky on presentation and need aggressive resuscitation, supportive care, and monitoring
* Place cephalic catheter(s) - large bore (saphenous has poor caudal venous return)
* Shock dose crystalloid fluids (80-90 mL/kg) - deliver in quarter doses until resuscitated

Decompress the stomach
* Orogastric tube: more effective emptying but requires heavy sedation, tube might be hard to pass, and may cause esophageal trauma/rupture
* Trocarization: more rapid intervention, no sedation required, but limiting decompression is achieved, risk of lacerating gastric wall or puncturing spleen – Do it at the maximum point of tympany – you don’t know if the spleen is on the left or right

Surgical emergency after stabilization
* Need decompression and de-rotation w/ gastropexy + Resect any necrotic tissue – Will see omentum covering the stomach when you enter the abdomen
* +/- splenectomy

Prognosis
* 15-30% mortality
* 75-85% live with Sx and appropriate post-op care

Negative prognosticators
* lactate > 6 mmol/L
* need for resection or splenectomy
* 5+ hours since onset of CS
* recumbent on presentation

Recurrence <4% with pexy, and 50% without

Prevention
* prophylactic gastropexy

Question 21

canine

HypOthyroidism

Sig? CS? Dx? Tx? Prognosis?

Answer 21

MC in older, large breed dogs

CS
* Weight gain
* dermatopathies
* lethargy, bradycardia
* decreased appetite
* possible neuromuscular signs
* cold intolerance
* myxedema

Dx
* Free T4 by equilibrium dialysis - confirmatory and rules out euthyroid sick
* Total T4 low-normal
* TSH - low-normal
* TSH stimulation test, trial therapy

Supportive Dx
* CBC - mild nonregenerative anemia
* Chem - hypERcholesterolemia, hypERtriglyceridemia, lipemia

Tx
* lifelong oral levothyroxine (synthetic T4) w/ periodic monitoring of thyroid levels
* IV T4 for myxedema coma

Prognosis = good with continued management and therapies

Beware false diagnosis - euthyroid sick syndrome

Question 22

canine

cataracts

CS? Dx/Types? Tx?

Answer 22

CS = Cloudy white pupil, decreased vision

Dx/types
* Incomplete = partially opacified, lens defect, can see tapetal reflection through it, animal can still see some through it
* Complete = completely opacified lens defect, cannot see tapetal reflection through it, animal cannot see through it
* Incipient cataract = focal cataract
* Resorbing cataract = lens protein degradation
* Also do a BG and UA (diabetes), ERG

Tx
* Phacoemulsification or other
* Potential to develop secondary uveitis = refer early for best results

Question 23

canine

cherry eye

What is it? Predisposed? CS? Tx?

Answer 23

Prolapse of the 3rd eyelid - congenital

English bulldogs, beagles, Shih tzu, cocker spaniels predisposed

CS/Dx = Smooth, moist pink-red mass at medial canthus

Tx = Morgan pocket or Kaswan anchoring (replace the 3rd eyelid gland)
* If remove gland instead → high risk of KCS = not recommended

Consider not breeding these animals!

Question 24

canine

uveitis

causes? Path? CS? Dx? Tx? Sequelae?

Answer 24

Causes
* bacterial, fungal, viral, rickettsial, immune-mediates, neoplasia, hypertension, trauma
* 50% idiopathic

Path/sequelae
* if Chronic - inflammatory mediators in anterior chamber → destroy cornea and lens proteins → corneal scarring, cataracts, glaucoma if debri plugs iridocorneal angle

CS
* Conjunctival hyperemia
* photophobia
* blepharospasm
* aqueous flare
* iris color change
* +/- miotic pupils

Dx
* Tonometry - IOP <10 mmHg
* Possibly greater if secondary to glaucoma
* Systemic workup for underlying cause

Tx
* Topical steroids or NSAIDs - reduce inflammation - but NOT if secondary to ulcer or infection
* Topical atropine - relieve ciliary spasm, reduce posterior synechiae development
* May worsen secondary glaucoma if they have it
* Tx underlying cause

Question 25

canine

glaucoma

Path? CS? Dx? Tx?

Answer 25

Path
* Primary = inherited, often iridocorneal angle breakdown
* decreased outflow of aqueous humor → increased IOP
* Glaucoma in 1 eye → other likely to develop in 6-12 months (often inherited)

CS
* Buphthalmos, blue eye
* visual impairment
* tortuous episcleral vessels

Dx
* Tonometry - IOP >30
* Gonioscopy - visualize iridocorneal angle
* Ocular U/S

Tx
Goal = increase outflow, decrease aqueous production

Carbonic anhydrase inhibitors - decrease aqueous production
* oral methazolamide
* topical dorzolamide/ acetazolamide)
Prostaglandin analogues
* topical latanoprost

Acute = CAIs, B-antagonists or blockers, steroids

Chronic: prostaglandins, enucleation

Treat both eyes in predisposed breeds

Question 26

canine

pancreatitis

risk factors? predilections? CS? Dx? Tx? Prognosis?

Answer 26

Risk factors
* obesity
* fatty meals
* systemic inflammation, trauma, ischemia
* endocrine dz (cushings, diabetes)
* drugs (azathioprine, l-asparaginase, tetracycline)

Mini schnauzers over-represented

Clinical signs
MC acute GI signs
* v/d, anorexia
* cranial abdominal pain
* “praying position”

If severe, necrotizing
* hypovolemia
* fever
* tachycardia
* jaundice
* SIRS

Diagnosis
cPLI (pancreatic lipase immunoreactivity) SNAP

U/S
* hypOechoic pancreas (edema)
* +/- mottling, enlargement with hypERechoic mesentery (focal peritonitis)

Chem - hyperlipemia (4-5x)

Treatment
* Acute
Fasting, post-duodenal feeding, ultra low-fat diet
Hospitalization, IV fluids
Analgesia
H2 blockers, antiemetics
+/- Abx
+/- plasma, heparin

Chronic
* Low fat, highly digestible diet
* Prognosis depends on presence of complications - acidosis, MOF, DIC, acidosis, peritonitis, etc.

Question 27

canine

Kennel cough

Et? CS? Dx? Tx? Prognosis?

Canine infectious respiratory disease complex (CIRD)

Answer 27

Multiple etiologies
Viruses
* Canine parainfluenza (CPIV)
* canine influenza
* canine adenovirus 2 (CAV-2)
* +/- canine distemper (CDV)

Bacteria
* Bordetella bronchiseptica
* Mycoplasma

Clinical signs
* Exposure to other animals followed by acute onset non-productive cough that may end with a retch

Diagnosis
* B. bronchiseptica - PCR or culture from nasal or oropharyngeal swabs, TTW, or BAL
* TXR - may see pneumonia

Treatment
Cough suppressants - hydrocodone, butorphanol

For bronchopneumonia
* Antibiotics
* Nebulization with saline +/- abx (gentamicin)
* Fluid therapy
* +/- O2 therapy

Vaccination may reduce infection rate and severity
* Modified live CPIV/CAV-2/CDV combo
* Bordetella/CPIV combo

Prognosis - likely to resolve in 7-10 days if no secondary bronchopneumonia

Question 28

canine

megaesophagus

causes? predisposed? CS? Dx? Tx? Prognosis?

Answer 28

Causes
* myasthenia gravis
* vascular ring anomaly
* endocrinopathies - Addisons, hypOthyroidism
* esophagitis
* lead toxicity
* myopathies
* neuropathies
* idiopathic
* Ketamine and xylazine can cause temporary

Congenitally predisposed - may see spontaaneous resolvement!
* GSDs
* mini schnauzers
* fox terriers

Clinical signs
* Regurgitation
* coughing, drooling
* weight loss, weakness
* +/- signs of pneumonia (fever, cough)

Diagnosis
Rads (ventral tracheal deviation), swallow study - air-dilated esophagus, +/- aspiration pneumonia (cranial alveolar)

Dx underlying conditions
* AChR antibody test for myasthenia gravis
* ACTH stim for Addisons
* FT4 for hypothyroid
* Lead level
* EMG/nerve conduction for polymyopathy/ polyneuropathy

Treatment
Diet: high calorie, soft
* fed in upright position and stay there 10-15 minutes after eating
* small, frequent meals are best

Prokinetics to aid gastric emptying and reduce reflux
* cisapride

Acid reducers to decrease acid reflux
* PPIs (pantoprazole, omeprazole)
* H2 blockers (famotidine, ranitidine)

Tx underlying condition

Tx aspiration pneumonia

Prognosis: Most will eventually die of aspiration pneumonia :(

Question 29

canine

osteosarcoma

predeliction? sites? behavior? CS? Dx? Tx? Prognosis?

Answer 29

MC primary bone tumor in dogs
MC in large dogs overall
Bimodal age distribution, <2y and >7y

Location
MC appendicular, but sometimes axial in small dogs
* Mandible, maxilla, scapula, ribs, spine, pelvis
* Mandible better prognosis (70% survive 1y with sx)
* Other locations similar prognosis to appendicular

Appendicular MC
* MC in metaphyseal region of appendicular skeleton
* “Away from the elbow towards the knee” = distal radius, proximal humerus, distal femur, proximal tibia

Behavior
Locally aggressive and highly metastatic
* Metastasis MC to lungs, but also lnn

Clinical signs
Chronic or acute lameness

Diagnosis
Biopsy of bony lesion = gold standard (risk pathologic fx)

Rads
* Lytic (“moth eaten”) lesion in metaphyseal area that does not cross joints, periosteal new bone formation
* If in diaphysis → think its metastatic from another cancer
* TXR - very poor prognosis if metastasis present

FNA - warn about pathologic fracture

Bone Scan or NS - to look for bone metastasis

CT for axial, Sx planning, radiation planning

Chem - elevated ALP = worse prognosis

Treatment
Limb amputation (stage 1st!)
* Considered palliative - 90% of dogs will still develop metastasis

Limb-sparing surgery
* Ostectomy + prosthetic
* High complication rate

Chemotherapy
* can extend MST to 10-12 months
* Cisplatin or carboplatin +/- doxorubicin (adriamycin)

Radiation - palliative only
* Can improve pain for 2-3 months in 75% of cases
* Makes pathologic fractures more likely

Osteoclast inhibitors (bisphosphonates) can improve pain if Sx not an option

Prognosis
* Overall survival 4-12 months
* Amputation alone = 4-6mo
* Sx + chemo = 10-12mo
* If metastasis present = 1-3mo
* Most develop mets despite tx later
* ALP elevation = worse prognosis

Question 30

canine

mast cell tumor

predisposed? Path/CS/Behavior? Dx? Tx? Prognosis?

Answer 30

Predisposed: boxers, pugs, boston terriers, other brachycephalics (Often develop many over their lifetime, but usually are low or intermediate grade with little metastasis)

Pathology/CS/Behavior
Mast cell granules release histamine and heparin (also proteases, cytokines) when they degranulate
* May cause v/d/melena

Can cause GI ulcers, bleeding, poor wound healing, anaphylactoid rxns (hypotension, vasodilation, collapse, etc.)

A great pretender – can look and feel like almost anything
* Cutaneous or subcutaneous mass
* +/- pruritus
* May shrink/swell intermittently

More aggressive at mucocutaneous junctions, prepuce, scrotum, muzzle, digits, pinna

Diagnosis
FNA: single round nucleus (may stain light due to granules taking up so much stain) w/ dark purple cytoplasmic granules
* number of mitotic figures per hpf correlates with how aggressive the tumor behaves

Cannot determine grade via cytology - need biopsy

• Biopsy: if FNA is nondiagnostic and for grading - Patnaik system
• Required to determine grade - technically can only grade cutaneous canine MCTs
• Higher grade = more metastatic

FNA or biopsy of regional draining lnn

AUS and TXR
* If aggressive with high risk of metastasis Eval abdominal lnn, liver, spleen, and thoracic lnn

Buffy coat analysis or bone marrow aspirate – rarely indicated, often have a low yield

Stage the tumor
* Local lnn aspirates
* Abdominal and thoracic imaging
* Bloodwork
* Higher stage = worse prognosis

Treatment
surgical excision with wide margins (2-3cm lateral margins and one fascial plane deep)
* TOC if metastasis not already present

Radiation tx as adjuvant if adequate margins cannot be obtained

Chemotherapy
* vinblastine, lomustine, CCNU, other alkylating agents
* Tyrosine kinase inhibitors = Toceranib (Palladia) - only FDA approved chemo drug for vets

Supportive care
* H1 blockers - diphenhydramine
* H2 blockers - famotidine, cimetidine, ranitidine
* H blockers help reduce histamine release by mast cells (would cause increased gastric acid secretion predisposing to GI ulcers and GI bleeding)
* Glucocorticoids (prednisone) - Cytotoxic to mast cells, stabilizes mast cell membranes, and reduces inflammation associated w/ the tumor

Prognosis
* mostly depends on grade; only MCTs arising from the skin are graded

#1 MC dermal malignancy in dogs

Question 31

canine

lymphoma

CS? Dx? Tx? Prognosis?

Answer 31

Clinical signs
* Generalized lymphadenopathy
* v/d/weight loss
* Dyspnea

Treatment
* Cytology - mostly large lymphocytes/lymphoblasts (much bigger than neutrophils)
* Biopsy for grading and definitive dx
* Staging - txr, aus
* CBC - pancytopenias + lymphocytosis
* Chem - hypERcalcemia
* Bone marrow aspirate
* Flow cytometry or IHC for B vs T cell

Treatment
Prednisone - can decrease response to future chemo

Chemotherapy (CHOP)- doxorubicin, cyclophosphamide, vincristine, L-asparaginase, lomustine
* Many achieve remission

Prognosis for B cell&raquo_space; T cell

Question 32

canine

Predisposed? Et? Tx?

Answer 32

struvite

Usually induced by a UTI/cystitis with urease positive microbes such as Staph or Proteus

Treatment
* abx for UTI using C/S
* +/- cystotomy

Dietary dissolution can work - reduce crystal components
* low Mg, low P, low protein diet (Hills s/d or w/d)

Question 33

canine

Predisposed? Path? Tx?

Answer 33

calcium oxalate dihydrate

Predisposed - Schnauzers, Lhasa apso, yorkies, bichon frise, shih tzu, and mini poodles are predisposed

Pathology
* Most likely to occur in acidic urine
* May occur due to hypERcalcemia (check Ca levels!)

Treatment
* Most difficult and least likely to dissolve
* MC need Sx, voiding hydropulsion, or lithotripsy
* alkalinize the urine w/ diet & low protein to prevent recurrence (Hills u/d or RC Urinary SO)

Question 34

canine

Predisposed? Dx? Tx?

Answer 34

Cystine

Predisposed: Bulldogs, newfoundland, dachshunds, basset hounds, chihuahuas, yorkies predisposed - may have genetic defect

Dx: UA - Cannot be seed on rads

Treatment
Dietary management
* Hills u/d - Reduced protein (methionine),Reduced Na

Alkalinize the diet
* Potassium citrate > sodium bicarbonate
* Thiola (2 -mercaptopropionyl-glycine aka 2-MPG): binds cystine and forms a more soluble compound

Keep on this diet for 1mo → then switch to low purine to prevent recurrence

Question 35

canine

predisposed/causes? Tx?

Answer 35

Urate

Dalmations are predisposed to urate uroliths due to a metabolic defect – they cannot convert uric acid to allantoin

If other breeds make urate stones → think about a portosystemic shunt

Diagnosis - UA only, cannot be seen on radiographs

Treatment
Dietary management
* Reduce protein (low purine), no soy - low purines can cause cardiomyopathy over time?
* Alkalizing diet - potassium citrate or sodium bicarbonate

Allopurinol: decreases uric acid by inhibiting hypoxanthine → xanthine → uric acid
* must reduce protein in the diet or can lead to xanthine stone formation