Top 20 Canine Flashcards

Question

# canine uveitis | causes? Path? CS? Dx? Tx? Sequelae?

Answer 1

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

Answer 2

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

Answer 3

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.

Answer 4

**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

Answer 5

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 :(

Answer 6

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

Answer 7

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

Answer 8

**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 >> T cell

Answer 9

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)

Answer 10

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)

Answer 11

**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

Answer 12

**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