Canine Top Twenty Diseases - Part 3 Flashcards
what is the classic case presentation of ethylene glycol toxicity at 1-2 hours post-ingestion? what about 24-72 hours?
1-2 hours: stupor, stumbling, ataxia, nausea, PU/PD
24-72 hours: clinical signs related to renal failure such as anorexia, lethargy, PU/PD, & vomiting
when can an ethylene glycol test be used to diagnose an animal with toxicity?
detects it 30 minutes to 12 hours after ingestion
what crystals shown in the photo are seen with ethylene glycol toxicity?
left crystal ‘dumbbell’ - calcium oxalate monohydrate
right smaller crystal that looks like an envelope - calcium oxalate dehydrate crystal
what lab abnormalities are seen on urinalysis & biochemistry panels of dogs with ethylene glycol toxicity?
urinalysis - isosthenuria as renal failure develops & calcium oxalate crystals seen 3-18 hours after ingestion
chemistry panel - high anion gap metabolic acidosis, azotemia, hyperphosphatemia, hypocalcemia, & hyperglycemia
when is the best window for treatment in ethylene glycol toxicity cases?
less than 8-12 hours post ingestion
what treatment is used for ethylene glycol toxicity?
decontamination - emesis, activated charcoal (need a lot because ethylene glycol has a low affinity for it)
fomepizole - prevents conversion to toxic metabolites
7% ethanol solution parenterally
supportive care - fluids, or hemodialysis/peritoneal dialysis if oliguria/anuria are present
what is the prognosis of ethylene glycol toxicity?
fair to good if aggressive intervention occurs within 8-12 hours of ingestion - otherwise poor
what are some reasons a dog may have a false positive ethylene glycol test?
propylene glycol or glycerol in activated charcoal, semi-moist dog foods, or injectable diazepam
what is the possible breed disposition of parvo?
dobermans, rottweilers, pit bulls, german shepherds, & dachshunds
what is the classic case presentation of parvo?
puppies less than 8 months old & unvaccinated adults - vomiting, hemorrhagic diarrhea, lethargy, & inappetence
what is the etiology of parvo?
non-enveloped single-stranded DNA virus
what is seen on a CBC & chemistry in dogs with parvo?
CBC - leukopenia/neutropenia
chemistry - hypoalbuminemia, hypoglycemia, hypokalemia, pre-renal azotemia
how is parvo diagnosed?
fecal ELISA test - screen for concurrent worms
suspected lab findings - leukopenia/hypoalbuminemia/hypoglycemia
what treatment is used for parvo?
fluid therapy, IV - + KCL/dextrose if needed or colloids
broad spectrum bactericidal antibiotics -ampicillin, cephalosporin, unasyn)
empirical deworming
nutritional support - trickle feeding if vomiting is controlled or parenteral if enteral trickle enteral isn’t tolerated
when may false positives/negatives be seen on parvo ELISA tests?
false positives - 5-15 days after vaccination
false negatives - if tested too early in the disease course
what is the pathogenesis of parvovirus? what are the most common strains? why does disinfection have to be so intense?
virus attacks the small intestinal crypt cells, lymphopoietic tissue, & bone marrow leading to chronic small intestinal villous blunting
CPV-2b most common in USA & CPV-2c is becoming more common
virus is very resistant - clean & then use bleach solution to kill the virus
what is the classic case presentation of gastric torsion/volvulus?
older, giant or large breed dog with a narrow/deep chest cavity
abdominal distension (can ping like a cow with a displaced abomasum), unproductive retching, ptyalism, discomfort, restlessness, & collapse
what radiographic view is taken to diagnose GDV? what is seen on radiographs to diagnose gastric torsion/volvulus?
right lateral of the abdomen
gas distended pylorus cranial to the fundus - double bubble or smurf hat
use a DV if necessary - not a VD
why use a DV over a VD in a dog with possible GDV?
a VD can cause aspiration
what lab findings may be seen in dogs with a GDV?
hemoconcentration, increased lactate, & +/- DIC
what treatment is critical to start for a GDV dog prior to radiographs?
large bore IV catheters & fluids
what treatment is used for GDV?
iv fluids
decompression of the stomach - trocharization or pass an NG tube
pain meds - opioids
surgery - further decompression & de-rotation, gastropexy, +/- gastric resection/splenectomy
post op - fluids, analgesia, abx, gastric acid reducers, monitor for arrhythmias (ventricular most common), & pro-gi motility meds
what factors are associated with a poorer prognosis in GDV cases?
gastric necrosis
pre-op lactate level greater than 6 mmol/L
greater than 5 hour lag time from onset to evaluation
what is the classic case presentation of hypothyroidism?
mid to large sized middle aged dog - weight gain, lethargy, lameness, alopecia (rat tail/thin hair/truncal symmetrical), cold intolerance, uncommon neurologic signs, & myxedema coma (rare)
what is seen on a CBC/chem of a hypothyroid dog?
CBC - mild non-regenerative anemia
chemistry - hyperlipidemia (both cholesterol & triglycerides)
how is hypothyroidism diagnosed?
total T4 - typically low but may be low-normal if autoantibodies are present
free T4 by equilibrium dialysis measures metabolically available T4 (low confirms hypothyroid & rules out euthyroid sick)
TSH - normal to increased
serum thyroglobulin autoantibodies increased in lymphocytic thyroiditis
what test would you run to rule out euthyroid sick syndrome from hypothyroidism?
free T4 - measures the metabolically available T4, so if it is low, confirms hypothyroidism & rules out euthyroid sick syndrome
what treatment is used for hypothyroidism?
oral T4 - levothyroxine sodium
IV T4 for myxedema coma
what is euthyroid sick syndrome?
when other disease processes cause lower T4 levels
what is the classic case presentation of cataracts?
cloudy white pupil & decreased vision
what is the classic case presentation of cherry eye?
young (less than 2 years) - english bulldog, beagle, shih tzu, cocker spaniels predisposed
smooth, moist, reddish-pink mass at the medial canthus
what is the classic case presentation of uveitis?
conjunctival hyperemia, photophobia, blepharospasm, aqueous flare, iris color change, & midrange to miotic pupils
what is the classic case presentation of glaucoma?
big blue eye (buphthalmos)
visual impairment & tortuous episcleral vessels
how are cataracts diagnosed?
ophthalmic exam
blood & urine glucose (rule out diabetes mellitus)
ocular ultrasound & electroretinography
how is uveitis diagnosed?
tonometry to measure intra-ocular pressures
less than 10 mmHg - consistent with uveitis
greater than 30 mmHg - consistent with uveitis secondary to glaucoma or just secondary to uveitis
systemic work up for underlying cause - CBC, chem, imaging
how is glaucoma diagnosed?
tonometry - IOP over 30 mmHg
gonioscopy - visualization of the iridocorneal angle
ocular ultrasound - evaluate deeper ocular structures
how are cataracts treated?
cataract surgery by experienced/boarded vet ophthalmologist
how is cherry eye treated?
surgical replacement of the gland of the 3rd eyelid
how is uveitis treated?
topical & systemic steroids or NSAIDS - unless secondary to protozoal/fungal infection or corneal ulceration
topical atropine to decrease pain of iridocyclospasm
treat underlying cause
how is acute glaucoma treated?
decrease IOP & pain - topical or systemic carbonic anhydrase inhibitors, topical beta-adrenergic antagonist or blocker, mannitol, +/- topical or systemic steroids
how is chronic glaucoma treated?
topical prostaglandins or surgery to enucleate the eye
what endocrine disease can cataracts be associated with?
diabetes mellitus
what is the prognosis of cataracts with surgical intervention?
good to excellent
what is the prognosis of cherry eye? when should the 3rd eyelid be removed?
good to excellent with surgery
removal of the 3rd eyelid should only be done if cancerous because of high risk of lifelong KCS if removed
T/F: more than 50% of cases of uveitis are idiopathic
true
why treat the contralateral eye or a blind eye with glaucoma?
need to treat the contralateral eye prophylactically with IOP reducing meds
even if the eye is blind, you still need to treat the eye to address pain!!!