Canine Top Endocrine Diseases Flashcards
what is the classic case presentation of hypothyroidism?
middle aged dog with insidious signs - weight gain, lethargy, exercise intolerance, hypothermia, bilaterally symmetric non-pruritic alopecia with a rat tail & dry coat, rare myxedema with a tragic facial expression
what is the etiology of hypothyroidism?
lymphocytic thyroiditis or thyroid atrophy
what initial screening is done when diagnosing hypothyroidism?
cbc - mild normocytic normochromic non-regenrative anemia chem - possible hypercholesteremia, hypertriglyceridemia serum T4 - low, either true or euthyroid sick syndrome
after initial screening, what diagnostics are done for hypothyroidism?
serum free T4 - if low, true hypothyroidism, if normal, euthyroid sick syndrome TSH - if high, true hypothyroidism, if normal/low, euthyroid sick syndrome
how is hypothyroidism treated? what monitoring is done upon the start of treatment?
oral synthetic T4 (levothyroxine) - gi absorption is poor, given ever 12-24 hours for life, will see slow improvement over weeks to months for monitoring - post-pill T4 4-6 weeks after starting treatment & then every 3-6 months
what is iatrogenic thyrotoxicosis?
pu/pd/pp, hyperactivity, & tachycardia - reevaluate treatment
what is the prognosis of hypothyroidism?
excellent
T/F: euthyroid sick syndrome can complicate the diagnosis of hypothyroidism
TRUE
what is seen at birth in a dog with congenital hypothyroidism?
disproportionate dwarfism
what treatment is done for a dog with hypothyroidism that is in a myxedema coma?
T4 must be given IV
what is the classic case presentation of a dog with diabetes mellitus?
middle aged dog that is pu/pd/pp, weight loss, cataracts (blindness)
what is the etiology of diabetes mellitus?
immune mediated destruction of the pancreatic islet cells (less common - severe pancreatitis)
what are predisposing factors for dogs with diabetes mellitus?
obesity, hyperadrenocorticism, steroid administration, & pregnancy
what clinical signs are seen in a dog with DKA?
vomiting, inappetance, lethargy, & dehydration
what initial screening is done for diagnosing diabetes mellitus?
CBC, chem - persistent hyperglycemia, increased ALP, hypercholesterolemia, & pre-renal azotemia if DKA - decompensation of DM set off by concurrent diseases (infection, pancreatitis)
after initial testing, what diagnostics are done for diabetes mellitus?
serum fructosamine - gives bg over 1-3 weeks
what treatment is done for stable diabetic dogs?
long acting SQ insulin ever 12 hours, diabetic specific diet at home monitoring - at home bg checks, fructosamine, bg curves, & clinical parameters
what treatment is done for a dog in DKA?
IV fluids, regular insulin CRI, & treatment of concurrent disease
what are some common complications associated with diabetes mellitus?
secondary infections - cystitis, dermatitis, cataracts (affect 80% dogs in first year of diagnosis)
what is the prognosis for a dog with diabetes mellitus?
good if the owner is able to provide care
what is the classic case presentation of a cushing’s dog?
middle aged dog - pu/pd/pp/panting, pot belly appearance, truncal alopecia, hepatomegaly, & muscle weakness
what are the etiologies of cushing’s disease?
pituitary microadenoma (PDH), adrenal tumors, or iatrogenic - PDH most common, adrenal tumors more likely if > 20 kg
what initial screening is done when working up a suspected cushing’s dog?
CBC - stress leukogram, mature neutrophilia, monocytosis, lymphopenia, eosinopenia, & thrombocytosis chem - ALP elevation, hypercholesterolemia urinalysis - isosthenuria +/- proteinuria
after initial screening, what diagnostics are done for a possible cushing’s dog?
ACTH stim - only for iatrogenic LDDST, urine cortisol:creatinine, & always treat non-adrenal illnesses before pursuing diagnostics/treatment
what differentiating test for PDH vs AT done is done after the diagnosis of hyperadrenocorticism?
abdominal ultrasound, HDDST, endogenous ACTH
what treatment is used for cushing’s dogs due to PDH?
trilostane - others include mitotane & rare surgery
what treatment is used for cushing’s dogs due to an adrenal tumor?
surgical adrenalectomy is the treatment of choice due to the likelihood of malignancy (carcinoma) meds - trilostane/mitotane
what monitoring is recommended for cushing’s dogs?
clinical signs & ACTH stim test
what is the prognosis for cushing’s dogs from PDH? what about AT?
PDH - good if medically managed AT - fair to poor (can invade caudal vena cava & met)
what are common sequelae seen with cushing’s dogs?
secondary infections, hypertension, & proteinuria
T/F: stress can cause false positive test results for ACTH stimulation & LDDST for suspect cushing’s dogs
TRUE
what is the classic case presentation of an addison’s dog?
young to middle aged usually female dog - poodles & purebreds - waxing/waning signs that worsen with stress, vague gi signs, weight loss - can progress to addisonian crisis (bradycardia, hypotension, vomiting, diarrhea, lethargy)
what is the etiology of addison’s disease?
immune-mediated destruction of the adrenal cortex, iatrogenic from long term steroid use that isn’t tapered, or with mitotane/trilostane therapy
what are the two forms of addison’s disease? how are they different?
typical - glucocorticoid & mineralocorticoid deficiency atypical - just glucocorticoid deficiency
what is the only definitive test for addison’s disease? what other diagnostics are done alongside it?
definitive - ACTH stim others - cbc, chem, baseline cortisol, & UA
what is seen on cbc, chem, & urinalysis in a suspect addison’s dog?
CBC - lack of a stress leukogram in a sick dog, eosinophilia, lymphocytosis, normocytic normochromic non-regenerative anemia typical chem - decreased Na:K ratio <27, hyponatremia, hyperkalemia, hypoglycemia, metabolic acidosis, hypercalcemia, hypoalbuminemia atypical chem - all changes except for electrolyte derangements UA - isosthenuria
what treatment is used for an addisonian crisis?
isotonic iv fluid resuscitation, treat life threatening hyperkalemia, dex SP IV until diagnoss is confirmed before starting mineralocorticoids
what is the long term treatment used for addison’s patients?
physiologic steroids, DOCP injections
for addison’s patients on DOCP, what needs to be monitored?
monitor lytes on days 14 & 25 to determine dosage/dosing interval
what is the prognosis for addison’s disease?
excellent with treatment
