Hypothyroidism Flashcards
Hypothyroidism
↓ production of T4 and T3
Primary most common
Also caused by idiopathic thyroid atrophy and lymphocytic thyroiditis
Signalment of hypothyroidism
Labs and dobermans
Middle-aged Salukis (lymphocytic thyroiditis)
CS of hypothyroidism
Depression, leth, Chr derm, hyperpig
Poor wound healing, KCS, uveitis
Weight redistribution, alopecia, bradycardia
Myxedema, etc.
Lab findings associated with hypothyroidism
N/N non regenerative anemia
Fasting hypercholesterolemia
Hypertriglyceridemia
Thyroid levels
Total T4 low
Free T4 low
TSH high
Why is it important to make an accurate dx prior to therapy?
Greyhounds and other sight-hounds have natural lower T4 and Free T4 and TSH will be normal
Euthyroid sick
Concurrent illness
Cortisol (cushings) will ↑ T4
Meds alter: glucos, sulfa-drugs, phenobarb
Thyroiditis
Anti-thyroglobulin abs
Thyroid hormone auto-abs: anti-T4 and anti-T3 (cross react with Free T4 molecules in radioimmunoassays)
Tx of hypothyroidism
Levothyroxine (max dose 0.8 mg BID)
Thyro-tabs canine
Liquid levo
Monitoring for hypothyroidism
Give meds 1m
Serum Total T4
4-6hr after morning dose
Titrate dose low to mid-range level
Myxedema coma
Emergency!
Hypotensive, bradycardic, hypothermic, stuporous
How to tx myxedema coma
Correct abnormalities and support
IV levothyroxine
