thyroid

Question 1

primary hypothyroidism types

Answer 1

congenital- cretinism, rare
acquired- lymphocytic thyroiditis (heritable in beagles, borzoi)
idiopathic thyroid atrophy

Question 2

hypothyroidism C/S

Answer 2

rare, older dogs
nonspecific signs, lethargy, obesity w normal appetite, derm signs: alopecia, dull hair, seborrhea, pyoderma, demodex, otitis externa

neuropathy- vestibular, laryngeal paralysis, megaesophagus
bradycardia, muscle atrophy, corneal lipid
myxedema

Question 3

congenital hypothyroidism

Answer 3

stunted growth starting 3-8wks
lg head, short neck, short limbs
delayed dental development
goiter

Question 4

hypothyroid diagnosis

Answer 4

hypertriglyceridemia, high cholesterol
TT4 high for first screening (most sensitive)
free T4 more Sp, accurate but $$$
TSH- best with low T4

Question 5

fluctuations in thyroid hormone

Answer 5

different normal ranges for different breeds
medications, systemic illness (euthyroid sick)
other diseases (cushings, DM, addisons, CKD, hepatopathy, CHF)

Question 6

hypothyroid tx

Answer 6

levothyroxine 0.02mg/kg q12
recheck 4-6wks later
max 0.8-1mg q12 dose

Question 7

hyperthyroidism

Answer 7

older cats, indoor
C/S- weight loss, PP, murmur

increased metabolism, GFR. muscle contraction, increase HR, weakness, increased RR

Question 8

heart disease w hyperthyroid

Answer 8

tachycardia, gallops, systolic murmur
HCM-> CHF
hypertension

Question 9

hyperthyroid and CKD

Answer 9

same age
hyperthyroid masks CKD (increased GFR), also leads to kidney damage

Question 10

hyperthyroid dx

Answer 10

CBC- stress response
chem- liver enzyme increase (ALT/ALP), high P, azotemia
low K
silent UTI
test TT4, confirm w FT4

Question 11

hyperthyroid tx

Answer 11

methimazole-> inhibits thyroid peroxidase
2.5mg SID, BID PO or TD
recheck in 3wks, then q3-6m

I131- IV or SQ, expensive

tx CKD first if azotemic, echo for heart, TXR

sx, y/d