Feline Hypothyroidism

Question 1

What clinical signs are common in cats with hypothyroidism but not as common in dogs (and vice versa)?

Answer 1

• affected cats have mental dullness and decreased appetite, NOT bilateral symmetrical non pruritic alopecia like the dogs
• most common signs in the dog = obesity, and dermatological issues

Question 2

What are some clinical signs of feline congenital hypothyroidism?

Answer 2

• normal at birth, but changes noted by 2m
• failure to thrive, disproportional dwarfism
• severe recurrent constipation!
• broad head, short neck, round body, short legs
• abnormal haircoat, teeth development
• mentally dull
• neurologically abnormal
• abnormal haircoat

Question 3

How is feline hypothyroidism tested?

Answer 3

• total T4 alone is sensitive, but not specific enough (lots of other non-thyroid illness, drugs, etc.)
• free T4 not as helpful in cats vs dogs
• using cTSH to test for TSH level should be good in congenital vs secondary hypothyroidism
• rhTSH function test may be helpful

Question 4

What’s the most efficient and cost effective way to diagnosis feline hypothyroidism?

Answer 4

tT4 and cTSH
- can try scintigraphy or rhTSH if the results from above are equivocal

Question 5

How is feline hypothyroidism treated?

Answer 5

levothyroxine supplementation

Question 6

What’s the prognosis of acquired and congenital hypothyroidism in cats?

Answer 6

Acquired: with appropriate therapy, excellent prognosis
Congenital: guarded, pending underlying etiology and age at diagnosis

Question 7

How can imaging help with feline hypothyroidism diagnosis?

Answer 7

with congenital hypothyroidism, will see characteristic bone changes on radiographs