Feline Flash Notes - Hyperthyroidism

Question 1

what’s the number one endocrine disease of cats?

Answer 1

hyperthyroidism

Question 2

what is the classic case presentation of a cat with hyperthyroidism?

Answer 2

weight loss, polyphagia, hyperactive, poor body condition, unkempt fur, systolic murmur, palpable thyroid gland, concurrent HCM, hypertension, & renal failure

Question 3

how is feline hyperthyroidism diagnosed?

Answer 3

total T4 is diagnostic in 95% of cases, but if normal, free T4 - palpation with 30% unilatral & 70% bilateral

Question 4

what is the classic signalment of cat affected by hyperthyroidism?

Answer 4

95% over 8 years old - no sex predilection

Question 5

what is the purpose of a technetium scan for feline hyperthyroidism?

Answer 5

confirms the diagnosis, identifies tumor location, ectopic thyroid, & metastasis

Question 6

what is the treatment of choice for feline hyperthyroidism?

Answer 6

radioactive iodine therapy

Question 7

what is the risk of surgical intervention for treating hyperthyroidism?

Answer 7

risk of hypoparathyroidism resulting in life threatening hypocalcemia

Question 8

what is the medical treatment used for hyperthyroidism?

Answer 8

methimazole - life long treatment & many side effects

Question 9

what are four common concurrent problems with hyperthyroidism?

Answer 9

cardiac disease (HCM), systemic hypertension, renal failure, & hypokalemia (neck ventroflexion & weakness)

Question 10

what can be unmasked when a hyperthyroid cat starts methimazole treatment?

Answer 10

kidney failure/disease

Question 11

what is a thyroid storm?

Answer 11

intense sympathetic discharge in response to a stressful event or restraint causing severe tachycardia/bradycardia & severe systemic hypertension

Question 12

what is apathetic feline hyperthyroidism?

Answer 12

less than 10% of cases, but cats present with depression, weakness, & anorexia

Question 13

what side effects are associated with methimazole?

Answer 13

vomiting, anorexia, pruritus of the head/neck, & depression

Question 14

what is the most common pathology associated with feline hyperthyroidism?

Answer 14

benign thyroid neoplasa or adenomatous hyperplasia, less than 2% are thyroid carcinomas

Question 15

what is the prognosis of a hyperthyroid cat with unmasked kidney failure with treatment?

Answer 15

good short term but poor long term prognosis