Thyroid Disease

Question 1

What are the two thyroid hormones?

Answer 1

Thyroxine (T4)
Triiodothyronine (T3)

Question 2

What species is most commonly affected by hyperthyroidism?

Answer 2

Felines

Question 3

What are the 8 clinical signs of Hyperthyroidism?

Answer 3

1. Weight loss with ravenous appetite (polyphagia)
2. Thyroid nodule (“slip”)
3. Hyperactivity
4. Vomiting
5. Increased vocalization
6. Tachycardia
7. Hear murmur or gallop
8. Thyrotoxic cardiomyopathy

Question 4

What is the preferred test for Thyroid disease (hyperthyroidism and hypothyroidism)?

Answer 4

Serum Total T4 (>40ug/dl)

Question 5

What are the 4 types of treatment options and examples of each for Hyperthyroidism?

Answer 5

1. Medical:
   - Oral or transdermal Methimazole - tx of choice for initial therapy
   
   • Possible side effects, which include facial excoriations
2. Surgical: Thyroidectomy
   - Usually bilateral dz requiring bilateral thyroidectomy
3. Radioactive Iodine:
   - I-131; Single dose, requires hospitalization, usually for several days to weeks, depending on state radiation laws
4. Dietary Therapy:
   - Iodine-restricted diet reduces production of T3 and T4 (controversial)

Question 6

What is Hypothyroidism?

Answer 6

Thyroid glands in the neck produce insufficient levels of thyroid hormone

Question 7

What is the treatment for hypothyroidism?

Answer 7

Oral Levothyroxine AKA Synthryoid™, Soloxine™

Question 8

What species does hypothyroid most often affect?

Answer 8

Canines

Question 9

What is the name of the disease in dogs that has similar signs to hypothyroidism?

Answer 9

Euthyroid sick syndrome

Question 10

What are the 6 clinical signs of Hypothyroidism?

Answer 10

1. Weight gain, obesity
2. Lethargy
3. Alopecia - often bilaterally symmetric over the lateral trunk, tail, + ventral thorax
4. Heat-seeking
5. Muscle weakness
6. Skin disease - pyoderma, hyperkeratosis, seborrhea, hyperpigmentation