Hyperthyroidism

Question 1

Pathophysiology

Answer 1

Excessive production of thyroxine (T4) and triiodothyronine (T3)

Results in increased

• MBR
• HR
• glucose usage
• GI motility

Question 2

Main aetiology

Answer 2

Thyroid tumour

• functional adenoma in cats
• carcinoma in dogs

Question 3

Other factors influencing development (2)

Answer 3

Excessive iodine exposure

Fish and liver diets

Question 4

Conditions secondary to hyperthyroidism (3)

Answer 4

Hypertension
HCM
CRF

Question 5

Clinical signs (10)

Answer 5

Increase appetite
Weight loss
Hyperactivity
Hypertension
Tachycardia
Arrhythmia
Murmur
Goitre
Low stress tolerance
Skin and coat changes

Question 6

Diagnosis (7)

Answer 6

Hx/cs/exam
Haem
- +pcv/+hgb/+rbc count and size
Biochem
- + liver enzymes / KP to check for CRF
Blood glucose and urinalysis
- rule out DM / check for CRF
Thyroid function tests
TSH test
- decrease due to compensation