Acromegaly in Cats: Welfare and Insulin-Resistant Diabetes

Feline acromegaly is caused by a growth hormone-secreting pituitary tumour, causing insulin-resistant diabetes and progressive organomegaly with significant welfare implications.

Key Facts

Acromegaly in cats results from a functional pituitary adenoma producing excess growth hormone — it predominantly affects male cats over 8 years
Clinical signs include insulin-resistant diabetes mellitus, broadened facial features, enlarged paws, and progressive organomegaly
Diagnosis requires IGF-1 measurement (usually markedly elevated) confirmed by pituitary CT or MRI
Radiation therapy targeting the pituitary tumour can achieve remission of growth hormone excess in a significant proportion of treated cats

Welfare Considerations

Acromegaly welfare management involves addressing both the consequences of excess growth hormone (insulin resistance, organomegaly, joint enlargement causing arthritis) and the pituitary tumour causing them. Uncontrolled acromegalic diabetes causes all the welfare consequences of poorly regulated diabetes mellitus, compounded by progressive tissue changes from GH excess. Radiation therapy requires specialist referral but can substantially improve welfare by reducing GH levels, improving insulin sensitivity and slowing tumour progression. Without radiation, insulin requirements escalate progressively as the tumour grows.

What You Can Do

Test IGF-1 in any diabetic cat with insulin resistance — elevated IGF-1 above 1000 nmol/L is highly suggestive of acromegaly
Discuss radiation therapy referral with a veterinary specialist — outcomes are favourable and can reduce long-term welfare burden
Monitor for acromegaly-associated arthritis and implement appropriate analgesia for affected joints
Adjust insulin dose frequently in early management — dose requirements change substantially as GH levels fluctuate