Companion Cat Hyperthyroidism Management

Hyperthyroidism is the most common hormonal disorder in older cats. Early diagnosis and effective treatment preserve quality of life and prevent secondary organ damage.

Key Facts

Hyperthyroidism affects approximately one in ten cats over 10 years of age
The condition causes weight loss despite increased appetite, along with restlessness and increased thirst
Untreated hyperthyroidism causes hypertension, heart disease, and kidney damage as secondary conditions
Radioactive iodine treatment is curative in over 95% of cases with minimal welfare impact during treatment
Medical management with methimazole controls but does not cure the condition
Dietary iodine restriction through specialist prescription food offers a non-medical management option

Welfare Considerations

Hyperthyroidism causes significant welfare compromise in affected cats through weight loss, restlessness, cardiovascular strain, and secondary organ damage. Early diagnosis through routine senior blood screening allows treatment before serious secondary damage occurs. Radioactive iodine treatment offers cure with excellent welfare outcomes for most cats. The welfare case for regular senior cat screening — enabling early detection and treatment of hyperthyroidism and other common conditions — is compelling.

What You Can Do

Schedule annual blood thyroid screening for cats over 9 years of age
Discuss treatment options with your vet if your cat is diagnosed with hyperthyroidism
Monitor for signs including weight loss with good appetite and increased vocalisation in older cats
Consider radioactive iodine treatment as the most welfare-positive curative option
Support your vet in managing post-treatment kidney assessment, as treatment can unmask concurrent kidney disease