Feline Hyperthyroidism: Updated Welfare Management 2025

Key Welfare Facts

Hyperthyroidism is the most common endocrine disorder in older cats, affecting 1 in 10 cats over 10 years.
Excess thyroid hormone causes weight loss, hypertension, heart disease, and chronic restlessness and anxiety.
Medical management with methimazole or carbimazole controls hormone levels effectively but requires lifelong dosing.
Radioiodine treatment provides permanent cure in over 95% of cases with a single treatment.
Thyroid surgery achieves permanent cure but carries anaesthetic and hypocalcaemia risks in elderly cats.
Iodine-restricted diet as sole therapy is effective only with complete dietary compliance which is often impractical.

Welfare Assessment

Hyperthyroidism welfare management in 2025 increasingly favours definitive treatment with radioiodine where available. Working with a specialist to choose the optimal treatment for each individual cat's health status and lifestyle maximises long-term welfare.

What You Can Do

Seek veterinary assessment for any older cat showing weight loss with increased appetite or restlessness
Discuss radioiodine treatment as the definitive welfare-optimal solution where access permits
Monitor blood pressure alongside thyroid status as hypertension causes independent welfare compromise
Ensure regular monitoring of renal function as hyperthyroidism treatment can reveal underlying kidney disease