Feline hyperthyroidism is the most common endocrine disorder in older cats. Understanding the welfare implications of different management options — radioactive iodine, surgery, medication, and diet — helps owners and vets make optimal decisions.
Hyperthyroidism welfare management requires balancing treatment efficacy, welfare cost of the treatment itself, and long-term quality of life. Untreated hyperthyroidism causes progressive deterioration and significant suffering. Radioactive iodine is the gold standard — curative, safe, and requiring only a short hospitalization — but is not universally accessible or affordable. Medical management with methimazole is effective but requires stressful twice-daily pill administration for life. Iodine-restricted diet is non-invasive but constraining. The welfare decision involves weighing each option's burden against the cat's prognosis, concurrent conditions, and owner capacity. All options are preferable to no treatment.