Feline hyperthyroidism is the most common endocrine disorder in older cats, and treatment choices have significantly different welfare implications for affected animals.
Hyperthyroidism treatment choice involves balancing welfare considerations for both the cat and the owner. Untreated hyperthyroidism causes cardiac strain, hypertension, and systemic effects that progressively impair welfare. Radioactive iodine provides a curative single treatment with minimal procedural stress, making it the welfare-optimal choice when available and accessible. Daily medication is a viable alternative but requires long-term owner commitment to avoid breakthrough hyperthyroidism.