Hyperthyroidism is the most common endocrine disorder of older cats, and choosing the right long-term treatment significantly affects quality of life and welfare outcomes.
Untreated hyperthyroid cats suffer progressive weight loss, muscle wasting, hypertension, and cardiac disease despite voracious appetite - a welfare paradox of eating well but deteriorating rapidly. Each management option carries different welfare implications: daily pilling is stressful for many cats long-term; radioactive iodine requires prolonged isolation post-treatment; surgery carries anesthetic risk. Individualized treatment planning based on the cat's temperament, concurrent health status, and owner capabilities maximizes both welfare and compliance.