Feline hyperthyroidism is the most common endocrine disorder in older cats, and long-term management quality significantly affects the welfare of the millions of cats affected globally.
Hyperthyroidism management quality has a direct and sustained impact on the welfare of affected cats. Untreated disease causes a prolonged deterioration in quality of life: the hypermetabolic state produces constant hunger alongside wasting, cardiovascular stress that may manifest as distress, and hypertension causing ocular damage and neurological signs. Treatment selection significantly affects long-term welfare: radioactive iodine offers a single curative treatment avoiding daily medication stress, but requires a period of clinic isolation that is itself stressful for cats. Daily oral medication is effective when tolerated but imposes repeated handling stress in cats who resist pilling. Transdermal gel improves compliance in difficult-to-medicate cats. The emergence of concurrent CKD after treatment restoration of normal blood pressure requires careful monitoring and management to avoid trading one welfare problem for another. Proactive monitoring of blood pressure, thyroid levels, and kidney function optimizes long-term welfare outcomes.