Hyperthyroidism is the most common endocrine disease of older cats, causing significant welfare impacts that respond well to treatment when diagnosed promptly.
Hyperthyroid cats experience significant chronic welfare compromise including the paradox of voracious appetite with progressive weight loss and muscle wasting, anxiety and restlessness from excess thyroid hormone, and cardiovascular strain causing hypertension and heart disease. Many owners attribute signs to normal aging and delay diagnosis, allowing prolonged suffering. All treatment options can restore good quality of life when implemented appropriately. Access to radioactive iodine therapy, while not universally available, provides the most complete welfare solution through permanent cure.