Hyperthyroidism is the most common endocrine disorder in middle-aged and older cats, causing significant suffering if untreated but responding well to a range of available treatments.
Hyperthyroidism in cats causes a constellation of welfare impacts: hunger without satiety despite constant eating, restlessness and inability to settle, vomiting, diarrhea, and progressive cardiac enlargement. Affected cats may show signs of anxiety and discomfort that owners often misattribute to aging. The good news is that hyperthyroidism is highly treatable. Radioactive iodine, anti-thyroid medication, surgical thyroidectomy, and dietary iodine restriction all offer viable paths to remission. Early diagnosis through routine screening of senior cats and prompt initiation of treatment significantly improves welfare outcomes and long-term prognosis.