Hyperthyroidism is the most common hormonal disorder in older cats and significantly compromises welfare if undiagnosed or inadequately treated.
Hyperthyroid cats experience significant welfare compromise including chronic muscle wasting, cardiac arrhythmias, hypertensive organ damage and persistent hunger despite adequate feeding. The restlessness and vocalisations of hyperthyroid cats at night are a recognised welfare indicator of the disease state. Treatment dramatically improves welfare within weeks: weight regain, reduced heart rate, calmer behaviour and improved coat condition. Radioactive iodine provides permanent cure without ongoing medication stress. Early detection through annual blood screening from 9 years of age prevents prolonged unnecessary suffering.