Hyperthyroidism affects the majority of cats over 12 years old and causes significant systemic illness if untreated. Early diagnosis and appropriate treatment dramatically improve welfare and lifespan.
Feline hyperthyroidism is a condition where the gap between identified disease and treatment initiation is measured in months of unnecessary suffering. A hyperthyroid cat experiences the physiological equivalent of being permanently revved at high RPM — metabolically hyperactive, unable to maintain weight despite voracious eating, and at risk of cardiovascular crisis. Owners who attribute these changes to normal aging delay treatment that would rapidly restore quality of life. Annual thyroid screening for cats over seven years and prompt treatment of confirmed hyperthyroidism are straightforward welfare interventions with dramatic outcomes.