Hyperthyroidism is the most common endocrine disease in older cats. Effective management dramatically improves welfare, but treatment choice affects quality of life during and after treatment.
Hyperthyroid cat welfare depends critically on early diagnosis and appropriate treatment. Untreated hyperthyroidism causes progressive suffering through weight loss, chronic anxiety from elevated metabolism, and organ damage. Yet many cats are diagnosed late because early signs are subtle and owners may misinterpret the increased activity and appetite as healthy changes. Annual thyroid checks in cats over 9 years old enable early intervention. Treatment choice should balance efficacy, welfare during treatment, and individual cat and owner circumstances.