Feline hyperthyroidism is the most common endocrine disease in older cats. Understanding treatment options and long-term welfare management improves outcomes.
Hyperthyroid cats typically experience dramatic welfare improvement after treatment — the ravenous hunger, hyperactivity, and cardiovascular stress of uncontrolled disease give way to normal appetite, calmer behaviour, and improved cardiovascular function. The welfare challenge is in the treatment period: some cats resist daily medication, causing ongoing stress for both cat and owner; the boarding required for radioactive iodine can be stressful for some individuals; and the unmasking of underlying kidney disease after treatment represents a difficult management transition. Regular monitoring of thyroid levels, blood pressure, and kidney function is essential for long-term welfare optimisation. The excellent prognosis for treated hyperthyroid cats makes this one of the more welfare-positive diagnoses in geriatric feline medicine.