Feline hyperthyroidism is the most common hormonal disease of older cats and requires long-term management with significant welfare implications if left untreated or poorly managed.
Feline hyperthyroidism causes chronic welfare harm through multiple mechanisms: weight loss despite hunger, hypertension causing headache-equivalent discomfort, heart changes causing exercise intolerance and eventually heart failure. Untreated hyperthyroidism is progressive and ultimately fatal. Treatment is highly effective - radioactive iodine provides permanent cure in approximately 95% of cases. Medication management requires daily tablet or spot-on administration that some cats find stressful. The welfare goal is effective disease control with minimal treatment-related stress, monitored through regular veterinary assessment. Early diagnosis through senior health screening prevents prolonged untreated suffering.