Feline hyperthyroidism is the most common endocrine disease of older cats, causing significant welfare harm if undiagnosed. Treatment options including radioactive iodine offer excellent welfare outcomes.
Feline hyperthyroidism causes progressive welfare harm through weight loss despite hunger, cardiovascular stress, and secondary organ damage. Cats with advanced untreated hyperthyroidism experience the paradox of increased appetite and concurrent weight loss - eating normally but losing body condition. Secondary heart disease causes respiratory distress. Early diagnosis through annual blood testing from age 10 allows treatment before significant welfare deterioration. Radioactive iodine treatment offers the best welfare outcome - a single treatment with no ongoing medication requirement restores normal thyroid function. Owners aware of the signs can seek diagnosis earlier, preventing months of avoidable welfare decline.