Feline hyperthyroidism is the most common endocrine disease in older cats, and the choice between medical, dietary, and surgical management has significant welfare implications.
Untreated hyperthyroidism causes progressive heart disease, hypertension, and systemic deterioration causing genuine suffering in affected cats. Treatment choice significantly affects welfare quality: I-131 radioiodine provides a permanent cure with minimal ongoing welfare cost but requires temporary boarding; methimazole requires twice-daily medicating that some cats strongly resist causing daily stress; dietary management requires strict enforcement that multi-cat households cannot easily maintain.