Hyperthyroidism is the most common endocrine disorder in older cats, causing significant welfare impacts if untreated. Understanding treatment options helps owners make welfare-informed decisions.
Untreated feline hyperthyroidism causes significant ongoing suffering: affected cats are restless, lose weight despite increased appetite, develop heart disease and experience hypertension-related complications including potential blindness. The welfare case for treatment is clear. The treatment choice involves welfare trade-offs: radioactive iodine is curative and drug-free but requires hospitalisation and temporary separation from owners; medical management requires twice-daily pilling which causes stress for many cats and owners and has variable compliance. Veterinary guidance should explicitly address the welfare implications of each option for the individual cat's circumstances, including temperament and owner capacity.