Hyperthyroidism is the most common endocrine disorder in older cats and requires ongoing management to maintain quality of life.
Hyperthyroid cats experience a range of welfare impacts that owners sometimes misinterpret as positive signs. Increased appetite and activity can mask the fact that the cat is metabolically stressed, losing muscle mass, and at risk of cardiac complications including hypertrophic cardiomyopathy. Untreated hypertension can cause retinal detachment and sudden blindness. Long-term welfare requires consistent treatment compliance, which is challenging for owners managing daily tablet administration. Transdermal gels applied to the ear flap offer improved compliance for resistant cats. The kidney complication after treatment requires careful monitoring since some cats need lower doses to preserve renal function. Early diagnosis and treatment substantially improves quality and length of life.