Feline hyperthyroidism is the most common endocrine disorder in older cats, and long-term management with radioiodine, medication or dietary therapy can restore excellent quality of life.
Hyperthyroidism causes significant suffering including restlessness, muscle wasting, vomiting, diarrhoea and cardiac complications. Untreated, it causes progressive deterioration. However, all three primary treatment options can achieve excellent control, and many treated cats return to full health.