Feline hyperthyroidism is the most common endocrine disorder in older cats, and while highly treatable, long-term management requires careful monitoring to prevent complications.
Untreated hyperthyroidism causes cats to feel continuously anxious and restless while losing weight despite voracious eating - a distressing physiological state. Hypertension causes headaches and can lead to sudden blindness. Medical management requires daily pilling that many cats find stressful. Radioactive iodine, when available, offers the most humane long-term option by providing permanent cure without ongoing medication. Regular monitoring prevents dangerous complications and preserves quality of life.