Hyperthyroidism is the most common hormonal disorder in older cats, causing chronic welfare compromise that responds well to treatment with multiple effective options available.
Hyperthyroidism causes insidious welfare compromise — cats lose significant weight, their heart rate accelerates, they become hypertensive, and many experience anxiety-like behavioral changes. Yet because they may initially appear more active, the condition can be misread as a cat becoming livelier rather than sicker. Treatment is highly effective for most cats. Medication controls the condition but requires twice-daily administration. Radioactive iodine, while more expensive upfront, is curative with minimal side effects and avoids years of daily medication stress for cat and owner. Discussing treatment options openly with an internist or specialist ensures each cat receives the most welfare-positive approach for their individual situation.