Companion Animals

Hyperthyroidism in Cats: Welfare and Treatment

Feline hyperthyroidism is the most common hormonal disorder in older cats, causing significant welfare impacts if left untreated.

Key Facts

Affects approximately 10% of cats over 10 years of age
Caused by benign tumour growth in the thyroid gland
Symptoms include weight loss despite increased appetite, hyperactivity, and vomiting
Can lead to heart disease and kidney failure if untreated
Treatment options include medication, radioactive iodine, surgery, and dietary therapy

Welfare Considerations

Undiagnosed hyperthyroidism causes chronic discomfort including nausea, agitation, and progressive organ damage. Early diagnosis through routine blood testing in senior cats significantly improves welfare outcomes. Radioactive iodine therapy is considered the gold standard treatment, with a cure rate above 95% and minimal side effects. Lifelong medication is effective but requires daily dosing, which can be stressful for cats and owners.

What You Can Do

Schedule annual blood tests for cats over 8 years old
Recognise early signs: weight loss with good appetite, restlessness, vomiting
Discuss all treatment options with your vet including radioactive iodine
Ensure cats on medication are monitored for kidney function
Support research into thyroid disease prevention in cats