Companion Animals

Cat Hyperthyroidism Dietary Management

Iodine-restricted diets offer an alternative to medication or surgery for managing feline hyperthyroidism, but require careful implementation and monitoring.

Key Facts

Feline hyperthyroidism affects approximately 10% of cats over 10 years
Iodine-restricted diets (e.g. Hill's y/d) can normalise thyroid hormone levels
The diet must be fed exclusively - even small amounts of other food interfere
Medication (methimazole), radioactive iodine, or surgery are alternatives
Regular thyroid level monitoring is essential with all treatment methods

Welfare Considerations

Uncontrolled hyperthyroidism causes a range of distressing symptoms including weight loss, vomiting, hyperactivity, and heart problems. Dietary management requires strict compliance, which can be challenging in multi-cat households.

What You Can Do

Have senior cats (over 10 years) screened annually for hyperthyroidism
Discuss all treatment options with your vet including dietary management
If using dietary therapy, ensure complete exclusion of other food sources
Monitor weight, appetite, and behaviour closely during treatment
Schedule regular thyroid level checks - at least every 6 months