Companion Animals

Cat Hyperthyroidism Dietary Management

Dietary management of feline hyperthyroidism using iodine-restricted food offers a medication-free alternative for some cats.

Key Facts

Thyroid hormone synthesis requires iodine - restricting dietary iodine reduces production
Hills y/d is the only licensed iodine-restricted diet for feline hyperthyroidism in the UK
The diet must be fed exclusively - any other food or treats removes the benefit
Serum T4 normalises in most cats on exclusive y/d feeding within 4-8 weeks
Not suitable for cats that cannot be fed exclusively or with concurrent illness

Welfare Considerations

Dietary management of hyperthyroidism avoids the stress of twice-daily medication administration for cats and owners. However, the requirement for exclusive feeding is challenging in multi-cat households or cats that roam outdoors. The welfare benefit of medication-free management must be weighed against the management challenges for individual cats.

What You Can Do

Discuss dietary management as an option with your vet for newly diagnosed hyperthyroid cats
Ensure all family members understand the exclusive feeding requirement
Monitor T4 and body weight regularly to confirm dietary control