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Treating Feline Hyperthyroidism with Reduced Iodine Hill's Y/D Diet

A new safe and effective way to manage this common disease in cats


Y/D Food - Courtesy Hill's Prescription Pet Food

Y/D Food

Courtesy Hill's Prescription Pet Food

Hyperthyroidism in Cats

The thyroid gland is responsible for producing thyroid hormones that control metabolism, calcium balance and other functions throughout the body. When the thyroid gland makes too much hormone (usually due to a non-malignant tumor), this creates a condition called hyperthyroidism. The excess hormones cause problems throughout the body, including weight loss, heart problems, vomiting, and more.

Traditional Treatment Options

For years, veterinarians have had three treatment options for feline hyperthyroidism: oral medication (methamizole), thyroid removal surgery, or radioactive iodine (I-131) treatment. Each treatment option afforded different pros and cons, including costs and health risks and benefits.

New Treatment Option for Feline Hyperthyroidism

We now have a new way to manage this disease: food. This option provides a non-invasive, easy way to manage this disease for many senior hyperthyroid cats, including those who are pre- or early stages of kidney disease.

Introducing Y/D Feline

Hill's Pet Foods has been a leader in prescription foods; foods designed to manage various conditions, such as diabetes, kidney disease and urinary health for years. The "hyperthyroidism food" is Y/D, and will be available through veterinarians starting on September 1, 2011.

How Does This Food Work?

The food is not medicated. How it works is simple: the thyroid needs iodine to make thyroid hormones. By reducing the amount of dietary iodine, the diseased thyroid does not have the necessary ingredient to 'overproduce' thyroid hormones.

This diet has been in development at Hill's for over 10 years. Hyperthyroid cats have been successfully managed - resuming normal thyroid hormone levels - on this diet alone1. Clinical signs resolved, and blood values of thyroid hormone have remained normal on this diet.

Since the majority (~98%) of hyperthyroid cases2 involve a benign growth, the diseased thyroid tissue does not create additional damage in the body while on this diet.

Why Did It Take 10 Years To Become Available?

The amounts of iodine in this diet are very small - 0.32ppm - parts per million. The levels of iodine in the environment and food-processing equipment will easily 'cross-contaminate' this diet at the factory. Hill's has spent a considerable amount of time developing ways to purify the processing environment and testing the food at various stages of creation to ensure the iodine levels are as intended.

I Have A Multi-Pet Household - Can I Feed This Food?

Yes. Ideally, the hyperthyroid patient should be fed separately. The amounts of iodine in this diet are very small, so 'contamination' by eating other diets higher in iodine will negate the benefits of this diet.

Studies by Hill's have shown that non-hyperthyroid patients may also eat this diet, with the recommendation of a regular food 'treat' offered daily to ensure adequate levels of iodine.

My Cat is Currently on Thyroid Medication - Can I Feed This Food?

Yes. Most cats transition off of the medication (methimazole) and on to the food over a period of 7 days. Some cats may need longer - over a period of weeks.

Related: Transitioning existing hyperthyroid patients (Chart Graphic / Hill's)

How Do I Get This Food for my Cat?

This food is a prescription diet, available only through your veterinarian, for cats diagnosed with hyperthyroidism. Until September 30, 2011, Hill's is offering free "Starter Packs" to veterinarians for their hyperthyroid patients.

Each Starter Kit includes:

  • 4-lb. bag of y/d Feline Dry
  • Four 5.5-oz. cans of y/d Feline Canned
  • y/d Feline Pet Owner Guide
  • Reusable can lid
  • Measuring cup (8 oz.)
  • 1.5-liter food storage container

Speak to your veterinarian about learning more about this offer. Veterinarians, contact your Hill's rep or call 1-800-548-VETS (8387) for more info.

Y/D Feeding Trials1 - Teleconference with Hill's Veterinarians, August 2011, Hill's research abstracts
Hyperthyroid cases2 - Hyperthyroidism in Cats

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