Hill’s Pet Nutrition announced this past week that they have introduced a new diet to treat hyperthyroidism in cats. This low iodine diet – called Hill’s Prescription Diet y/d Feline Thyroid Health – is designed to control hyperthyroidism without the use of traditional medications such as methimazole or other treatments such as radioactive iodine therapy or surgical removal of the thyroid gland. Hyperthyroidism is a common disease of senior cats where the thyroid gland produces excessive thyroid hormone, causing problems such as weight loss despite a good appetite, diarrhea and/or vomiting, increased thirst, hyperactivity, and poor skin and coat condition. The company released several research studies at the American College of Veterinary Internal Medicine meeting in Denver, CO in June showing that carefully limiting the iodine content of cat food results in normal levels of thyroid hormone. In most of the treated cats, blood thyroid hormone levels returned to normal within 3 weeks of starting the new diet and no adverse effects were noted. The Cat Hospitals’ own Dr. Susan Little took part in an expert panel meeting on the new diet in April of this year and helped develop some of the educational materials.