Distribution of iodine content of 92 commercial cat foods (complete dry and canned foods) in μg/kg dry matter expressed as percentage.
“This food is so good at limiting iodine that if the (cat’s condition) is not improving, there’s an incredibly high chance that the cat is getting food somewhere else—even if the owner insists otherwise,” Bruyette says.
* Another theory implicates the large excess of iodine found in many cat foods. Humans can develop hyperthyroid disease from too ingesting much iodine; might cats do the same? Iodine is difficult and expensive to test for; instead, pet food makers routinely add extra, just to make sure that minimums are met. But how much is too much? So far, nobody knows, although Hill’s Pet Nutrition is taking advantage of this theory by producing an ultra-low-iodine food (see below under Treatments).
Iodine content of commercially-prepared cat foods. - NCBI
We can do a low-iodine diet - any here ever cook homemade cat food
Recently, the Hill's company introduced a new diet called Hill's Prescription Diet y/d Feline Thyroid Health. The diet is very iodine restricted. Iodine is necessary for the synthesis of thyroid hormone and so by depriving the cat of iodine, the thyroid cannot produce excessive amounts of thyroid hormone, and the condition comes under control. A caveat is that a cat on this diet can eat Hill's y/d. No other food can be eaten - no treats, no other brand food, and no people food.There is no medication in the food! Instead, the food is iodine reduced. The reason that this works is that the thyroid gland needs iodine in order to make thyroid hormone. So, if very little iodine is supplied, then the cat can't over produce thyroid hormone.After starting on e medication, he seems more picky with his dry food choice though he loves his Wellness Core chicken wet food. Have been changing his dry food for the third time now & would like to know whether should I feed him high or low protein food? He has an elevated liver & kidney values since the last blood test on Friday before starting on the medication. Most commercial food contains higher Iodine (fish oil & kelp), phospohrous, sodium selenite, carrageenan and Iodize salt. Is it alright for his condition? Is there any recommendation on the food? Is Wellness, Natural Balance & Evo good enough?There are a couple likely environmental factors that have led to this epidemic. Firstly, multiple studies have been done that have pointed to certain cat foods as risk factors for developing hyperthyroidism. The food offenders included fish for their high levels of polybrominated diphenyl ethers (PBDEs), which are a known endocrine and thyroid disruptor commonly found in fire retardant furniture, carpet and dust. Also referenced in the studies were known endocrine disruptors Bisphenol A (BPA) which is used to line some cans of cat food, and soy, which is a prevalent ingredient in many types of cat food. Humans are more than aware that soy, BPA and the PBDEs found in high concentrations fish are hormonal disruptors in our own systems. Some of these chemicals may be banned from human consumption in the United States, but are still widely used and imported in pet food. Even the FDA warns us, especially women of child bearing age and children, against consuming these same ingredients included in cat food. Another potential contributing factor to feline hyperthyroidism is iodine levels in food. Iodine is necessary for the thyroid to work properly, yet the levels of iodine in cat food widely vary. Iodine is highly prevalent in seafood, and too much iodine could result in an overactive thyroid. The pet food industry has acknowledged the correlation between iodine levels and hyperthyroidism in cats and many manufacturers have introduced low iodine prescription diets.