Hyperthyroidism in Cats: An Environmentally Based Epidemic
What is the history of feline hyperthyroidism? Is it genetic or environmental? Is it preventable?
Only recognized thirty-seven years ago, feline hyperthyroidism has quickly risen to the most common endocrine disorder in cats1 and is one of the most common feline disorders overall2. 1 in 10 cats over the age of ten is likely to develop hyperthyroidism, and is just as likely to succumb to it3.
What is Feline Hyperthyoidism?
Hyperthyroidism is a glandular disorder classified by excessive thyroid hormones in the blood. For the most part this is caused by enlarged lobes in the thyroid gland, called adenomatous hyperplasia. Very rarely, hyperthyroidism can be caused by thyroid carncinoma4. Hyperthyroidism is most common in older cats, but can also occur in younger cats, regardless of breed5. The thyroid gland regulates a cat’s metabolism which in turn regulates the speed of all the cat’s body functions including the heart, liver, gastrointestinal tract, kidneys, etc6. Cats with hyperthyroidism will exhibit signs of weight loss, an increase in appetite, and restlessness7.
How Did Hyperthyroidism Become an Epidemic?
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 hyperthyroidism8. The food offenders included fish for their high levels of polybrominated diphenyl ethers (PBDEs), which are a known endocrine and thyroid disruptor9 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 food10.
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 food11. 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 diets12.
How Can Hyperthyroidism Be Helped?
There are multiple approaches to treating feline hyperthyroidism. Two that directly treat the disorder include surgery to remove the thyroid gland, as well as a radioactive iodine that is injected or administered orally13. Holistic treatment includes adjusting the diet, using herbal supplements, digestive enzymes and flower essences14. Unfortunately, the symptoms of hyperthyroidism can mask kidney disease, and many cats suffer from both at the same time15.
In order to prevent as well as alleviate most of the symptoms of hyperthyroidism and kidney disease, we must look at the cat’s physiological and digestive needs. The mainstream diet that combats hyperthyroidism is a manufactured low iodine recipe that relies heavily on plant-based proteins and carbohydrates. Although it solves the iodine problem it deprives cats of the animal protein they require. Feeding a mammalian protein as opposed to an aquatic protein solves the iodine problem and satisfies the cat’s carnivorous nutritional needs. In fact, studies have shown that a high protein, low carbohydrate diet is optimal for cats with hyperthyroidism16.
1. Peterson, Mark. “Hyperthyroidism In Cats: What’s Causing This Epidemic of Thyroid Disease and Can We Prevent It?” Animal Endocrine Clinic, 2012.
2. Becker, Karen. “The One Feline Feeding Mistake That Can Lead to TWO Top Medical Conditions,” Mercola, 2013.
3. Becker, Karen. “Implant Radioactive Substance, Abandon for 7 Days – Could You Do This to Your Pet?” Mercola, 2016.
4. Diaz, Guillermo. “Feline Hyperthyroidism: What You Need to Know,” Feline Nutrition Foundation, 2012.
5. Salisbury, Kathleen S. “Hyperthyroidism in Cats,” Purdue University, 1991.
6. Pierson, Lisa A. “Feline Hyperthyroidism,” CatInfo.org, 2012.
7. “Thyroid Disorders in Cats and Dogs,” Only Natural Pet.
8. Peterson, Mark. “Hyperthyroidism In Cats: What’s Causing This Epidemic of Thyroid Disease and Can We Prevent It?” Animal Endocrine Clinic, 2012.
9. Becker, Karen. “Do You Feed Your Kitty This Favorite Food? 2 Reasons to Stop It Today,” Mercola, 2016.
10. Pierson, Lisa A. “Feline Hyperthyroidism,” CatInfo.org, 2012.
11. Peterson, Mark. “Hyperthyroidism In Cats: What’s Causing This Epidemic of Thyroid Disease and Can We Prevent It?” Animal Endocrine Clinic, 2012.
12. Becker, Karen. “The One Feline Feeding Mistake That Can Lead to TWO Top Medical Conditions,” Mercola, 2013.
13. Becker, Karen. “Implant Radioactive Substance, Abandon for 7 Days – Could You Do This to Your Pet?” Mercola, 2016.
14. “Thyroid Disorders in Cats and Dogs,” Only Natural Pet.
15. Diaz, Guillermo. “Feline Hyperthyroidism: What You Need to Know,” Feline Nutrition Foundation, 2012.
16. Peterson, Mark. “Nutiritonal Management of Feline Hyperthyroidism: What’s the Best Diet to Feed these Cats?” Animal Endocrine Clinic, 2011.