Hyperthyroidism in Cats: The New Scourge

Hyperthyroidism, or excessive production of thyroid hormones, is fast becoming a common and intractable disease of older cats. Once a cat is struck by this disease, it becomes quite ill and needs constant and expensive treatment. Why has this disease become so widespread?

When I was studying veterinary science in the late 1970s, hyperthyroidism was not considered very significant. Even while working for veterinarians in the early 1980s, I don't recall seeing many cases or hearing about it very often. Nowadays, it seems that not only do I read about it on a regular basis, but I know people whose older cats have been diagnosed with this disease. What happened between the late 1970s, and today?

Thyroid disease, whether hyper- or hypothyroidism, is considered to have its roots in the immune system. Either the immune system is over-stimulated, causing it to attack the body itself, or it is suppressed, allowing pathogens and mutated cells that would normally be disposed of to thrive and cause disease. According to veterinarian-authors such as Donald R. Strombeck and Richard H. Pitcairn, hyperthyroidism is a disease that was seldom seen in cats until well into the 1970s. Strombeck notes a direct correlation between the feeding of canned cat food and the emergence of this disease, as does Pitcairn, though they state that the reasons are unclear. Pitcairn also indicts the practice of administering multiple vaccines at once, a method that evolved over the years and was not common 20 or 30 years ago.

Another well-known author of holistic pet-care books, Anitra Frazier, mentions the fact that commercial cat foods are processed at very high heat. To replace nutrients lost during this process, additives and chemicals are introduced, and these can cause allergic reactions in cats. Allergies, an over-reaction by the immune system to some irritant, can, over time, cause the immune system to go into overdrive. In humans, this often presents as "multiple chemical sensitivity syndrome". In cats, it is probably something similar. A bombardment of an animal's immune system by multiple vaccinations can have the same effect. Conversely, the opposite can occur, whereby an overtaxed and stressed immune system just "gives up", resulting in diminished immune function.

Next week, I'll talk about the prevention, symptoms and treatment of this disease. Stay tuned!
Chat later!