More feline health information from the NAVC. I attended an interesting talk on feline hyperthyroidism. This is a fairly common disease in geriatric cats. In fact, it's the most common endocrine disorder in domestic cats. Endocrine disorders are glandular problems and this one obviously affects the thyroid gland.
One interesting tidbit I learned at the session is that this disease seems to be getting more and more common in older cats. Researchers don't know why, but hyperthyroidism is increasing faster than two other common older cat problems; chronic renal failure and diabetes.
One theory is that cats are living longer and getting better preventive care. As a result of more and better care we pick up more hyperthyroidism on physical exams and routine screenings. This is important because the typical presentation has changed over the years.
It used to be pretty easy to spot a hyperthyroid cat. Many were skin and bones by the time they showed
up at the vet clinic. These days, due to the high prevalence of obesity; 40% by some estimates, the weight loss associated with hyperthyroidism goes unnoticed. In fact, a common scenario these days if that hyperthyroidism is diagnosed subsequent to weight loss therapy.
It goes like this. A cat is on a weight loss program, successfully loses weight, changes back to a maintenance diet but continues to lose weight. That gets the owners attention and they take them in for an exam where hyperthyroidism is diagnosed.
Other studies have looked at dietary and environmental causes of hyperthyroidism. Several studies have shown a link to feeding canned food and hyperthyroidism. This obviously caught my attention. As a former Purina person that would be cause for alarm. Besides the obvious there are other concerns. Most veterinarians recommend wet food for
urinary tract health. Wet food gets more water into the cat's system and helps keep them healthy.
I asked the lecturer about this after the talk. Did she counsel owners of older cats to avoid wet food? The answer was no. She's not convinced the link has been proven. The higher incidence of hyperthyroid cats on wet food may simply be because more and more cats are getting a wet food recommendation for other health reasons. Wet food is more palatable and older cats tend to be a little finicky. Owners gravitate naturally to more tasty wet food as their cats age. The lecturer feeds her cat wet food, too, mainly for the urinary tract health benefits.
The bottom line is that we don't have a definitive answer about the causes of hyperthyroidism in cats. More investigation is needed and this researcher thought we might have a better answer in the next few years.