Hyperthyroidism is an endocrine disease that affects 50% of cats older than 8 years. In 1980, one in 200 cats were diagnosed with hyperthyroidism. Today, that number is closer to one in 10. Symptoms include weight loss, increased appetite, hyperactivity and a racing heartrate. The disease can be treated with medication, surgery or radiation therapy.
A link between canned cat food and the disease was proposed fifteen years ago. The thought was that zinc in the can leached out into the food and somehow caused the disease. Not much became of that theory.
A doctoral student at OSU proposed and tested a new theory. She found a relationship between a flame retardant commonly used in upholstered furniture, plastics and certain types of air fresheners with increased levels of thyroid hormone.
Her plan is to follow these cats for five years and see if there is a correlation between repeated exposure to these chemicals and rising thyroid levels.