Cats suffering hyperthyroidism from chemical in the linings in metal cans of cat food

maynardsclark.spaces.live.com: "Several studies found an increased likelihood of developing thyroid disease in cats who eat a lot of canned food. 

Specifically, they found a higher incidence of hyperthyroidism in cats that ate fish or 'giblet' canned foods. 'Giblet' is another name for organ meats commonly listed on pet food labels as by-products.' Better-quality, natural cat foods do not contain by-products, although some include specific organ meats like liver. Just what it is in these foods that is the culprit is unknown."

Recent research suggests that the culprit may be a chemical (bisphenol A and similar compounds) found in can linings of easy-open "pop-top" cans that can leach  out into the food and cause toxicity (the smaller the can, the more chemical exposure the food has). However, there are at least 25 different types of can linings, and the particular type used by a manufacture may change over time.   It is difficult to know which foods may be affected, and to what degree. The FDA, however, has stated that the amount of  chemicals that may leach into the food is unlikely to cause disease.

A new study that recently captured media attention suggests that fire-retardant chemicals known as PBDEs may be a factor in feline hyperthyroidism. The combination of PBDEs, can liner chemicals, and excess iodine may be too much for many cats to handle.