Dr. John Moffett is an active research neuroscientist in the Washington, DC area, who has published articles on the nervous and immune systems. He wrote on OPEDNews.com:

…… what exactly is causing the recent spate of pet illnesses and deaths? As a scientist I must initially conclude that there is not enough data to come to a firm conclusion. However, that does not mean that we cannot make well educated assumptions. Because melamine is not particularly toxic and is not known to cause kidney failure, it is logical to assume that there are other contaminants in pet food in addition to the melamine.

Obviously, Chinese farmers, chemical producers, and food additive distributors have no compunction against putting harmful or even toxic compounds into products that are to be consumed by either animals or humans. China has a history recently of putting business interests far ahead of human interests. Manufacturers in China have few restrictions on how they operate and whether or not they are permitted to pollute the air and water. Cancer rates have soared in many parts of China that have become industrialized. It has been noted by Western journalists that the smog is so thick in some Chinese cities in that you can stare at the sun without worry because it looks like a dim orange ball in the sky.

Another assumption that we can make based on what is known about toxicology is that it is not uncommon for two mildly toxic compounds to have a cumulative effect that is far more toxic than either compound alone. As such, it seems quite likely that other chemical contaminants originating in China, which have not yet been identified, are also present in Chinese food products. Melamine would almost certainly put a strain on the kidneys because it contains a great deal of nitrogen, and one of the major functions of the kidneys is to clear excess nitrogen from the body in the form of urea (present at high levels in the urine). If Chinese farmers and food product distributors have been putting other toxic compounds into their products for similar, nefarious reasons as they have been using melamine, then it seems quite possible that two or more mildly toxic compounds are having a synergistic effect in causing kidney damage, and eventually failure. [Full Text]