Reply #8: perhaps something further needs to be said about pet "biological" diets....

[mike_c]

It's not true that raw diets precisely mimic the "natural diets" eaten by wild carnivores. Setting aside the issue of composition for a moment, what often escapes notice is that while prey are indeed raw, they were closed packages with functioning immune systems up until the time they were killed. Raw meat from previously slaughtered animals is a bacterial growth medium, and as you point out, the industrial scale of the meat packing industry precludes any serious attempt at sterility.

Also, carnivores can and do acquire both pathogens and parasites from their raw prey. That too is "natural" and "biological" but it's not something I want to happen to my cats.