Folks,
 
The USDA mandates that anything that isn't the primary muscle tissue of
an animal be labeled as by-products.  Therefore, by-products can contain
offal, beaks, feathers, etc.  depending on the manufacturer.  However,
just because a product has by-products in it, does not mean that it
contains those things.  By-products can also be organs, cartilage, some
bone, and other non-muscle tissues.  Many of those by-products contain
elements our pets need, and would eat in the wild, such as liver for
iron.  (Have you ever known anyone who took shark cartilage pills?  That
would be considered a by-product.)
 
The best thing to do is
A) look for products that contain chicken {or beef, or turkey} as the
   primary ingredient, and
B) contact the manufacturer to find out what they consider acceptable
   to use as by-products.  That will vary widely from manufacturer to
   manufacturer.
 
The more they hear from us about what is acceptable as ingredients in the
products we buy, the more likely they are to adhere to higher standards.
 
GEC @};~ and the Three Musteteers; Athos {Mischief}, Porthos {Kaos} and
Aramis {Trouble}
[Posted in FML issue 4900]