"Walker" does not care for dry dog food so we have been switching brands to keep up his interest. Since we started feeding him IAMS he takes on a really peculiar odour (STENCH). At first we suspected that he had rolled in something funky so he got a Febreeze and baby shampoo bath. Within two days the stink was back and he has not been out of the yard since bathing.

Are there ingredients in dog food that can do this?