I'm pretty sure my dog is allergic to brewer's yeast. I used to have trouble with her eating her own poo, so I bought the Potty Mouth tablets, which are made mostly of brewer's yeast and gave one to her. I noticed she had kind of some little red spots on her snout so I never gave her another one of those again. I've read that it is common for dog's to be allergic to it. For whatever reason she doesn't seem to be interested in eating her poo lately, so I'm glad. I've always fed her really nutritious food, so I never could figure out what the cause of her poo eating was in the first place.
