I tried the brewers yeast with garlic on my dogs because I don't like putting chemicals on my dogs. They soon had the worst case of fleas I have ever seen. I had to treat the yard, the carpet and the dogs to get rid of them. I then started giving them fresh garlic. It has been six months now and not a flea in sight and no reaction to the garlic. Garlic is far better than chemicals in the topical flea treatments like Frontline and Advantix. ... View related article.