Was feeding the dogs basic dry food with occasional wet dog food. They were always scratching with or without fleas. Tried the expensive supplement advertised on the radio. Made one of dogs sick as, no I'm not gonna say it. Switched to the Beneful Healthy Radiance. and after about 6 weeks the dogs do look much better and have stopped the constant scratching. Much more expensive than basic dry food but not as much as the expensive supplement was.