I have used Dawn dish soap to help with fleas and it works BUT it needs to be rinsed really good. Then use an oatmeal shampoo for dogs. Often they may have allergies that the vet needs to check for. If you use perfumes that will affect your pets. Especially, room deodorizers will make pets itch. If you use a spray perfume and your pet is in the room it can get on your pet (because of the heavy oil) and work it's way to the skin. Certain flea/tick meds will make them itch also. May also be something in their foods.