has anyone used comfortis pills for fleas? do you feel it's safe? my dog has been scratching a lot and his belly is getting red and irritated. i called the vet and he is prescribing comfortis. was just wondering if you have had success with this being used on your dogs. i don't see any fleas but vet seems to think this will work. i hate meds for him, but, i want tosee him feel better. please let me know what you think. thanks.