Some dogs tolerate it, others don't. What is being used now? You might try Advantix, though I hear Comfortis works very quickly.
We had the same problem for awhile. He was itching all the time, but I never found fleas on him. I tried Frontline and that didn't work. I read around, and asked a few people, and some recommended Comfortis. I used it with my puppy, and he is just fine now. Only thing I can say is to feed him, and then once he is finished, then give the pill to him. The pill alone can cause the dog to throw-up if he is on an empty stomach.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.