are you sure he is properly de-flead? an obvious point i know, but you didn't mention it in your post. the breeder may have de-flead him to the point of handing him over to you, but your puppy may be due another dousing! you will have to check this with your breeder and vet as puppies and other young animals require quite specific stuff to do the job properly. my cats are scratching too although i do keep this up together all year round as it is very warm now and this year seems to be a bit of a boon to fleas so far anyway...you will have to do something to solve the problem soon or he will start wearing bits of himself away and this will cause further health problems for him (and vet expense for you too!) good luck!