My dog loves rawhide bones, but recently when he is eating them, we have noticed blood on the bone. We have taken it away, but would like to know what to do about it so that he is able to enjoy them again.
Definitely have your vet check his teeth and gums. Dogs can get the same kind of dental problems that people do - like bleeding gums from gingivitis. He may just need a thorough cleaning under anesthesia.
On the other hand, I've had dogs that just go a little too crazy with the rawhides and they really irritate their gums with all the chewing. Cutting back to one every other day - or longer - solved the problem.
Bleeding in the mouth can either be a sign of tooth problems (needing a dental cleaning and possibly extractions), gum problems (also needing a dental cleaning and diagnosis), or the rawhide may have cut into his mouth. Call the vet and schedule a dental cleaning - that is the only way to really find out what is going on with him.