[spiritwings1202]

How old is he?
Did he just start doing this?
Pixie went through a biting stage but never left a mark and all I would have to do is yipe like it really hurt and she would stop dead in her tracks.

You could talk to the vet and ask him what you should do,If it is only when you are putting a leash on then that is a different story he is just trying to get his own way and he has learned that bearing down on you works.

If it is the leash thing I would try a different approach. Like show him a treat and let him sniff out the leash and give him a treat and put on the leash or harness and then a treat again.

Pixie has learned that when we get the harness out it is time to go and she is all about it. I use to give her a treat put on the harness and then treat again and praise praise. Good luck