I know some people who feed oxtail. I think it can be fatty though so you have to be careful. You don't want to feed a lot of fatty things to your dog. I always peel the skin off of the chicken backs I feed my dogs.

Here is a site with a lot of info and helpful tips. I have a few others, but I'm not at home right now, so I don't have access to my bookmarked sites.

Raw Dog Ranch