You can't get him AKC papers, but you can get him what is called an ILP number (Indefinite Listing Privelege). Which will allow you to compete in AKC events, I believe, almost all except for conformation. If you go to the AKC website (
www.akc.org) you can look up ILP and get more information.
I got an ILP # for my rescue boy last summer - now, I just hafta actually get out an start competing in obediecne events to get his CD title!
If he didn't come AKC papered, you can't get AKC papers for him, unless you know the pedigree (or at least the parents) of the dog.