Are you able to get him into a vet? If so, the vet would most likely clean the wound and then prescribe Baytril as an antibiotic and then metacam for the pain. If you can't get him into the vet, then isolate him and clean the wound. You can use use iodine or just plain saline or water. If it is a cat bite, that can carry bacteria. i'm sorry i don't know what you should use other than what my vet might prescribe. Perhaps someone else can help with this.
If you don't have anything to stop the bleeding, corn starch will do the trick, or sometimes just simple pressure on the wound for approximately 1-2 minutes will stimulate the body's natural healing process. My vet explained it all to me one time, but i forget the specifics. But there is something about the pressure that brings the body's natural defenses into play to stop the bleeding.
How is he doing now?