Is it bleeding? If so, either apply a damp styptic pencil to it to get it to stop bleeding, or bandage a tiny bit of flour in place to facilitate clotting. If you can't get it to stop bleeding, you will need to get him to the vet. If it is just a matter of a ragged nail, you can trim it off; just get someone to help you hold him so that you don't do any more damage.
my sisters dog did the same your dog will keep it clean by licking it you can get a warm wash cloth and wrap it around his paw as long as he lays down next to you to keep pressure on it! I've also HEARD Of putting flour on it to clot the blood and go to your vet.
Oh geez people act like this is a life or death situation...if its not extreme, its fine! My 4 month old puppy did the same thing and my vet said time will heal it..2 days later, she forgot all about it! Hope the best of luck to your dog:)
Don't let your dog lick it. Their mouths are full of germs. Soak it in warm sudsy water then wrap a clean clothe around his paw and put a dog boodie on it for a day or so. Watch for pain, swelling or pus. If this happens go to the vet. Your dog will be fine.