What should I do for my dog's nail?

My dog was adopted. He has had a broken leg that never healed right that he still deals with. His leg doesnt really bend, so it drags a little bit on the ground. Just a bit ago, we found a bit of blood on his toenail. It looks like it has been ground down to the vein and is now bleeding. We keep cleaning it insanely every so often (becuase he licks it). We've tried to make several makeshift bandages but he will not keep them on. Any advice as to how to heal this up?