About 3 weeks ago, I found one of my calves that was about 1-2 weeks old with one of his back legs wounded and the skin around the knee was swollen and full foamy blood about the size of a small basketball. I lanced the leg and the fluid drained but now the stretched out skin has died and torn away, leaving the leg with a 6 inch wound completely around the leg(no skin). We vaccinate all our calves for blackleg but this calf had not been vaccinated yet. I haven't had a chance to talk to the vet or take the calf in. How can the wound ever heal?