Hi, I'm Dr. Deb, I'm not really sure what this is. I just wanted to mention that I once saw a dog with a sort of similar problem. He had a fishing line wrapped around his leg. It was very hard to find because it had gone through the skin and hair. It needed to be clipped and surgically explored to find it- while he was under anesthesia. This may not be the case but I wanted to mention it. Were you anywhere near a fishing area? Ice fishing is very popular in some regions. I hope the answer is found soon, it sounds like he is in good hands. Best of luck.