My boy Finnian came off the track with about 8" missing from tail. It was well healed, and no problems with it for 5 years. Then, he whacked it good on a door frame, broke open the blood vessel, and things went downhill fast. Got the bleeding under control, but he broke it open again within a week, ended up at the e-vet getting the blood vessel catherized. Was so afraid he was going to bleed to death. Just couldn't get it stopped. Then, he was fine for another week... broke open again and ended up having the amputation done. Now he's got a cute little stub that's in very good shape.