My dog some how cut the end of his tail. He didn't cry or anything. It was bleeding quite a bit. We clean it and it seem to stop bleeding. As soon as he started wagging it again, it started to bleed again. This morning it wasn't, but when he became happy and hit the tail on the wall it began to bleed and again we were able to stop the bleeding. Should we take him to the vet or give it a few days to see if it will heal?