Leg wound

[Huckleberry]

Just went out to take care of the goats and noticed my 9 month old saanen had a huge wound in his armpit/front of leg. I was scared to look closer as it was pretty big and I thought for sure we would have an emergency trip to the vet. Ended up not needing stitches, looks like he scraped it on something pretty big. It shaved off a patch of flesh and hair about 1.5 inches wide and 3 inches long. Had little folds of skin on the bottom like it was pulled down maybe. Almost looked as if something flat scraped it down. He was fine yesterday afternoon so it happened sometime between then and now. It has started to harden over and he was running and jumping like nothing was wrong. Treated it with wound cream as it looked pretty clean. We looked all over for the cause as there would be a pretty big piece of flesh and hair laying somewhere, but came up empty. Doesn't appear an animal did it since it looked like a flat surface (kinda leveled out the curve of the skin). Still worried until I find the cause though.