I was messing with his feet today and noticed a node in his 'feathers'. It was hard and circular, attached to the leg. It felt rather like very hard skin, didn't seem to bother him one bit. I found it on both front legs, but I didn't check the backs. I would guess one was about a quarter inch in length, the other just a smidge longer.
Any ideas as to what this is? Never seem anything like it on my less-hairy horses.