Not an emergency. Roosters spurs bleeding

[Emma_Bruffy]

So my big boy Oscar started officially growing out his spurs a few months ago. They are a decent size now and I saw blood trickling down his leg, I assumed that he might of cut a hen but upon further inspection it was his own blood. We guessed he caught it on something and sprayed Blu-Kote on it. Well today it happened again, I saw it before the blood trickled but what is this

 

[nuthatched]

Could he be catching them on something?