I found it a few minutes before it got dark and did not have time to do a proper cleaning. Thinking it was a piece of glass or sharp stone, I tried to pull it off with tweezers, but it was hard to get a hold of, and would not come off. Tomorrow I will do a proper cleaning and examination.
After a long soaking and alot of scraping it came off. Its not bumbblefoot! I was very relieved that I did not have to do an operation. He is still walking weird, but I am beginning to suspect that might be because his spurs. The way he walks really isn't a limp, now that I look at it. He moves one leg out to the side then swings it up high before putting it down.