I have been treating a duck ith a foot sore for several days and I still am not sure what it is. There was a black scab topping a large swelling on top of her foot. She limped and hopped badly. So, several people on here said to treat it as bumblefoot. I applied triple antibiotic cream several times a day for several days now. The scab loosened and came off but did not reveal an open pus-filled or "cheesy" center. So, today I decided to explore it a bit and when I poked it with a scalpel it just bled a bit. It acts and feels like it is fluid filled like a blister. Should I keep digging at it? The curious thing is it is on top of her foot.