Yes, this is bumblefoot. There isn't a whole lot you can do for this condition except let it heal on itself. However, if it is an open wound, oozing and bleeding, you need to get him out of the pond and on a soft surface like the rubber mat. You don't want to give him a slick surface as he can sprain, strain or break his legs. Use neosporin and place it on the wound. This will allow an open wound to heal, but basically, bumblefoot is a condition similar to a callous which keeps forming over an open wound with infection due to hard surfaces.

The sore gets extremely large and waterfowl have a hard time walking on the overgrown "ball" on the foot. The sooner that the foot can be healed and concrete or other hard surfaces removed, the sooner the bird can be returned to the water. Having said this, usually, you can treat the wound until it closes, but the condition will remain. If in doubt, get him to an avian veterinarian with expertise in waterfowl. We hope this information is of benefit. The Regal Swan