I noticed my fawn and white indian runner has been slow and a little gimpy, she also stands favoring one foot. I picked her up and examined her feet and there are these big black calluses on her joints and on the base of her extra toe the callus has grown sideways and seems to be spur-like and is also blackish. They don't appear to be bleeding, but they look like they could go that route if they get bigger and dry out more. This problem has been observable for about a week and a half. She is 25 weeks old. I have pea gravel in the yard and hay/wood shavings under and inside their coop. I wet down the pea gravel/sand on hot days so the heat factor can't be that bad-especially since the other ducks don't have this problem. I have 5 ducks and a goose and the fawn/white runner is the only one with the foot problem. I am concerned it will affect her ability to get extra tidbits and food since she is so slow now, and I don't want her in pain. I read in Holderread's book that it could be vitamin deficiency or rough ground. They all eat the same thing (2/3 layer pellets, 1/3 scratch) and walk on the same ground. Has anybody had similar issues with their ducks?