Looks like it has just started....not too far along...and only a few of the ducklings have it. I put some wound cleanser(Neosporin) on it, put some Neosporin on it, and added some antibiotic to the water. I think this started because I had them in VERY close quarters and the pine shaving bedding got damp and packed QUICK and I did have their water on 1/2" welded wire screen. They walk fairly well. It is mainly on the base of the foot and very occasionally it is seen on the 'toes' as seen in the 2nd photo.