Last summer I purchased a registered Nubian doe with a set of twins, and about 5 weeks after I started milking her I noticed some swollen spots on her 1 teat and right where the teat attached to the udder. She would not let me milk her and we had to hold her legs to milk her out. The spots would harden and then get scabs on them. My vet was not even sure what they were, but thought that they were a virus of some kind. I treated it with penicillin and it seemed to help. I also, saw this same thing on 2 of my other does that I have been milking for a couple years, and had not had any problem with these sores.
Do any of you know what these sores are and how to prevent them?
Is it safe to use penicillin while the does are nursing?