I have 3 australorps. One has had mud butt for a month or more, so I offered grit and oyster shell, but it didn't fix the problem. Today she's looking unwell - tail drooping, mouth open, head to the sky and making small chirping sounds (she's normally the loud one). I can't see any other symptoms. I believe she's still laying, although probably not every day. Any suggestions on what to do? Thanks!