The likeliest possibility here is mammary gland hyperplasia as a result of the adrenal disease. The increased estrogen can do it - it's certainly not common, but I have seen in about five times over the years. Please get a photo if you can, and if a biopsy is ever taken, I'd be happy to read it at no charge. I am unfamiliar with any side effects of the medications that you mention that would cause this. With kindest regards, Bruce Williams, dVM [Posted in FML issue 3623]