Why are my female dog's back nipples hanging so low and dark purple?
I have an almost 2 yr old female bullmastiff. We've noticed lately (couple of weeks) that her back nipples are hanging very low and are dark purple. We thought that she may be coming in heat, so we brought our male to her, but he was not interested. We are going to the vet first thing Monday, but wanted an idea now of what might be causing this.