I noticed about two days ago that my chihauhau mix had a lump on her tummy, near the base of her right leg. It is probably about the size of the end of my thumb and seems to have grown a little. This morning I noticed a thick, black scab had formed over it. She licks it almost constantly, and it is sensitive to the touch. She just finished tearing off and eating (ew) the scab, and now there is just pink flesh exposed. There doesn't appear to be any fluid in it though. I though for now I should clean it , put neosporn on it, and try to get a bandaid to stay on. Any suggestions to what this could be? Does she need a visit to the vet? It is starting to worry me. Thanks.