Joanne- The vet is concerned Mimi's bump could be a tumor (God forbid) so I guess piggies can get cancer. How old is Macie? I always heard piggies start to lose body mass as they age. Sorry I don't have any other ideas. Hope she will be ok. ~Jaime & Mimi~ ~Missing Molly, Radar, Albert & Daisy~ http://piggiepages001.blogspot.com/