I have a sick skinny pig, and I need help identifying a "diagnosis" or source of her illness before it is too late. The vet won't see her for atleast a week, so I need help identifying the issue now so I can keep her stable until then. She is a black hairless guinea pig, about 3 years old, her symptoms are- weightloss desperation for food even though she always has food available, a couple of round circular sores on her back, and then her random splotches of skin have gotten lighter-like a light brown, so she currently has like a cow pattern even tho she is normally just black. this hasn't been going long, she is still eating well and has good energy overall. I've been a guinea pig owner for a long time and am extremely perplexed by this. and suggestions are appreciated