female quinea pig going bald and mounting

Question
hello. I have 2 female guinea pigs. I have had them about 8 months now and they are good with one another. But the past week or so, one has been almost like "dominating" the other one, like almost wanting to mate with her. And the one doing the "dominating", is losing fur, kinda like shedding. it started as a small bald spot and now it seems to be growing larger. what should i do? is this spot coming from the other female or does she have something wrong? thanks for your help.

Answer
Bold spots can be due to many things, barbering where the GP eats its own fur or the other GP is eating its fur, Hormone imbalance, or mites.

I suggest getting you GP to the vet for a skin scraping to check for mites and a blood test for hormone imbalance

It is natural for GP's to show their dominance in a female group by mounting each other. Oh and check the sex of your GP is not male too. There have been incidents where even breeders (non pet shop sellers)mistake the different sexes