Hair loss

Question
Hi, i have 3 male mice two are brothers and one is the son on the dominate mouse. my two oldest mice are probably 3 or so. Lately my mice have been fighting so i separated the two brothers and son. the brothers share a tank. my dominate mouse had started loosing hair but he was not the one being picked on. today when i  checked  him he had another patch of fur missing. is this a medical thing or is he just getting old? should i separate him from my other mouse just to be safe?

Answer
Dear Emily,
thank you for your question.
Old mice often get thin fur, but not bald patches. It's more likely that  he has a fungal infection or some other health problem. I recommend seeing a vet with him. www.rnca.org/Vets has a list of good mouse vets.
Leave him with the other mouse, being separated will be very stressful for him. The other mouse may need to be treated too, especially if it's a fungus. Apart from that, you won't be able to introduce them again if you separate them now.
I hope I was of some help to you
Jennifer