I raise mice for work (don't ask). And at work we have several mouse colonies. I've only seen open sores on overcrowded colonies or those with too many males. You may not see them fighting but the males will attack and bite the weaker ones, even going so far as to chew off their testicles. Gross but true. Most bite wounds are found on the rump. Is that where his are? Try separating him out to his own cage or if you have a couple of girls, let him have those for company. I only keep 1 male per cage and have never had a problem with this. You're right - if it was parasites like mites, more than the one mouse would be affected.
I have a pet mouse he is the only one in the cage. He has open sores on his back. I clean the cage regularly. He has a very healthly diet. I think the sores are from his scratching with such sharp nails. He has chew and scratch sticks but his nails remain sharp. Either way, he constantly scratches and I really feel bad for him. What can I do? Could this be a form of allergy? Mite?
Definitely could be an allergy. Skin parasites tend to cause the fur to thin out and the mouse goes rather bald. I see this most often in squirrels with mange. What type of bedding are you using? I avoid the cedar shavings. They smell nice but those strong aromatic oils can be irritating to small animals.
Mostly I worry about his open wounds. They're just an invitation to bacteria and infection. I don't know how bad they are but if they're more than a little roughed up and pink, if he has an open, wet wound, then he should be seen by a vet. I don't want to recommend any home care. It's a trade off I know cost-wise. But it's a shame if he's suffering.
Try a different bedding too just to see if it helps. Even if you're using pine or corn cob bits, see if there's another type that might help.
I need help fast! My pet mouse(girl) has a huge lump on her side and it have a big sore on it that is bleeding! She isn't moving around and she seems to be having trouble breathing. I don't know how she got the wound. She lives with one other female mouse and is very energetic. How do I help her??
My little mouse has a little open wound right below her ear. She lives with one other female mouse, and they get along, always running on their excersize wheel together, eating together, like they are best friends. I just noticed this today, and she wont stop rubbing her ear. She has a very healthy diet, drinks plenty of water, and I change their cage regularly. She keeps scratching her ear, and when I took a look at it, and slightly touched the pins of her ear wearing a latex glove, she flinched, as if she was in pain, so I didnt touch the outside of her ear again. Shes acting completely normal, however, I believe there might be something wrong here. Can someone please help me?