My mouse seems to be...?

Question

My mice's tail is bleeding, it's like the tip of it has been bitten off and there's something on her side, like she's loosing fur there, but maybe there's a lump. Won't let me get close enough to see. She's in a cage with her sister, plenty of fresh water, with vitamin drops, and eats the recommended mouse diet... what could be wrong with her?

Answer 1

Separate them immediately! Watch her closely and if her condition gets worse take her to the vet. I'm not sure how much they can do, but they might be able to do something. I hope she comes out ok!

Answer 2

Nothing maybe they been horse playing around

and having fun. Just like a blister for humans

it'll eventually go away. if not call the vet!

but im sure nothing to be worrying about