Albino mice

[Bogertophis]

I agree, & unless you want to spend a lot of money at the vet to help her, euthanasia may be kinder than letting it go on. May also be something contagious to the
other mice in the same cage. Was she an adult mouse when you bought her? Sometimes even female mice fight (blood in ear?), which causes stress & that means
lowered immunity to other issues, contagious or otherwise. Not sure the vet can fix this anyway -they don't often work on rodent pets because owners don't want to
spend the money on something so (forgive me) "replaceable". At best, mice don't generally live longer than 2 years, so if she was an adult when bought, she might
have been a year already, & like anything else, lifespan varies by genes, luck, good care & not being exposed to diseases & parasites. She is obviously sick (weight
loss, not grooming, panting) but I can't tell you exactly what ails her, nor whether or not any treatment will help, but she shouldn't be kept with the others. Like us &
other animals, mice can get cancer & all sorts of ailments, & the odds go up the older they are.