Lethargic mouse, runny discharge

Question
hello! :) ok so i just switched my mice food because one of them was getting really fat from overeating? i have 2 mice, both are female and they are mother and daughter. my question is the Daughter is got really fat from the food i was feeding her (a mixture for mice and small rodents i got from the pet store) so i switched her food to the since blocks. anywho over the last couple days i noticed that she has been vary lethargic and today i took her out of the cage and she normally likes to scamper around my arms/hands but she just sat there breathing while i petted her. i had her out for about 30min or so, seeing if she was at least pooping the whole time she was out she only pooped twice and they were little and dry. however while she was also out i noticed a yellowish discharge coming from her backside, however i couldnt tell which one it was coming from so i was thinking it was maybe diarrhea? but its not coming out a lot :/ and im really starting to freak out a little bit. there is no way she could be pregnant because she lives with another female and i dont know if mice can go in heat or not cuz none of my other mice have ever had this problem. and im not sure if this matters or not but her brother (that i gave to my bfs mom) has some skin problem it starts with a D i think, i dont remember but so far she hasnt had any signs of what he has. so i really dont know what it could be. any help you can give me would be great i dont have lots of money so taking her to the vet might be out of my reach but i'll see what i can do :/

Answer
Hi Shastina,

She does have to go to the vet. I know how difficult it is to afford a vet visit on a limited budget, so I know this is trouble for you.. But a lethargic mouse one day can be a dead mouse the next day, if it is from a bacterial infection, which it usually is.

The vet might want a sample of the poop if they suspect parasites. When you collect it, put it in a small ziplock snack baggie and press all the air out of it so it will stay moist. Put it in the fridge.

Take her right away. Make sure she stays warm right now. Best of good luck and health to her.

Squeaks

Natasha