I Think My Gerbil Is Sick

Question
I just bought a female gerbil from the pet store exactly one week ago. She was a little scared but in a few days she was really active (exploring the cage and playpen, running around, etc.). But Yesterday when i got got home in the afternoon, she wasn't herself. She was walking slower than normal. Also, her but is big, or swollen. Every now and then it leaks a brown fluid like diarrhea but it isn't a lot. Last night she slept in her food bowl. Now she is in the toilet roll i gave her. She's usually active. Can you PLEASE HELP me. I'm scared she might be dying. Is it probably the food i gave her? It is a food mixture. I occasionally give her pieces of fruit (mandarin oranges and grapes), bread, and cashews.  

Answer
Hello, I wouldn't give your gerbil any citrus fruits r grapes. They can cause upset stomachs and it sounds like your gerbil may have Tyzzer's disease and I would really consider taking your gerbil to a vet. Don't give her anymore fruit until the diarrhea clears. Here is an article on Tyzzer's disease. It's a really serious condition and without a vet's treatment the gerbil usually doesn't make it. Good luck and keep me posted.

http://www.peteducation.com/article.cfm?cls=18&cat=1799&articleid=2846