Man that sucks. I wish I knew anything about small rodents.
You should have the vet check 'em out. If it's suffering, you have to put it down.

The only way to really know may be to have someone check em.
I couldn't imaging watching my dog die and wondering if he's hurting. I could shoot him if I had to, but I'd gladly pay the vet to do it for me.

I hope that he/she makes a turn for the better