Aw, when I saw this post it just broke my heart. I've had 4 ratties at different times (lived 4, 2.5, 3, and 3 years). My third rat Sammy had 3 strokes near the end of his life and would become paralyzed for awhile. All summer long, I gave him tylenol with strawberry milk and did rattie physical therapy. I figure that all medication was probably tested on rats before it ever got to humans anyway, and aspirin does come from birch bark, a natural substance. By the end of the summer, he was able to walk a little bit, but he died after the last stroke, which he suffered while I was holding him. My parents got me a cute baby rat a few months after. I never considered Smokey to be a replacement rat of any sort. He was a different rat with a different personality. You never forget an old companion, and even if you have a new one, that doesn't change the relationships or fond memories that you obtained in the past.