I went to play with my rat today and noticed that he was rolling his behind over to one side instead of laying flat like he normally does. I looked and his hind leg is completely swollen and the toes of his paw are curved. It was normal yesterday and I don't have him in a cage with a wire bottom so I don't know what it could be.
Could he have climbed up the side of the cage and got his back foot caught? and tried to drop down and hurt it? how old is your rattie? I had a thing called Hind Leg Degeneration on one of my male rats when i was a bit younger it started with a limp in one leg, it got given an anti-imflamatory/pain killer but he still eventually lost use in both legs, i would talk to your vet and ask about glucosamine! a substance used to help dogs an cats with joint problems, i've heard smaller amounts can be used for rats, but iwould definatley check first!!