guinea pig with sore leg

Question
Hi, my 1 year old guinea called Abi has recently begun to have difficulty in moving her back legs.  Rather than walking she is hopping very slowly, often preferring to remain in one place. When she is resting she lies on one side with one foot off the ground, which appears to twitch now and again. The vet has prescribed an anti inflammatory and pain relief, but feels that little can be done if she doesn't respond.  She is eating plenty of fresh food but very little of the dried pellets or hay anymore.
Do you have any ideas as to what could be causing the problem - as the vet couldn't seem to shed any light on it at all.

She is a very sweet piggie and we don't want to see her in any pain.

Many thanks,

Answer
bumblefoot is the most common illness, and if the vet perscried snti inflamitories then he is probably thinking it might be that too. there are a few things that are likly to cause her condition which would have similar treaments, her floor moust be soft and dry. i would recommend a fleece covering her floor for the time being.

Also is it the foot that appears sore or the leg that seems swollen, if so it is a world of difference, i am going to assume its the foot.

finally if the leg cannot be healed then all is not lost, there are pleny of guinea pigs who make do fine with only three legs