Last Tuesday we purchased two cavies from Petsmart (Yes, I know...we didn't know about adopting). We added on to our store bought cage and have been having trouble with one of our piggies using the ramp. I say this because I'm not worried he fell off a ramp or anything. However, this evening he is turning his head to one side and it is staying there...and he once fell over and had some trouble getting back up. He seems fine...he is eating and drinking. Any suggestions on what could be causing this or is there some type of disease in cavies to be aware of??? We bought several books and I can't find anything in them. Any help would be greatly appreciated. We are very worried.