My Sophie was big at bunny hopping when she was smaller. Now she is a bit bigger (3.5lbs) and 8 mos old she doesn't do it as much. However, She has been hiking up her left rear, acts lame and sometimes just keeps it slightly off the floor. Our regular vet said her knees are fine, but I don't think so, but I sure wish he was. I had heard that the bunny hopping was something that those with LP did alot.
I am very afraid she does have LP.