Hello I have a problem about my chihuahua. My chihuahua has always kinda hopped because my mother accidentally steped on her back foot. But don't think its the same leg. But recently she has been kind of swinging back right leg in a circular motion when we go on walks. She is 4 yrs old and has been healthy and active ever since she was 6 weeks old. What do you think this could be? And what should I do?