Holly is Limping

Holly, our little Boston Terrier, is hurting somewhere. I don't know if she jumped off a chair or the bed wrong but she is walking kind of slow. She is paper trained out in the garage and she is walking down the steps kind of slow this morning and she won't jump up into your lap. She is 9 years old, and almost 10 so I wonder if she has gotten some arthritis in one of the knees she had operated on a couple years ago. They are almost like people in their illnesses. She has thyroid problems, so takes a pill a day for that. It seems if you have a pet long enough, you go through all kinds of things with them, much like yourself or kids.