Yes, that could be the source of problems. About the arthritis, one more thing. Heidi Ann came to live with us four years ago from a local non kill shelter. She is a fiesty little girl and always had a funny walk- I used to call her "my determined little" girl. It turns out it was all arthritis, not a funny walk at all. She was diagnosed early this year and she has it in all her joints. Her weight is not helping either, but she is on a measured diet food quantity and that is the best we can do. I feel really bad that I did not think about her joints earlier to help her out. Now she can not jump on beds, goes up and down the steps with difficulty, and we can hear her joints crack. But she is a little fighter. So, maybe looking at his joints won't be a bad idea. Good luck with Paddy baby, you are a very loving mom!