[yorkiemini]

I have posed this question to dozens of folks.
Cali at 3 pounds 14 oz does agility and I have been criticized and praised for it, she is in great shape compared to other dogs her age and size and most importantly she loves it. You are correct the A frame and then the walk are considered the most dangerous pieces of equipment. The running and pivoting can be hard on the knees, but frankly, what I'm hearing is that people who practice agility at home on concrete do the most damage. On the courses and the trials it is padded or dirt that cushions.

I had Cali xrayed to check her knees and ankles and such and they were perfect. I feel the exercise is good for her, she is enthusiastic about it and I have enough sense to know when too much is too much.

All in all feel it is better than a dog sitting on the couch all the time, eating too much, and getting winded on a walk. Athletes are generally a fairly healthy group!