How long should you run with your dog (about)?

I have a JRT mix who is 25 lbs she loves running with me. She shows no distress during or after our run but I want to make sure in like 5 years she doesn't have joint pain or something because I ran her. How long about should you run with your dog? I was thinking only 30 minutes of steadily running wtih me? (she's used to exercise) Thank you.