Slogging up a hill I was passed by a young woman jogging on the sidewalk with a smallish dog. It looked like a border collie mix. The dog was pulling on the leash from behind and had a slight limp. After cresting the hill I was able to catch up with her. I pulled in front of her and admonished her to slow down because her dog was struggling to keep up.

"He's fine" was her petulant reply.

What could I do? Just hope that when she got home a more compassionate family member would notice the dog's distress and speak out.

I do not object to people jogging, even biking, with dogs, as long as the dog is liking it. Some dogs are runners and the only way to keep up is on a bike (though this is difficult and requires training).