I've used Mace before and in my opinion, it's just too brutal. There was a German Shepard that gave cyclists trouble on a popular cycling route when I was in college. I mentioned this to my father in law (at the time) and he "loaned" me his Mace (not sure how he got it).

So a few days later I was out on the above noted route, Mace in jersey pocket, when the German Shepard came after me. I waited until he was about 8" away from my right chainstay, then let the dog have it with a (very short) squirt of Mace; pretty much a direct hit to the face.

The effect was immediate. The dogs front legs folded under and the head hit the pavement, pretty much face first. The dog rolled over into the ditch and just stayed there, not sure how long. So yes, far too brutal. But . . . to the best of my knowledge that dog never chased a cyclist again.

Rick / OCRR