I pretty much share Big Cholla's concern over using an ASP for defense against humans. However, I have considered it for dogs. In my limited experience, at least some dogs react to Man With Stick by retreating, thus obviating the need for a strike at all. If you do need to use it, and it works, you'll be glad you didn't have to fire a pistol, which is quite a bit louder and more or less appropriately alarming to the neighbors.
For bicycling, I find that a section of fishing rod Velcroed to the top tube is the easiest way to carry silent anti-dog weapons. Probably a lot safer to use than a pistol, too, not that I wouldn't have one of those, too. I have carried the rod when walking in an area with known unruly dogs. For general use against dogs, an aluminum ASP is certainly a lot easier to carry.
Strangely, a baton is legal to carry in MA until you get into a ruckus with one.