"I have a couple questions for those who feel they want or need pepper spray to defend against humans. Do you carry it at home too? If not why do you feel the need on tour? Are the areas you tour less safe than where you live?"

Where I live, dogs and bears aren't a problem. Anywhere outside of the city they can be though I haven't been attacked in my home province, by an large.

I think one issue about spray is that if you are carrying it for whatever reason, you need to have a human policy on the stuff. It will be to hand, so it might get turned against you during a mugging , or vice versa. So does that make one want it to be low power, high power etc... Better to think it through.

Pepper spray is different in the different concentrations. Tear gas, for instance, has been widely replaced by spray because the TG "only" causes the pain, nausea, etc... A person can fight through it. Pepper spray is preffered because it also affects respiration, and is more likely to "shut an attacker down". This also means it can be lethal since a person with a problem in respiration could end up seriously affected. You have your light sprays, your real sprays, and your real sprays for animal way stronger than we are. It is worth understanding what you are doing if you spray an attacker. If you were attacked in a way that led you to believe you were in risk of imminent death or bodily harm you can use lethal force. It's just worth understanding that pepper spray is a different kind of thing and does not operate merely by causing pain, which is both the good and bad news.

"In all honesty, I'm more concerned about the dogs than the people. I don't want to hurt a dog more than in necessary to get it off my heels, as I see chasing bikers as something instinctual to them. Maybe I'm too soft-hearted, but I don't want to hurt an animal for doing something that it doesn't do with bad intent."

It's not the chasing I mind, it's the bitting or entangling. I think you a muddying the waters on instinct. We had a pair of mastiff's in our region that tackled and half ate a girl's leg off, along with other serious wounds. Not a cycling accident of course. Shoot first, ask questions later, if you want to. Dogs seem to have a blended personality where they won't touch cars on roads where they chase me, can be held back by their owner's voices, or when left alone will/would drag down deer and cyclist's with impunity. So they obey some laws they have been taught or have learned to respect, can be controlled by their owners directly, but there is another area where they are doing their own legal. It really isn't that different from a serial killer. Those guys have learned what they can and can't do, who they have to be careful around, and then there is that area of their life where they can be playful. Call that area instinct if you like. But it's the area where your humanity (in whatever sense) is indistinguishable to them, from that of a jelly donut. If that makes you feel charity, god help you.

"I personally don't think you need pepper spray to deter dogs anywhere in the continental US."

I've found places in well settled areas in Canada. What I find is the kind of lots where people build on an acre or two in the country, get a BIG dog, leave all day for work, maybe get the dog a companion, leave them outside to do whatever they want. To make maters worse, these homes are every few hundred yards, at times it reminds me of scenes from Black Hawk Down. There is no let-up, and getting off the bike is no salvation unless you want to walk the whole way.