I've never canoed with a dog, but I have a friend who does it all the time. Takes his husky cross and his German Shepherd. He's never had any problems with them. They both know "stay" and are pretty consistent with it. I think the rocking of the boat keeps them still too.

You can buy kayaks with a spot for a pet or small child. I looked at a few of them before I bought mine. The salesman recommended that if I wanted to take a dog I should get a sit-on-top model. I don't like those though and kayaking is something I do without the dogs anyway. It's my down time where I don't have to worry about where they are or what they are in to! I'm hoping to try out the new kayak this weekend!