True! Clean up after your dog, don't let it bark incessantly at people and even if your dog is very people friendly, not all people are happy to have a dog run up to them (especially if it is a big dog).
I've never had any problems with any dogs I've met on the canoe trail, of course, I love all dogs.
Not to commercialize, but just to let you know I am one of those "outfitter types"
1829 East Sheridan Street
Ely, Minnesota 55731