If you want to teach a child not to be afraid of dogs though - which I agree would be a good thing to do - then you should be allowed to do it on your own terms, in a way you chose, such as taking them to visit friends with dogs, or chatting to dog owners who are happy to do that, or if it's really serious, therapy.
but the teaching shouldn't take the form of non-elective immersion therapy: ie., you will have to put up with some big uninvited dog sniffing/barking/running up at you when you weren't expecting it, weren't ready, and didn't want it to. That's just dog owners deciding for me when I have to get over myself (or that a child has to), and that's not right.
If your child was afraid of water, yes I'd suggest you deal with it in whatever way you think best. I wouldn't come along and throw your child in a river.