My DC's are scared of dogs entirely because of thick owners* with their unruly "friendly" dogs. When a child is screaming/ crying at an enthusiastic hound on face level, it's not OK, call the dog off and put it on its lead. 
The younger one is fine with dogs on leads, and slowly ambling dogs, but a bad encounter takes time to get over as we don't know any dogs to familarise with. The older one seems permanently weary now 
I like dogs. I grew up with big ones, kept on leads because we could not risk them jumping around at other people and bowling them over. I'm not even cross with the genuinely appolgetic owners who act immediately. I accept there dogs who are well used to children and come happily wagging their way over, just take responsibility for the dog if they are causing distress.
Then again I'm riled and ripe for a rant because I've had yet another encounter this morning with the dipshit owner whose dog is "friendly, but just jumpy." Yes, I know your dog is jumpy, I told you months ago to put it on its lead after it jumped up at me for a THIRD time in minutes, and apparently I was scaring it because I said "get down" sternly
It seems a nice dog other than its crap owner with no boundaries!
*specifically thick owners, not all owners.