Here we go again - been hiking the A.T. for 30+ years and never had a bad encounter with a dog, I even took dog treats with me when I didn't own a dog, But don't let me start with with the human pigs I have met.
My best advice is to train your dog - it's very easy, My dog hikes about 5 feet in front of me and when we see a hiker coming I have my dog stop and I ask the hiker if the he/she is ok with dogs, My dog will only approach the hiker if the hiker asks him.
Just came off the trail after 5 days and as usual not a single issue - met about 30 thru hikers and many day hikers.
Lets start a thread on the some of the bad people we have met on the trail.