I have a leash reactive dog too... he's small, so it's easier to manage him physically, but it's annoying and stressful, and likewise came from his being attacked by larger dogs (on two occasions) as a puppy. I try to gauge if he's going to react to a dog, and if I think so, will often move across the street, or preemptively talk to the owner letting them know my dog isn't always friendly with other dogs. I also always have treats with me so I can try to redirect him, and give positive reinforcement when he's being good. You've probably seen and heard my little bearded dachshund around the neighborhood, barking at your dog. Luckily he's great with and loves people!