The City of Plattsburgh does have a dog leash law. And there is no reason why other dog walkers should have make detours and run away from your dog. Leash it. And your suggestion for carrying a whistle is absurd. BTW, pick up your dog’s mess.
I want to remind people that dogs are welcome everywhere. They are family members too. Just because you see a dog does not mean they are going to bite you. And if you are allergic, don’t go near the dog or cat.