I’ve never understood leash to leash introductions to strangers. Like, what do you expect is going to happen? My dog is friendly but would wish to play and can’t because they’re both on leashes. It just never makes any sense to me. At best, my friendly dog is frustrated that she’s tethered down she meeting a new dog. At worst, the dogs frustration turns into something else. Some one did this at the vet, in the waiting room, I was like she’s friendly but also has a mystery illness that has so far cost me $600 and we don’t know if it’s contagious but yes please go ahead and allow your sick dog to try and play with my sick dog in an office on leashes. My pup knows “leave it” on leash applies to other dogs we pass on walks. There’s a time and place for introductions and play and this isn’t it.

Nonetheless I’m sorry you had to experience that, I hope your dog fully recovers quickly and sounds like you’ve learned an important lesson.