I don't think a dog would have to be necessarily reactive in order to be startled (and react in kind) to having his/her behind suddenly sniffed by a dog he/she didn't know was there. My dog works in packs with other dogs regularly. He's taken courses with multiple dogs. He's in public situations frequently. But he's still going to jump if goosed from behind, especially if it's done by a dog larger than he is, even a dog he knows. I don't think that's a particularly unusual reaction either. If I'm unaware someone is behind me, and that person suddenly says something to me, I'm going to jump too. And really, there's no reason to get your jollies from watching your dog goose someone else's. If you want to know if your dog can greet someone else's dog, ask. Frankly, if you've got your dog on an overly long lead so that he/she can bounce all over my dog (who, in a place like Home Depot, would likely be on his four foot leash, giving him little leeway to keep his distance after the initial greeting, if that was his preference), I'm likely to make up some excuse as to why your dog shouldn't greet mine.
For that matter, in a store where a dog on a thirty foot lead could knock things over or startle other people by nosing them or jumping up on them, a thirty food lead is just a bad choice, and I wouldn't think it was inappropriate for the store or its manager to request that the owner in question keep his retractable lead at a maximum of six feet, and if he's unable to do that, to take his dog out of the store. That's one of the reasons I dislike retractable leads: for every person who uses one responsibly, there seems to be a minimum of three who don't. And don't even get me started on people who allow their children to run around with untrained dogs on retractable leads. I've had too many encounters with kids who think it's fun to let the dog run to the end of the lead and then can't retract the lead safely when necessary--or just don't bother to do so while their dog takes off after anything and everything and everyone else just has to get out of their way.
For that matter, in a store where a dog on a thirty foot lead could knock things over or startle other people by nosing them or jumping up on them, a thirty food lead is just a bad choice, and I wouldn't think it was inappropriate for the store or its manager to request that the owner in question keep his retractable lead at a maximum of six feet, and if he's unable to do that, to take his dog out of the store. That's one of the reasons I dislike retractable leads: for every person who uses one responsibly, there seems to be a minimum of three who don't. And don't even get me started on people who allow their children to run around with untrained dogs on retractable leads. I've had too many encounters with kids who think it's fun to let the dog run to the end of the lead and then can't retract the lead safely when necessary--or just don't bother to do so while their dog takes off after anything and everything and everyone else just has to get out of their way.
