More times than I can remember, I've been out walking my pack of 3+ dogs and someone, out for some exercise, has stepped off of the sidewalk and knelt down, awaiting my pack to land in their wide-open arms. As we pass them by, empty armed, I can see their look of disappointment as well as hear the occasional comment: "are you in a hurry or something?"
Other times, I'm out and instead of a human looking for some affection, it's a person wanting their dog to meet mine. "She likes other dogs," she shouts, as this hyper dog, on the end of their leash, is dragging their owner over to my dogs. Again, I wave and scoot on by with my pack before the impending collision happens. To this, I get a disappointing look and probably some not so kind mumbles.
My efforts to not greet other people and dogs while on a walk are not to be rude, or anti-social, but to protect my pack AND the person or dog coming in for the "hug". Greeting a strange group of dogs on leash is not safe. Many dogs are extremely friendly, however the person who is walking the dogs has a lot of responsibility to be in control, regardless if it is one or 20 dogs! That said, by someone pushing them self on a group or even just one dog, they are disturbing the pack dynamic in place. Some dogs may do just fine with a random person wanting to snuggle them up, but some may be nervous of an impending stranger and bite, or some may become jealous of each other receiving affection and start fighting. For everyone's safety, you don't know what to expect when you see someone with their dog(s), so you can't assume that you are welcome to touch or interact with them.
As the dog's walker, it's important that you think about what is best for your dog. Can you control your dog(s) to meet another person or dog? What message does it send to your dog if you're asking them to be structured, calm, and well-behaved while you're on a walk, but allow them to get over-excited as they meet someone or another dog? Will they start pulling you over to meet the next stranger that walks by, because "that's what we do now?" Allowing your dog to dictate when it's time to stop and socialize ultimately discredits you as the in-control pack leader your dog needs you to be.
The same rules apply to dogs meeting other dogs on leash. Leash to leash greetings are the worst of all, because you have two (or more dogs) circling each other and sniffing, while their owners hold their leashes tightly. The tension on the leash and collar, creates tension in the dog and can cause a negative response. This scenario is why many people say "my dog can socialize with other dogs at the off-leash dog park, but when they see another dog on our walk they go ballistic." The leash receives tension from the dog pulling and sniffing, thus creating a tense dog that may make a bad choice (like snapping, mounting, challenging, or fighting another dog).
Instead of trying to make dogs "shake hands" with each other in an on leash setting, like while on a walk or a dog training class, try moving together in the same direction. Create a little pack! Trust me, a dog's sense of smell is 100,000 times more powerful than a human's--they can smell each other from 3 feet away. They don't need to be in each other's personal space to have a relationship. If you take a group of on leash dogs that need to socialize, and start migrating them as a pack, they will begin to relate to each other on a primal level while still being influenced and under the control of their pack leader--YOU!
Save the personal space greetings for when your dog can be off-leash, without the tension of the leash in the way of their decision making. If your dog can't be trusted off-leash with other dogs--that's ok! These on leash pack migration movements will give your dog some relationship time with other dogs, regardless of if they are sniffing butts or not. Be aware of the influence you are giving your dog--a loose, relaxed leash makes for a relaxed dog. A tight, tense leash makes for an uncomfortable and tense dog. If you can be the pack leader, in control of your dog and his surroundings, you'll have a happy dog who trusts what situations you're putting him in!