Very few dogs live in splendid isolation. They almost all encounter others of the same species throughout the course of their lives. Sometimes meetings between dogs take place on the street, sometimes they occur at public or private events, and sometimes they occur in the privacy of one or other dog's home or yard.
How a dog responds to such a meeting depends on a number of factors, such as the dog's temperament, his level of socialization, previous experience with other dogs, the other dog's behavior, the location that the meeting takes place, whether he is on lead (controlled) or free, and (not least) the presence or absence of his owner. All this can paint a pretty confusing picture for the owner who often has no idea whether a particular meeting will be friendly or hostile.
When a couple of well-balanced, well-socialized, happy-go-lucky dogs meet, the result is often pure joy on the part of both dogs. They may run excitedly toward each other tails raised and wagging, mouths held relaxed, partly open, with lips slightly retracted (almost smiling), and with tongues lolling from side of their mouths. On establishing close contact, they proceed to investigate each other using every single sense to familiarize themselves with their new contact. Vision plays a key role in such recognition. They recognize a smiling face and relaxed body posture in another dog, as we do in a friendly stranger, and know when it's safe to proceed. Next they sniff one another. As odd as it may seem to us, "anogenital" investigation is a natural, mutual greeting through which personal data is exchanged. The dogs then engage in a more physical greeting, perhaps licking, pawing, or body rubbing against each other. Their mutual appreciation endorsed, they may then signal a desire to play by means of ritualistic play bows and they're off to the races.
Sometimes dogs are not immediately friendly. For reasons of mutual suspicion and the need to establish rank, they progress through a series of subtle challenges and necessary responses in order to establish an understanding. The most forward or challenging dog often approaches the other at right angles, body tense - ready for action, vision riveted, ears erect, and tail flagging. The other dog has several options ranging from returning the challenge to extreme deference or even running away. For the challenged dog to swiveling around to stand parallel to its challenger, even resting its head on other dog's rump, is not necessarily cause for alarm at this stage of the proceedings – but from here things can escalate.
Challenge and response is layered on, often in fairly short order. A paw placed on a shoulder, a close up stare, even a growl, may be met with escalation upon escalation, leaving no option but for a fight to break out. Alternatively, as is most often the case, one of the pair folds, adopting a slightly more deferent posture or literally rolling over to signal his acquiescence. After this crucial exchange of hierarchical acknowledgement, the fun can begin. Owners are often surprised when the seemingly confrontational beginning of a relationship soon turns into play.
Some dogs are never happy to meet a new dog. Perhaps because they were deprived of social interactions with other dogs during a sensitive period of development (3 to 14 weeks of age) and never learned to trust. Or perhaps because of some profoundly negative experience with another dog, they prefer human company or just being alone, to being around their own kind. On seeing another dog, even at a distance, such dogs become tense and act in such a way as to deter the encouter. They stiffen and bark at the other dog with hackles raised and tail tucked. Even humans know what these dogs are trying to communicate - but still some dogs continue to approach. This is when real trouble can arise as the dysfunctional dog attempts to repel borders.
If a fearful dog is on a lead with a flat collar or choke collar, its aggressiveness is often augmented because any chance of escape is thwarted. That leaves a good offense as the best defense. However, if the owner's leadership is signaled to the dog by means of a head halter system, the dog may well yield to the owner's masterly control and permit introductions to be made. Then, at least, the dog can begin the process of learning not to be fearful other dogs. Dogs that are wary of other dogs are not always alone in the world when it comes to dog friends. They often have accepted one or two other dogs into their inner sanctum of trust and may enjoy their company. It's newcomers that they prefer not to meet.
Where Meetings Take Place
Most confrontations occur when dogs are introduced on one or other dog's home turf (territory). For a dog, territory is not simply what is defined in the owner's plot plan but rather extends up and down neighboring streets, especially anywhere the dog urine marks, and includes the owner's car. For the best chance of success when attempting to familiarize strange dogs is to introduce them away from either dog's territory and under pleasant circumstances. Later, once they have had a chance to interact and have shown that they can get along together, they can be brought back to one or the other dog's home.
If a dog trusts his owner to look after him, he will be less aggressive with other dogs and will be more likely to respond peacefully to potentially provocative encounters with other dogs. It's as if the dog knows that his owner will protect him, and he gains confidence from that fact. Many owners misunderstand their dog's aggressiveness to other dogs as signaling its protectiveness of them whereas, in fact, the dog is more likely protecting itself, believing his owner to be incompetent in this respect.
Dogs are social animals and, as such, normally enjoy the company of other dogs. In order to get to know other dogs, of course, they first must meet them and then appreciate them ... or not. Just because dogs are social creatures does not mean they will therefore enjoy the company of all other dogs they meet. Barring occasional posturing that goes on during some encounters, there is usually little to be concerned about when dogs meet. The only serious problems come when unsure dogs of near equal dominance status meet or when unwelcome meetings are forced on a dysfunctional, anti-social dog. To avoid such catastrophic meetings, it is important to know your dog, his strengths and weakness, to control the moment, and, above all, to be his strong and trustworthy leader.