Dogs are highly social animals and are well adapted to living in groups. Studies have also shown that they are very good at interpreting human gestures and behavior. Dogs interact with each other and people through body postures, facial expressions, tail and ear positions, raising of hair or "hackles," vocalizations, and scents. Although dogs evolved from the grey wolf 12,000-14,000 years ago, domestication and breeding practices have created variations in appearance, temperament, and social signaling. These variations can make it difficult for dogs and people to communicate with different breeds. Early and frequent socialization with many different dogs can help improve a dog's ability to interact with other dogs and people.
Between 3 to 8 weeks of age, dogs tend to focus on other dogs (if available) for social interaction, and between 5 to 12 weeks of age they shift their focus to people. Dogs are most receptive to learning how to deal with new situations until about 16 to 20 weeks of age. After this age, dogs do not stop learning from exposure; they just do so at a much slower rate and perhaps in a different way. It is not critical to change the focus of exposure at one specific period, because given adequate opportunities, puppies will learn about the social and physical environments when they are ready. Dogs that are kept exclusively kenneled or not exposed to people by 14 weeks of age may have severely undeveloped social skills. The best age to adopt a puppy is at about 8 weeks of age. Unless there is no other choice, puppies should not be adopted until at least 7½ weeks of age.
Sexual maturity in domestic dogs occurs between 6 to 9 months of age (later for giant breeds), while social maturity develops at 12 to 36 months of age. In free-ranging groups, dogs that challenge the established social hierarchy may leave and form their own groups if they do not succeed in gaining a high rank. This situation may be similar to one form of inter-dog aggression that occurs in multiple-dog households (see Behavior Problems in Dogs : Behavior Problems Associated with Aggression in Dogs). Social maturity is also the time when problems with aggression and anxiety develop. Roaming, mounting, urine marking, and fighting are stimulated by sex hormones, particularly testosterone. These problems are often greatly reduced in males by neutering.
Most domestic dogs, except for Basenjis, have 2 heat (estrous) cycles per year. All members of the group may assist in puppy care. In multiple-dog groups, the highest-ranking dogs may be the only ones to breed.
Although the dog's social structure has been referred to as "pack hierarchy," it is not an accurate description of dogs' relationship with each other or with people. Hierarchy in dogs is not set in a straight line. Instead, it flows based on what resource the animals desire. It is maintained primarily by lower-ranking dogs giving way to higher-ranking ones and not, as commonly believed, by fighting. In addition, it only applies to a dog's relationship to other dogs, not to its interaction with people.
Your veterinarian and their staff can work with breeders, trainers, pet stores, and shelters to ensure that newly adopted dogs get off to the right start. For puppies, this includes advice on socialization, normal dog behavior (eg, jumping up, play biting, elimination) and how it can be managed, a household environment that provides appealing but safe outlets for all of the dog’s behavioral needs (eg, chewing, social play, object play, rest), advice on dog communication, and learning principles of reward-based training. The goal should be to reinforce desirable behaviors and to ignore or prevent unwanted behaviors. Clicker training can be particularly useful to immediately mark and reward desirable behavior and gradually teach behaviors that more closely approximate the final desired outcome (for example, relaxation). Chewing and biting are common problems, because puppies need to explore and play and use their mouths to explore their world. Therefore, providing constructive social activities that do not include mouthing or biting people, such as tug games, retrieving, walking and running, chasing, hide and seek, playing with other dogs, and training for rewards, gives the puppy something positive on which to focus. A head halter is also an option for better control of the head and muzzle. Another way to manage chewing and biting is to provide chew toys, food-stuffed toys, and food-dispensing toys. When the puppy cannot be effectively supervised, the household should be set up to ensure success (and avoid failure). Preventing undesirable behaviors while providing the dog with options acceptable to the owners and the dog gives the dog control to make choices, reduces uncertainty and anxiety, and prevents undesirable behaviors. Of particular value to establish a safe haven is a crate, exercise pen, or room to provide security and safety for the dog when it cannot be supervised or wants to be alone. A daily routine can be established that provides stability and predictability for the dog, beginning with meeting the dog's social and physical needs, followed by sessions of inattention during which the dog is given the opportunity to nap and rest or to engage in exploratory play with its food and chew toys. By confining the dog to a crate, pen, or room during these “inattention” times, the dog learns to spend time on its own; this also may prevent damage to property, housesoiling, and even separation anxiety. Undesirable behavior might alternatively be prevented through environmental management (eg, child gate, shutting doors, tie downs, deterrent devices). Neutering males may also help to prevent testosterone-influenced behaviors such as urine marking, mounting, and roaming.