Two dogs that are contesting possession of a highly valued resource for the first time, if one is in a state of emotional arousal, in pain; if reactivity is influenced by recent endocrine changes, or motivational states such as hunger, then the outcome of the interaction may be different than if none of these factors were present. Equally, the threshold at which aggression is shown may be influenced by a range of medical factors, or, in some cases, precipitated entirely by pathological disorders. Hence, the contextual and physiological factors present when two dogs first encounter each other may profoundly influence the long-term nature of the relationship between those dogs. The complexity of the factors involved in this type of learning means that dogs may develop different "expectations" about the likely response of another individual for each resource in a range of different situations. Puppies learn early not to challenge an older dog and this respect stays with them into adulthood. When adult animals meet for the first time, they have no expectations of the behavior of the other: they will both, therefore, be initially anxious and vigilant in this encounter (characterized by the tense body posture and sudden movements typically seen when two dogs first meet), until they start to be able to predict the responses of the other individual. The outcome of these early adult–adult interactions will be influenced by the specific factors present at the time of the initial encounters. As well as contextual and physiological factors, the previous experiences of each member of the dyad of other dogs will also influence their behavior.[34] dog training classes
In 2012, a study found that dogs oriented toward their owner or a stranger more often when the person was pretending to cry than when they were talking or humming. When the stranger pretended to cry, rather than approaching their usual source of comfort, their owner, dogs sniffed, nuzzled and licked the stranger instead. The dogs' pattern of response was behaviorally consistent with an expression of empathic concern.[16]
Resource guarding is exhibited by many canines, and is one of the most commonly reported behaviour issues to canine professionals.[50] It is seen when a dog uses specific behaviour patterns so that they can control access to an item, and the patterns are flexible when people are around.[51] If a canine places value on some resource (i.e. food, toys, etc.) they may attempt to guard it from other animals as well as people, which leads to behavioural problems if not treated. The guarding can show in many different ways from rapid ingestion of food to using the body to shield items. It manifests as aggressive behaviour including, but not limited to, growling, barking, or snapping. Some dogs will also resource guard their owners and can become aggressive if the behaviour is allowed to continue. Owners must learn to interpret their dog's body language in order to try to judge the dog's reaction, as visual signals are used (i.e. changes in body posture, facial expression, etc.) to communicate feeling and response.[50] These behaviours are commonly seen in shelter animals, most likely due to insecurities caused by a poor environment. Resource guarding is a concern since it can lead to aggression, but research has found that aggression over guarding can be contained by teaching the dog to drop the item they are guarding.[51] go here for more