"Misreading a dog's emotional state can be distressing for its human family, and can even be fatal for the dog," writes Stanley Coren in his book How to Speak Dog: Mastering the Art of Dog-Human Communication.
Dogs behave the way they do for a variety of reasons: boredom, fear, protectiveness. A dog behaving aggressively may be a mean dog, or he may be a beloved pet that is defending his territory, his toy, or his food. He may be afraid, or in pain. A dog destroying property or leaving a mess for the owners to come home to may have too much energy for his time alone, may not understand that what he's doing is unacceptable, or may have a medical situation that needs to be addressed.
Unfortunately, too many dogs are taken to shelters or put to sleep because of behavior. As long as there is not a medical problem causing the behavior, owners can usually resolve behavior issues by resolving the cause behind the behavior. Sometimes, adjusting the dog's living space can help; in some cases, advice from a professional trainer should be sought.
Behaviors humans often misunderstand:
A favorite adage says a dog's friendly if its tail is wagging, but like most simple statements, it leaves out important parts. Dogs use their tails to communicate many things, friendliness as well as fear, uncertainty, and even aggression.
One type of tail wag, with enthusiastic and vigorous movements that often include the hips, indicates friendliness. Another is a slower, stiff movement which is given as a warning, in much the same way teeth baring and growling are warnings to back off and leave the dog alone.
Dogs do like to be close to their owners. They prefer to be in the same room, under the table or desk where the owner is. However humans sometimes also interpret their dog sitting against or leaning against them as affection. In dog pack hierarchy, the dominant dog sits where he pleases and everyone else moves. When a dog sits so close or leans in such a way the owner is forced to move, the dog is claiming his way, his will, takes precedence over his owner.
While a dog making eye contact with his owner does it, or is trained to it, to show he's paying attention and understanding, prolonged periods of eye contact, particularly between an unfamiliar dog and a human or two dogs just meeting, may be perceived as a challenge. A submissive dog will gaze at his owner, then drop his eyes. A dominant dog will wait for the other to break eye contact first, and can act aggressively if the eye contact is sustained too long.
It never fails, just when the owner thinks housetraining is complete, the dog urinates all over the rug. But before housetraining is deemed a failure, owners should be sure the dog isn't suffering from a medical issue causing it. The dog may also be urinating to signal his submissiveness.
Rather than an attempt to retaliate or annoy an owner, chewing on something is often a dog's way to wait through the day until the owner comes home. Destructive chewing could be a sign of boredom, a signal the dog needs more time with his human companion, and certainly more stimulation and appropriate places to put his energy while waiting at home. Or the dog may be suffering from separation anxiety.
Stanley Coren. How to Speak Dog: Mastering the Art of Dog-Human Communication, 2007.
Humane Society of the United States. Dog Behavior Tip Sheets. Retrieved April 10, 2008. http://www.hsus.org/pets/pet_care/our_pets_for_life_program/dog_behavior_tip_sheets/