Scent marking is a very normal and common behavior particularly in male dogs, but becomes a big problem when marking occurs in the home. Dogs mark to advertise their presence or to claim territory and resources. Pheromones in urine and feces contain chemical messages that pass on information about the marker such as age, sex, health and reproductive status. Even though urination has a competitive component, it can also occur if a dog is over stimulated, for example, during or after vigorous play, or if a dog becomes anxious in a particular situation, such as when a person leaves. This common expression of anxiety in dogs is often mistaken for spite, resulting in punishment that only serves to increase anxious behavior.
Both sexes scent mark, but intact males are the worst offenders as signaling sexual availability and claiming territory is ‘encouraged’ by the presence of testosterone. In many cases, neutering can significantly reduce the desire to scent mark, but some dogs continue even after they have been neutered. Resources such as toys, food bowls, chew treats, bones and beds are the most likely objects to be marked and in some cases, a dog will actually mark a person or something that smells heavily of that person such as a sofa or bed.