Why Does a Dog Pee Over Where Another Dog Just Peed?

When your pup urinates on another dog’s puddle, he is, in a sense, “canceling out” that dog’s mark on what he perceives to be his territory. Your dog may do this to strange dogs he meets in public, to neighbor dogs or even other dogs in his household as a way to establish territory and assert dominance. Your dog considers the act a form of branding meant to say to other dogs, “Stay out. This is my turf.”

Unaltered dogs, males in particular, are more likely to urinate on another male’s urine to take him out of the running for available local females. After all, if she can’t smell him, she might not be able to find him. That same dog also might mark a female’s urine to mask its odor and discourage any would-be male suitors. It's not uncommon for females to exhibit this behavior, especially prior to her heat cycle.

Dogs consider the house their territory, and if you bring home a new puppy who has accidental piddles during housebreaking, your older dog is sure to take notice. He may pee on the puppy’s accidents as a way to show her who the house belongs to. It could also be out of anxiousness -- if your pup thinks a newcomer, whether a permanent resident or a visitor, is a threat, marking is a way to make sure the house smells like him and only him.

While outdoor marking probably doesn’t matter to you, if your dog decides to pee in your house, or in someone else’s house as a way to establish dominance or mark territory, you’ll have to step in. For starters, clean your carpets with an enzymatic cleaner to remove any trace of urine from dogs or cats that were there previously. If your dog marks, clean that up, too. Consider getting your dog fixed to cut down on the problem -- it also will make him or her less likely to roam and get into trouble.