Your male dog is most likely peeing on your other male dog as a form of scent marking, specifically a behavior called “overmarking” or “countermarking.” Dogs communicate heavily through scent, and urine is their primary tool for broadcasting social information. When one male urinates on another, he’s essentially trying to cover the other dog’s scent with his own, a move closely tied to social status and competition.
Scent Marking Is Dog Communication
Urine marking is the most common form of scent communication in dogs. Every time your dog lifts his leg on a fire hydrant, a tree, or another dog’s pee spot, he’s leaving behind chemical signals that tell other dogs about his identity, sex, health, and social standing. Dogs can extract a remarkable amount of information from a single urine mark.
Overmarking, where one dog places his scent directly on top of another’s, takes this a step further. It’s essentially a way of saying “I was here last” or “my signal matters more.” Both sexes do this, but males overmark significantly more than females. Research published in the journal Animals found that competitive countermarking is strongly connected to social status, meaning dogs may assess the rank of other dogs just by sniffing their marks.
When your dog pees directly on your other dog (rather than just on his urine), he’s applying that same instinct to a living, moving target. The other dog IS the scent source, so marking him is the most direct way to cover that scent.
Social Status and Competition Between Males
In a multi-dog household, your dogs are constantly negotiating their social relationship. Peeing on the other dog is one of the more obvious ways a male dog tries to assert higher status. It’s not necessarily aggression, but it is a dominance-related display. The dog doing the marking is communicating that he considers himself socially above the other dog, or at minimum, he’s competing for that position.
This behavior tends to be more common in certain situations: when a new dog enters the household, when both dogs are intact (not neutered), when there’s competition over resources like food, toys, or your attention, or when one dog feels his position in the household is uncertain. Changes in your home, like a move, a new family member, or even rearranging furniture, can trigger a spike in marking behavior because the social landscape suddenly feels less settled.
Some dogs also overmark another male’s scent specifically around female dogs, even spayed ones. Research suggests this mate-guarding behavior can be reinforced by aggressive encounters and dominance displays between the males.
Hormones Play a Major Role
Intact (unneutered) male dogs are far more likely to engage in urine marking of all kinds, including marking other dogs. Testosterone drives much of the territorial and status-signaling behavior behind it. Early studies on neutering found the surgery could reduce marking behavior by up to 80% in male dogs, along with decreasing roaming, mounting, and intermale aggression.
That said, the picture is more nuanced than “neuter and it stops.” A 2017 study found no significant differences in mounting, overmarking, or leg-raised urination between neutered and intact males. The timing of neutering matters, as does how long the behavior has been practiced. A dog who has been marking for years has a well-established habit that may persist even after hormone levels drop. Neutering tends to work best when done before the behavior becomes deeply ingrained.
Anxiety and Insecurity Can Trigger It
Not all marking is a confident dog asserting himself. Sometimes it’s the opposite. A dog who feels anxious or insecure in a multi-dog household may ramp up marking behavior as a way of coping with perceived threats to his position. If your dog marks the other dog more after stressful events, during changes in routine, or when other animals are nearby outside, anxiety is likely part of the equation.
Outdoor triggers matter too. If unfamiliar dogs are visiting or passing near your property, your dog may feel increased pressure to mark everything in his territory, including your other dog. Investigating the perimeter of your home for signs of visiting animals can help you understand sudden increases in marking.
Rule Out a Medical Problem First
Before assuming the behavior is purely social, it’s worth checking whether a medical issue is involved. Urinary tract infections, bladder stones, and other conditions can cause a dog to urinate more frequently and in smaller amounts, which can look a lot like marking. According to Cornell University’s veterinary program, common signs of a UTI include straining to urinate, frequent small urinations, foul-smelling urine, excessive licking of the genitals, and blood in the urine.
If the peeing-on-the-other-dog behavior appeared suddenly, or if your dog is also having accidents in the house, urinating more often than usual, or showing any of those symptoms, a vet visit should be your first step.
How to Reduce or Stop the Behavior
Supervision is the most effective immediate tool. If you can’t watch your dogs interact, separate them using crates, baby gates, or different rooms. When you are watching and you catch the marking dog in the act, make a sharp noise to interrupt him, then immediately redirect him outside and reward him for urinating in the right place.
Timing matters enormously here. If you find evidence after the fact, punishing your dog will not help. Dogs cannot connect a punishment to something they did an hour (or even five minutes) ago. Delayed punishment only creates fear and confusion, not behavior change.
Clean any spots where marking has happened with an enzymatic pet stain remover. Standard household cleaners won’t fully eliminate the scent to your dog’s nose, and lingering odor draws him back to mark the same spot again. For a temporary management tool, belly bands (wraps that fit around a male dog’s midsection) can prevent urine from reaching its target, though they don’t address the underlying motivation.
Reducing competition between the dogs can also help. Feed them separately, give them their own resting areas, and avoid situations where they’re directly competing for your attention. If the behavior is rooted in social insecurity, giving each dog his own space and resources removes some of the pressure driving the marking. For persistent cases, working with a veterinary behaviorist can help you identify the specific dynamic between your dogs and build a targeted plan.