Small Dogs Use This Ploy to Exaggerate Their Size and Competitiveness

small dog pee

Story at-a-glance -

  • Dogs scent mark (urinate) to communicate all kinds of interesting information to other dogs in the area
  • Recent research suggests small dogs may lift their legs higher when scent marking on vertical surfaces to trick other dogs into thinking they’re bigger
  • An earlier study concluded small dogs also scent mark more frequently, perhaps because they have more to lose if a nose-to-nose communication with a larger dog proves threatening

By Dr. Karen Shaw Becker

Recently, a group of researchers at Cornell University published a study in the Journal of Zoology intriguingly titled “Urine marking in male domestic dogs: honest or dishonest?”1 In many species (excluding humans, presumably!) peeing is a form of communication, also known as scent marking. Mammals perform the behavior to give passersby information about them, including their ability to compete for resources.

Why Dogs Scent Mark

Here’s how explains the purpose of scent marking in dogs:

“Communications can occur because dogs have very keen noses and brain parts able to tease out specifics from other dogs simply by sniffing their urine. By sniffing the pee left by another dog, dogs can learn a lot about the dog that did the peeing — such as its gender, age, fertility and some aspects of its health. These communications occur as a means for dogs to learn more about other dogs in the area, both male and female.”2

A pioneering 2011 study3 suggested dogs of both sexes use a variety of different urination activities to:

  • Assert social status or position
  • Find potential mates
  • Size up unfamiliar dogs
  • Limit potentially threatening close contact during social introductions

The researchers believe dogs may use urine investigation and scent marking to establish safe social connections with other dogs. Study co-author Anneke Lisberg, Ph.D. told Discovery News it’s possible dogs “might be able to assess many personal aspects of health, stress, virility, diet" and more just by sniffing another dog's urine.4

Lisberg believes marking and countermarking could be "a sort of Facebook of their personal life, easily accessible from a safe distance."

Do Small Dogs Pee Higher to Exaggerate Their Competitive Ability?

Scientists have historically assumed scent marking is an accurate reflection of the pee-er’s physical attributes, but it turns out that may not be the case with every dog. The Cornell researchers set out to test the possibility that urine may actually be a dishonest signal in adult male dogs when they raise a back leg to pee on vertical objects.

In the first study, the researchers wanted to see if the angle of the dogs’ raised legs was a representation of the height of their urine marks. In the second study, they observed small dogs to see if they raise their legs higher than larger dogs. The researchers videotaped all the peeing activity and then measured the height of urine marks from study No. 1 and the degree of raised-leg angles from both studies.

The results of the first study showed a significant positive relationship between the angle of the raised leg, the height of the urine mark and the size of the dog. The angle of the raised leg was actually a better predictor of the dog’s size than either body mass or height at the shoulders.

In study No. 2 with the small dogs, the researchers found a significant negative relationship between body size and average raised-leg angle, meaning the little guys raised their legs unusually high compared to the larger dogs. The researchers concluded scent marking in dogs can be dishonest. They wrote:

“Assuming body size is a proxy for competitive ability, small adult male dogs may place urine marks higher, relative to their own body size, than larger adult male dogs to exaggerate their competitive ability. We did not control for over marking, which also may explain our findings.”5

Small Dogs Also Do More Scent Marking Than Bigger Dogs

In an earlier study, two of the same Cornell researchers involved in the above research set out to test their assumption that smaller dogs might scent mark more often than larger dogs because they have more to lose if a one-on-one interaction with another dog goes bad.

This assumption challenges the popular notion that competitive dogs do more scent marking than less assertive dogs. The study involved 281 shelter dogs.6 The researchers observed the dogs on 20-minute walks and kept track of total urinations, peeing directed at specific targets in the environment, and also defecations. The researchers walked some of the dogs once and others multiple times, for a total of 619 potty-walk observations.

The researchers discovered that small dogs pee at higher rates (0.36 urinations per minute) than both medium (0.26) and large dogs (0.24). The little ones also directed more of their urinations at targets in the environment (72 percent) than large dogs (60 percent). The researchers also confirmed the results of previous studies that showed male dogs pee at higher rates (0.41) than females (0.18), and direct more of their urinations at targets in the environment (87 percent versus 45 percent for the ladies).

Pooping for all the dogs was random, having nothing to do with size or sex, which makes sense since defecation seems to play a much less important role in scent-marking than urination, at least among canines. The researchers also noted that dogs who had been at the shelter longer did more frequent targeted peeing, and were also more likely to poop on their walks. The researchers concluded:

“Our findings regarding body size and urinary behavior support the hypothesis that small dogs communicate more frequently via scent marking than larger dogs. Body size is known to influence visual and auditory communication in mammals, and our data show that body size also influences chemical communication. Finally, our results provide context for problematic marking behaviors in the home.”7

Of course, the smaller size of small dogs’ bladders can sometimes account for more frequent peeing, but it doesn’t explain the targeted aspect of scent marking.

The takeaway from this study: Small dogs prefer scent marking and do more of it because it’s less risky for them than direct interactions with other dogs. They’re able to avoid conflict through sniffing and marking, so allowing your dog to exhibit this natural behavior on walks is important.