Why Small Dogs Go Above and Beyond to Mark Their Territory

To dogs, urinating is more than just a mundane daily task. As veterinarian Marty Becker explains, the act serves as a key mode of canine communication, allowing pups to mark their territory and scope out the neighborhood’s competition.

It’s logical to assume that dogs wield little control over the information conveyed by their urine, but a new study published in Journal of Zoology suggests otherwise.

Scientific American’s Julie Hecht reports that researchers led by Cornell University’s Betty McGuire found that small male dogs tend to lift their legs while peeing in order to deposit urine at a higher angle and appear larger than their actual size. This tactic may be a way for smaller dogs to “exaggerate their competitive ability” relative to larger dogs, the study notes.

To gauge the relationship between urination angle and dog size, the scientists turned to two local animal shelters. They borrowed an assortment of juvenile and senior male dogs, set out on walks with cameras in hand, and recorded the pups’ peeing angles in relation to the actual height of their urine marks.

The team discovered that smaller dogs peed at proportionately higher angles than big dogs, going out of their way to leave marks at these higher levels.

“Small males seemed to make an extra effort to raise their leg high—some small males would almost topple over,” McGuire tells New Scientist’s Jake Buehler.

When bigger dogs urinated, the height of their pee marks tended to accurately reflect size. When it came to small dogs, however, the researchers report that the crafty canines appeared to “‘cheat’ by increasing their raised-leg angles to deposit higher urine marks, thereby exaggerating their size.”

One dog tested—a black-and-white pup fittingly dubbed Patches—initially raised his leg at a 115-degree angle, leaving a urine mark at a height of six inches. During the same urination, Patches then raised his leg to a 120-degree angle, leaving a mark at a height about an inch higher.

According to Scientific American’s Hecht, there are several potential explanations for smaller dogs’ trickery. Since dog pee conveys an array of information, including sex, age and reproductive status, it’s easy for a pup to tell if he’s entered an unfamiliar dog’s territory. Faced with the scent of an apparently larger dog, it may be prudent for smaller dogs to avoid direct confrontation by exaggerating their own size.

Another possibility is that smaller dogs raise their legs to extreme heights in order to “over mark,” or cover another dog’s pee with their own, although the researchers acknowledge that they did not account for this scenario in their study.

As Gizmodo’s Ryan F. Mandelbaum concludes, the new findings can be interpreted in a number of different ways. The discrepancies between smaller and larger dogs’ leg lifts could just be the result of anatomy, with larger dogs proving less adept at lifting their legs to great heights. Only time—or further observation of dog urination techniques—can tell.

Meilan Solly | | READ MORE

Meilan Solly is Smithsonian magazine's senior associate digital editor, history.