Why do dogs like funky odours?

You don’t have to have a dog to appreciate this recent Slate column by writer Jesse Bering. But it helps. The article examines the reasons behind an unpleasant phenomenon familiar to most pet owners, and that is the domestic dogs’ affection for grinding against the funkiest and most foul-smelling objects they can sniff out.

Pigeon droppings, road kill, raccoon feces and just gooey, smelly trash—I’ve watched (in horror) as my dogs have rubbed their faces and backs into all of these items. The worst part: they do it with great enthusiasm. While I’m hosing them down in the bathtub later, I often wonder what it is my dogs find so appealing about these funky scents and textures. It appears I’m not the only one who scratches their head over this curious behaviour. Some researchers are actively trying to figure this little mystery out. 

Bering’s article touches on a few studies by animal behaviour specialists that have attempted to understand this strange canine tendency. (You can read about them in detail in his piece.) The interesting part about the studies, which include scent tests with wolves in Nova Scotia and spotted hyenas, is that even after the tests and the observation, researchers still have no real idea why dogs like to rub their faces and bodies in feces and road kill. 

They did come up with some interesting ideas though. For example, some believe that dogs distinguish between scents they like to ‘wear’ (sort of like vomit-inducing perfumes) versus scents that trigger their appetites (yes, some dogs like to eat feces). Another theory: they’re getting to know their environment by grinding in goo, almost like they’re downloading olfactory information with every rub. (The value of that information is up for debate, however.) 

Rubbing in stinky matter may also contribute to social unity in a group. The hyena researchers found that when a particularly stinky hyena returned to the group they got a great deal of attention. (How different humans must be from hyenas and dogs because there’s nothing more divisive than someone wearing too much perfume or cologne in an office or subway car.) 

No one may be able to explain why dogs do the nasty things they do. But on the brightside, the enduring mystery certainly gives pet owners something to discuss at the dog park.