Pet advice: Why do dogs like things that smell bad? It’s all about biology

Q: Our dog Grolsch likes to roll in anything that smells gross –– cat poop, especially. He even likes dead lizards and rotten garbage. Is he just being disgusting or is there a reason for this behavior?

A: Just because our dogs can smell 100,000 times better than we do doesn’t mean they’re better arbiters of smelly goodness.

Sure, they can whiff out a drop of blood in a hundred gallons of water or detect cancer cells, making our sense of smell seem rudimentary by comparison, but they have a penchant for the putrid, as well.

Foul as they are, animal feces (especially those of wild carnivorous mammals like raccoons and opossums) clearly offer dogs a scent sensation. So, too, for cat poo, a delicacy few dogs will turn up their noses at.

But it’s not just poop. Rotting corpses, decaying flesh and fetid bodily fluids elicit similarly delighted reactions. Not only do they seem magnetically attracted to these aromas, most dogs actively seek ways to keep them around. I mean, why else would an animal who can smell hundreds of millions of odors elect to roll in ferret feces (of all things)?

Turns out there’s a biological rationale for this. It’s been suggested by scent scientists and wildlife biologists that they engage in this behavior so they can mask their own canine scent. Here’s why:

The strong aroma of carcasses and decay creates a sensory explosion for animals who rely on their snouts for sustenance. Rolling in the stuff means they can throw predators off their trail and keep prey in the dark about their doings. All this so they can eat well, unencumbered by the competition other carnivores might offer.

I know it’s gross. But it makes sense, too. The history of the natural world is full of examples in which one organism will cover itself in another’s scent. Whether it’s for some form of protection or to confer another sort of evolutionary advantage, the bottom line is that another animal’s scent is useful for subversion, survival and in some cases, seduction. Why else would we humans think that dousing ourselves in exotic fragrances makes us more attractive to the opposite sex?

Sure, the smell of cat poop may seem like taking things a tad too far, but as I always like to say, there’s no accounting for taste, especially where our pets are concerned.

Dr. Patty Khuly has a veterinary practice at Sunset Animal Clinic in South Miami. Her website is Send questions to