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Why Do Dogs Love Things That Smell Bad to Humans? Vet-Verified Facts

Written by: Cassidy Sutton

Last Updated on April 16, 2024 by Dogster Team

dog smelling and sniffing a car's wheel

Why Do Dogs Love Things That Smell Bad to Humans? Vet-Verified Facts


Dr. Paola Cuevas Photo


Dr. Paola Cuevas

Veterinarian, MVZ

The information is current and up-to-date in accordance with the latest veterinarian research.

Learn more »

“Ew. Why does my dog do that?” It’s a question every dog owner has asked at least once. Dogs like to stick their noses where it, quite literally, doesn’t belong—inside garbage cans, in a large pile of poop, and up other people’s behinds (unfortunately).

Most of the time, the things dogs love to smell don’t actually smell very good. But why do dogs love it so much? There’s a simple, scientific explanation, and you’re about to discover why.


Smelly Smells: Gross or Necessary?

If you look at a cat, a rabbit, or a horse, they don’t seem to care for disgusting smells as dogs do. Even if the animal has a strong olfactory sense like the dog, canines still prefer foul odors. That’s because, for dogs, foul odors proved necessary for their survival before becoming domesticated.

dogs sniffing each other
Image By: Diederik Hoppenbrouwers, Shutterstock

Scent Masking

Dog behaviorists believe that dogs roll in smelly objects such as carcasses and feces to wear the scent like perfume. This goes back to the dog’s wolf ancestry.

Ultimately, foul odors are more pungent than pleasant odors, making them better for masking scent from nearby prey. This proved to be effective when wolves hunted for food. The behavior remained with domestic dogs.

Marking Their Findings

Dogs also use foul odors to claim objects or mark their findings, like urinating on a pole or defecating in their yard. Most of these nasty odors come from bodily fluids carrying identifying scents unique to the dog.

Dog Pee Tire
Image By: KANUT PHOTO, Shutterstock

Discovering Other Scents

Dogs interpret the world through their noses like how humans use language. Sniffing is how they communicate with other dogs, understand when it’s time to mate and protect themselves from danger.

Above communicating with other dogs, sniffing is like solving a puzzle. Dogs consider the scent and compartmentalize the information in their brains. The missing pieces are yet to be discovered.

A life without sniffing is like a life without words for dogs. Their livelihood and happiness rely on a good sniff now and then, even if that scent is deemed undesirable to our noses.

What Dogs Have That Humans Don’t

One of the biggest reasons why dogs love things that smell is their unique olfactory sense. Their sense of smell is 1,000 to 100,000 times greater than a human’s.

Inside a dog’s nose are 100 million sensory receptors that welcome any and all scents, good and bad. Any time a dog sniffs something, the sensory receptors send the information directly to the brain, which processes the information.

But what separates a dog’s sense of smell from a human’s is the Jacobson’s organ. The Jacobson’s organ, or the vomeronasal organ, serves as a secondary olfactory sensor and provides information typically considered invisible to the human nose. It’s no wonder dogs excel at finding hidden drugs, missing persons, and even sniffing out lung cancer.

dog nose close up shot
Image By: Miranda, Pixabay

Should I Let My Dog Sniff Smelly Things?

Dogs are wired for smell, so allowing your dog a chance to sniff is a good idea. That doesn’t mean your dog needs to eat poop or bring the dead animal scent into your house, though.

Instead, you can make your dog’s walk more enjoyable by stopping and letting your dog sniff. Keep a close eye on your dog so it doesn’t find feces, moldy food, or roadkill.

You can also take up a dog sport or play a sniffing game with your dog. Place “smelly” objects hidden in a few boxes, like treats and dirty T-shirts, then let your dog go crazy with sniffing.



Can you imagine exploring the world without the chance to ask, “What’s that?” or “Who did it?”

That’s exactly what dogs do when they sniff and roll. The behavior is their way of interpreting the world. It’s hard for humans to grasp a hold of, considering it’s gross most of the time, but that makes humans and animals unique.

We all have our way of seeing and dealing with the world. Sniffing bad smells? That’s just the canine way!

Featured Image Credit: Damix, Shutterstock

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