Why Do Dogs Sniff Or Lick Car Air Vents? (Explained For Beginners)

Dogs sniff and lick car vents for several reasons, including curiosity, digestive discomfort, and agitation. 

Why are dogs always sniffing and licking everything? Is it safe to use your car vents with your dog in the car?

We have all these answers and more in today’s article! 

Here’s Why Dogs Sniff Or Lick Car Air Vents

Dogs lick and smell car vents because they carry strong scents and particles from the outside. Dogs have a powerful sense of smell, far surpassing their ability to see. However, dogs’ togues aren’t very powerful, and their licking car vents might signify distress. 

Dog in car sniffing
Dog in car sniffing

Dogs were first domesticated around 23,000 years ago. Many scientists believe humans and dogs primarily evolved alongside one another as mutually beneficial to one another. 

Although wolves and dogs differ physically, they share a keen sense of smell. In fact, several studies indicate that dogs can even smell stress from our sweat. Without seeing or being near the stressed individual, dogs could detect the stench of stress in sweat. 

Many believe a dog’s sense of smell is its most robust sense. 

Their sense of taste and sight is significantly worse than humans and other animals. Many experts believe dogs have a mere 20/75 eyesight. 

In comparison, humans have an average of 20/20 eyesight. Meanwhile, cats put us humans to shame with their ability to discern shapes even in the dark. 

To compete with their fellow hunters, dogs had to evolve an edge. That edge was their sense of smell. We’ve put their keen sense to good use in tracking down killers, and kidnappers, and even detecting trace amounts of drugs. 

We can expect to see our dogs sniffing the vent in our cars. But why do they so obsessed with licking our vents? 

The truth is dogs don’t have a good sense of taste and they don’t taste things as well as humans do. 

So, why do they lick your car vents? 

Dogs use their tongues for a variety of reasons. However, one key reason is to calm themselves and express excitement. 

We will discuss this more in the next section. Just keep in mind that dogs might lick vents to calm themselves in the car.


Why Are Dogs Obsessed with Licking Everything? 

Dogs use licking as a means of calming themselves and those around them. It can be a sign of affection or curiosity. However, it can be a sign of anxiety or a medical condition if they do it compulsively.

Dogs that impulsively lick people are probably trying to express curiosity, and affection or are trying to clean you. Mother dogs tend to lick their young to clean them, so your pup might just be trying to clean you up! 

However, their insistent licking can also be a sign of the following: 

  • An attempt to get you to throw up (share your food) 
  • Anxiety
  • Digestive disorders 
  • Boredom 

Your dog might be trying to calm themself if they’re insistently licking your air vents. Some dogs get very nervous while they’re in the car. 

All the different scents entering the car through the vents could confuse your canine. Their constant sniffing and licking might be an attempt to learn more about their environment. 

Why Are Dogs Obsessed with Sniffing Everything? 

Dogs sniff their surroundings to learn more about their environment. They sniff one another to introduce themselves and meet other dogs. Some experts call this the “canine handshake” and compare dogs sniffing their environment to us exploring our environment with our eyes. 

Dogs use their sense of smell to explore their surroundings. Since a dog’s sense of smell is its greatest sense, it’s its primary means of perception. 

A dog obsessively sniffing a person could indicate illness. This was first demonstrated back in 1989 when a woman’s dog detected melanoma in her skin. 

Doctors and veterinarians have noted that dogs have a significantly large olfactory epithelium. This allows dogs to see their world through their noses essentially. Therefore, your dogs might be sniffing your car vents because they smell danger or some other curiosity!

Is It Dangerous For Dogs To Sniff Or Lick Car Air Vents?

2016 Audi A6 S-line rear passenger vent
2016 Audi A6 S-line rear passenger vent

It’s not necessarily dangerous for dogs to sniff or lick car vents, especially in moderation. If they do it obsessively, it could indicate your dog has an issue either physically or psychologically. Additionally, if there are residues on the vents of toxic substances, your dog could ingest them and become sick. 

Dogs and cats are highly allergic to some ingredients found in natural and artificial air fresheners. Some of these ingredients include: 

  • Tea tree oil
  • Birchwood oil 
  • Peppermint oil
  • Ylang ylang
  • Wintergreen 
  • Camphor
  • Acetone

These are just a few of the compounds commonly found in air fresheners that can harm your furry friends. Many people use these compounds in one form or another on their car vents to keep the car fresh. 

Although they aren’t harmful in the air, they can be harmful if consumed. Your dog will likely have an allergic reaction since they rub their tongue and nose all over your vents. 

Additionally, car oil is possibly on your vents even if you don’t use air fresheners in your car. Since these vents pull heat and air from the engine, small amounts of oil may carry inside the cabin. If your dog is rubbing its nose and tongue all over the vents, it might pick up this residue. 

What Could a Dog Be Smelling in Car Vents?  

Dogs might simply smell the world around them, which causes them to sniff vents out of curiosity. They’ll typically adapt eventually and cease sniffing the vents. However, your dog might be smelling something rotting or clogging your air vents. 


Dogs can effectively locate mold, spores, and fungus. According to several studies, dogs can even smell mold before it takes root! 

This makes them a potent weapon against mold spores and fungal growth. They can usually sense the presence of harmful bacteria and mold, even in spaces that aren’t ideal for their growth. 

If your dog reacts strongly near your car vents, it might be time to clean them with an anti-microbial soap!

Rotting Vegetation

Dogs could also smell rotting vegetation in your car vents. Although their behavior might not seem overly distinctive, if you notice your vents have decreased airflow, check the ductwork! 

Check your car’s vents and filters to see if they’re blocked with decaying leaves. It’s an important part of car care and maintenance and will keep fresh air in your car cabin. 

Dead Animals or Insects 

If your dog occasionally growls at your car vents, you might have an animal trapped inside. Although this is uncommon, animals and large insects occasionally crawl inside the ductwork and die. 

This is especially true in cold regions where animals and bugs seek to escape the elements. Your dog can probably smell these creatures and might display aggressive behavior when smelling the vents. 

Should You Switch Off Car Air Vents When Your Dog Is In The Car?

There is no need to shut off the car air vents when your dog is in the car. There are ways to discourage your dog from licking and sniffing your vents. Rather than shutting off your car’s ventilation system, train your dog and clean your vents regularly. 

Dogs need proper ventilation while inside the car to prevent hyperventilating. Unfortunately, dogs don’t have sweat glands like humans. Therefore, they need more ventilation and cooler air than humans require while they’re in enclosed spaces. 

In the wild, dogs and wolves roll in the mud to cool themselves down. This is because dogs only have two types of sweat glands which aren’t effective at cooling the dog. These glands include the following: 

Apocrine glands are hormonal glands used for mating and reproduction. They can be found all over a dog’s body and in areas such as the breasts of humans. While these glands are shared between humans and dogs, they differ in their use. 

Merocrine glands are only found on a dog’s paws, which are more common in humans. These glands cool the body down and are why we sweat when we’re hot. 

The evaporation of sweat and exposure to the wind are important parts of the human cooling system, but dogs can’t do this. The wind doesn’t reach their bodies thanks to their fur, so sweat glands aren’t useless. However, since dogs are covered in fur and thus can’t vaporize sweat. 

Dogs rely on rolling in mud and water to keep cool in the summer. Therefore, since we don’t bring a mud bath with us in the car, we need to have the A/C on for our furry friends. 

Not only is it safe to have your vents on with your dog in the car, but it’s also essential. 

If you’re concerned about their health if they continue licking vents, you can try these methods to prevent this: 

  • Spray lemon juice on your car vents 
  • Spray them with water whenever they lick the vents
  • Avoid using any artificial or natural air fresheners on your car vents 
  • Bring a chew toy

Lemon juice is bitter enough to discourage animals from licking surfaces. It’s also unharmful to your dog, so it should be fine for them, yet unpleasant! 

If you suspect your dog is acting out due to stress, bring something for them to chew on in the car. You can bring a chew toy or a snack such as a bone or pig’s ear. This will be pleasant enough to keep them away from your vents! 

Finally, keep your dog away from the vents if all else fails. Keep them in the back of your vehicle, away from the vents! 


Dogs are our best friends, and we want to make them comfortable when they travel with us. While turning off the vents isn’t an option, there are several ways to treat this impulsive behavior. 

If you suspect your dog is ill or has ingested something toxic, take them to the vet immediately! The sooner they get treatment, the better they’ll be. 

Above all, discourage their curiosity by regularly cleaning and caring for your vehicle’s climate system. 


PNAS: Dog domestication and the dual dispersal of people and dogs into the Americas

PBS: The Evolution of the Dog

Nerdfighteria Wiki: SciShow: Dogs Love the Smell of Stress

Concord Veterinary Hospital: Do dogs have bad eyesight?

Cat Protection: Cats are mid sighted

The Dodo: Dogs Love To Smell, So Try To Be Patient

American Kennel Club: Can Dogs Taste?

American Kennel Club: Teach Your Dog to Ride in the Car: Prevent Anxiety and Motion Sickness

PetMD: Why Do Dogs Lick Everything?

American Kennel Club: Why Is My Dog Licking Me?

American Kennel Club: Why Does My Dog Sniff Everything?

Nature: The dogs learning to sniff out disease

Mayo Clinic: Melanoma

Science Daily: New details in how sense of smell develops

PetMD: How Air Fresheners Can Affect Your Pet’s Health

Healthline: How to Use Camphor Safely: Benefits and Precautions

PUB C HEM: Acetone

Bio Design Wellness: Mold Exposure

Heads up for Tails: Why It’s Essential to Keep Your Dog Cool in the Car

American Kennel Club: Do Dogs Sweat?

Love Your Dog: Why Do Dogs Love Mud So Much? Here’s 6 Reasons!

Wikipedia: Merocrine

Cancer: apocrine gland

Houston Methodist: How Sweat Works: Why We Sweat When We’re Hot, as Well as When We’re Not