Dogs depend on their noses for more than just sniffing out their supper. With a few deep breaths, dogs can be trained to detect bombs and drugs and recognize the unique scent signatures of low blood sugar, cancer, and even the coronavirus.
Their keen sense of smell can be attributed to the 220 million olfactory receptors in their nasal cavities, allowing dogs to smell as much as 10,000 to 100,000 times better than their owners (1).
“We can smell cookies baking in the oven; dogs can smell the individual ingredients,” says Dr. Jessica Romine, a veterinarian and internal medicine specialist with BluePearl Veterinary Partners in Southfield, Michigan.
How Good Is a Dog’s Sense of Smell?
Your dog’s nose is filled with layers of twisted cartilage covered in a specialized tissue that provides a huge amount of surface area devoted to capturing smells, Romine says. When a dog sniffs, his nostrils open up and direct the scent toward these structures.
Dogs also have a larger area of the brain that analyzes odors, which allows them to devote more of their brain power to detect and process different scents.
Their powerful sense of smell allows them to track animals, find food, or locate their owners. Dogs also use “scent marking” to communicate with other animals; through scent, dogs communicate sex, age, health status, and even mood, Romine explains.
“Their scent is like a signature, it’s unique to each dog,” she says. “For dogs, scent marking is the equivalent to reading their text messages.”
Since dogs depend on their noses to explore the world, the skin is tough, allowing them to put their noses to the ground to follow a scent without causing skin abrasions or other damage, Romine adds.
Do Some Breeds Have a Better Sense of Smell Than Others?
Dog breeds such as Basset Hounds, Bloodhounds, Beagles, German Shepherds, English Springer Spaniels, and Pointers are often regarded as the top scent tracking dogs, but there is nothing special about the noses on these “super smellers.” Instead, Dr. Gary Dattner, a veterinarian and chief medical officer for Veterinary Care Group in New York, cites selective breeding for their heightened senses.
“The breeds were developed over long periods to develop their sense of smell,” he explains.
Why Is My Dog’s Nose Wet (or Dry)?
Dogs often have wet noses. The moist texture is due to a combination of sweat—dogs release some of their heat through their noses—and mucus glands and tear ducts inside their noses that produce clear fluid that helps them cool off through evaporation, Romine explains. Fever or dehydration could cause their noses to become dry.
Brachycephalic breeds or breeds with short noses, such as Bulldogs and Pugs, have more trouble licking their noses, which could make them prone to having drier noses.
“If there are no other symptoms, [a dry nose] is likely nothing to worry about,” Romine adds.
Why Do Dogs Lick Their Noses?
Dogs lick their noses to transfer the scent particles from the mucus on their noses into their mouths where there is an olfactory gland that enhances their sense of smell, Dattner says. This automatic reaction could get dogs into trouble.“Dogs have no inhibitions about where they stick their noses,” Romine says. “They will go anywhere the scent leads them.”
Dogs that lick their noses after sniffing feces or dirt are at increased risk of being exposed to intestinal parasites, such as roundworms, hookworms, and whipworms. That’s because dogs can ingest parasite eggs if the feces or dirt is contaminated. Dogs can also contract certain worms from nosing around and eating infected small animals, such as squirrels or rodents.
Giving dogs year-round parasite protection, like Interceptor® Plus (milbemycin oxime/praziquantel), can help keep them healthy—even when their noses get them into trouble.
Why Do Dog Noses Turn Pink?
While black noses are most common, some dogs also have pink or lighter colored noses. The lighter color might be a natural difference in pigment. Although dogs with light noses can get sunburned, Romine does not recommend applying sunscreen because dogs will lick their noses and ingest the chemicals in the sunscreen.
A condition called “snow nose” or “winter nose” can also cause a dog’s nose to change color from dark to light. The condition is more common in winter or cold climates. While the cause of this change in pigmentation is unknown, it is not harmful.
Why Is My Dog’s Nose Running?
Dogs, like humans, can get respiratory infections that make their noses run. A running nose can limit their sense of smell. Nasal cancers, infections, autoimmune diseases, and even aging can also affect a dog’s sense of smell.
Dattner notes that when a dog loses his sense of smell, it shrinks his world.
“People don’t really understand how sensitive a dog’s sense of smell can be,” he says. “Scent is their most important sense.”
When it comes to a dog’s remarkable sense of smell, there’s certainly more than meets the nose.
Interceptor Plus prevents heartworm disease and treats and controls adult roundworm, hookworm, whipworm, and tapeworm infections in dogs and puppies 6 weeks or older and 2 pounds or greater.
Interceptor Plus Important Safety Information
Treatment with fewer than 6 monthly doses after the last exposure to mosquitoes may not provide complete heartworm prevention. Prior to administration of Interceptor Plus, dogs should be tested for existing heartworm infections. The safety of Interceptor Plus has not been evaluated in dogs used for breeding or in lactating females. The following adverse reactions have been reported in dogs after administration of milbemycin oxime or praziquantel: vomiting, diarrhea, decreased activity, incoordination, weight loss, convulsions, weakness, and salivation. For complete safety information, please see Interceptor Plus product label or ask your veterinarian.
Disclaimer: The author received compensation from Elanco US Inc., the maker of Interceptor Plus, for her services in writing this article.
- Jenkins EK, DeChant MT, Perry EB. When the Nose Doesn’t Know: Canine Olfactory Function Associated With Health, Management, and Potential Links to Microbiota. Front Vet Sci. 2018;5:56. Published 2018 Mar 29. doi:10.3389/fvets.2018.00056
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