Most dogs are hairy things. Whether their fur is long or short, their bodies are mostly covered all over in hair of some sort. But separate from the fluff and the fur, your pup has long, coarse hairs sticking out of his muzzle and above his eyes.
Dogs might not be as well-known for their whiskers as cats, but these distinctive features play an important role in your dog's daily life.
What are whiskers?
Whiskers are a type of coarse hair called vibrissae found in nearly all living mammals. They were also likely to have been present in early mammal ancestors.
Cats usually have 12 whiskers in neat rows on each side of their face, for a total of two dozen per kitty. Dog whiskers aren't quite so uniform.
They vary from dog to dog, says canine expert Stanley Coren, Ph.D., of Psychology Today. They're typically found on both sides of their muzzles with a few sticking out above their eyes. Some dogs also have whiskers pointing down from above their upper lip, on their cheeks or beneath their chin.
The purpose of dog whiskers
Although whiskers might just look like stiffer, coarser hair, they have a much different job to do. The follicles at the base of each whisker are filled with nerve fibers so that even the slightest touch will transmit messages to the dog's brain.
The area around a dog's muzzle and mouth are particularly rich in Merkel cells (MCs), a special type of cell found right below the epidermis, the top layer of skin. Merkel cells are skin receptors closely linked with nerve terminals, making these whisker-heavy parts of the face key for sensations, according to a study in Research in Veterinary Science.
These special facial hairs play many roles, according to research published in Veterinary Research Communications. They can play a key role in helping a dog monitor his environment by picking up changes in wind direction or water currents.
Coren points out that the whiskers above the eye are situated so that when something disrupts the airflow or some object gets in the way, causing the hair to bend, there's a reflexive blink in response to protect the eye from a possible impact.
You can see this in action by lightly brushing the whiskers above your dog's eyes. Instinctively, his eye should close.
Whiskers also might assist in locating food, dispersing pheromones, and maintaining an upright head position while swimming.
Because dogs are more farsighted than nearsighted, whiskers can assist with up-close vision. They can help assess whether they're brushing against walls or whether they can fit through a tight space. Whiskers usually grow out to the width of a dog's body so if the whiskers hit a surface, the dog instinctively knows he won't be able to squeeze through.
Whiskers and communication
Besides keeping a dog from bumping into things, whiskers also can help avoid skirmishes and bad relationships.
We're used to looking to a dog's tail or maybe his ears to see how he is feeling. But whiskers can also convey information about canine emotions, according to LiveScience.
If a dog feels threatened, he will automatically flare his whiskers and then point them reflexively in a forward direction. This could indicate that whiskers are a key element of defense in tense situations with predators and other dogs, some researchers believe.
But whiskers don't just move during tense situations, says VCA Hospitals.
"When a dog is resting, the whiskers take a break. But when a dog is active, so are they! A happy or curious dog will elevate the whiskers above his eyes giving him that cute, wide-eyed appearance we love."
Do all dogs have whiskers?
The majority of dogs have whisker in some form or another. Some have them in long, thick bunches while others have just a smattering of coarse hairs.
There doesn't seem to be any difference between most breeds, except for hairless breeds of dogs and cats, which may have few whiskers or none at all, Dr. Jessica Vogelsang, DVM, and author of "All Dogs Go to Kevin," tells PetMD.
Can you cut a dog's whiskers?
Some people — especially those who show their dogs in competitions — choose to trim whiskers because they think it makes their dogs look neater.
Pulling or plucking on the whiskers would be painful for a dog. It wouldn't hurt to cut them because whiskers don't have pain receptors, but many veterinarians and researchers say it's not a good idea.
Anecdotal evidence suggests that trimming whiskers can lead to confusion and issues with spatial awareness. When petting your dog, in fact, be sure to only touch pet whiskers gently along the grain, says VCA Hospitals. As you can see in the video above, even very tolerant dogs don't like anyone messing with their whiskers, even if it's gentle.
Say canine expert Coren, "Although your dog's whiskers might make his face look untidy, you should not let your groomer trim or cut them since by so doing you are actually effectively removing these valuable aids to the dog's visual system."