Why Do Dogs Have Whiskers?

If you live with a dog, you’ve probably noticed your dog’s whiskers—stiff, coarse hairs that stick out from the fur around the nose and eyebrows. You may particularly notice them when your dog is expressing emotion or communicating a desire to you (like begging for that last bite of food on your plate). So, why do dogs have whiskers? They are part of an important sensory system that helps dogs navigate their environment. 

What Are Dog Whiskers?

Whiskers are sensory hairs that are also called vibrassae, tactile hairs, or sinus hairs. They differ in structure from the hairs that make up your dog’s fur, not only in appearance, thickness, and stiffness, but also in how they are connected to your dog’s body and brain. Whiskers are only located on dogs’ faces and can be found above the eyes, around the nose, under the chin, and on the cheeks. Since dogs use their faces and noses to glean all sorts of information about their world, it makes sense that whiskers would develop in these areas to provide extra sensory input.

While a dog’s fur is designed to protect the skin and regulate body temperature, whiskers are uniquely designed to pick up on the slightest touch and transmit that sensation to your dog’s brain. These special tactile hairs are so sensitive that they can even sense slight changes in air movement around a dog’s head and help your dog estimate the size and shape of, and distance to, surrounding objects. 

Anatomy of Dog Whiskers

The unique anatomy of whiskers, compared to other types of hair, is responsible for their sensory function. Fur grows from hair follicles, which are small pockets of cells and connective tissue in your dog’s skin. The follicles surrounding whiskers are much bigger, with a large blood supply and many nerves. This blood supply is called a blood sinus (hence the name sinus hairs). When the whisker encounters even a very slight touch or pressure change, it transfers this pressure to the blood sinus, where it’s amplified and transmitted to the brain via sensory nerves. This results in a highly responsive system. 

There’s also a difference in the type of muscles that move whiskers. You may have seen your dog’s fur stand up along the back when scared or startled. This is an involuntary reaction caused by smooth muscle movements under the skin—similar to when people get goosebumps. In contrast, whiskers are connected to striated muscle, the type of muscle that’s involved in voluntary movements. Dogs can control whisker movements, moving and extending them as needed.

Whiskers develop very early in the embryonic stage of dogs and appear before any other type of hair. Because of this, whiskers may perform important functions in newborn puppies, who cannot see for the first ten days of life, like finding their mother and locating nipples for nursing.

What Are Dog Whiskers For?

Whiskers help dogs perform a variety of vital functions, including:

• Finding their way in the dark
• Navigating through narrow or tight spaces 
• Distinguishing objects up close where eyesight is less reliable 
• Locating food and water 
• Determining threats in the environment 
• Expressing interest or curiosity 
• Detecting wind direction for locating smells
• Picking up small objects with the mouth

Whiskers also protect the eyes and face from injuries by triggering reflex reactions like blinking when something touches the whiskers above the eyes. Whiskers let a dog know ahead of time when a sharp stick or branch is near the face, allowing the dog to avoid potential injury.

For blind dogs or senior dogs experiencing visual impairment as a result of aging, whiskers are crucial for these dogs to continue to navigate their homes in comfort.

Dangers of Removing Dog Whiskers

Whiskers may not seem like they're doing much to the naked eye, but they are essential for dogs to avoid danger and safely move through their environment. Dogs who have had their whiskers removed are more prone to injuries, and sightless dogs without whiskers will bump into walls and corners. Whiskers should never be removed because of the important sensory function they perform in dogs, unless there is a medical reason to do so, like treatment of a wound or an abscess. 

While the whisker itself does not feel pain when cut because there are no nerves in the actual hair, dogs will still feel discomfort when their whiskers are cut or shaved. Dogs with trimmed whiskers have difficulty fetching balls and have been observed dropping the ball immediately after picking it up–a possible indication of discomfort due to missing or shortened whiskers. 

Dogs may occasionally damage or shed a whisker here and there, but as long as the follicle beneath the skin is not damaged, the whisker will grow back. 

Dogs rely on whiskers to let them know about their surroundings, and it’s important to never deprive them of that critical sensory organ. And the next time you see your dog sniffing or exploring, you’ll know about the incredible interplay of senses that give your dog an accurate picture of the world.