How Deep Is a Dog Whisker?

Dog whiskers aren't just hairs. They're thicker and more deeply rooted, and they serve a different function than the rest of your dog's coat. In general, they're rooted three times as deep and are surrounded by more nerve cells, which is why whiskers are so sensitive.

  1. Coat and Whiskers

    • Your canine friend's coat and whiskers may look alike, but they serve different, specialized functions and are rooted according to those purposes. Both hair and whiskers grow through follicles in the epidermis and are made of keratin -- the same tough, fibrous protein that comprises their nails -- but that's where the similarity ends. Dogs have one longer, coarser primary hair and multiple shorter, fuzzier hairs per follicle. Those follicles extend a couple of millimeters into the dermis. Whiskers are twice as thick and root much deeper than other hairs, although they're still well within the dermis.

    The Root of the Issue

    • The depth of a dog's whisker varies by skin thickness. The average dog's skin varies between 0.5 millimeter and 5.0 millimeters, according to Mueller and Kirk's Small Animal Dermatology. Whiskers are located above a dogs' eyes, along their muzzles and under their jaw line, all among the thickest-skinned areas on a dog, regardless of breed. As a general rule, a dog's whiskers are rooted three times deeper than the rest of his hairs. That's a ratio, not an exact length; dog hair and whisker length varies among and within breeds. If a dog's hair is rooted, say, 2 millimeters deep, the nearby whisker would likely be 6 millimeters deep. The dermis, home to hairs and whiskers, also contains sebaceous glands, blood vessels and nerve endings. The last two are particularly important when it comes to dog whiskers.

    For Whiskers' Sake

    • Your dog's whiskers are called vibrissae. They vibrate and create tactile sensations on account of densely packed blood and nerve cells. Whiskers are kind of like radar -- they let your dog know what's around them, even in low light -- They function via touch, like your fingertips. Many dogs have dark whisker mounds like beauty marks on either side of their faces. Each nerve-dense mound has compound follicles from which sprout many whiskers. Your dog's whiskers can grow at strange, haphazard angles, and sometimes even split when they're damaged. Don't worry, though: They'll grow out and back on their own sans human intervention.

    Whisker Cutting and Other Issues

    • Don't cut, trim or remove your dogs' whiskers, even if they're damaged. Because whiskers help them orient dogs to their worlds, a sudden change in whisker length can disorient and confuse them. Moreover, whiskers are tied to more blood vessels than standard hairs, so they're also more likely to bleed -- and profusely at that. Dogs grow, lose and regrow whiskers by rotation throughout their lives. Sometimes trauma or disease can interfere and lead to acute whisker loss. There's a long list of possible issues, most of which would also affect your dog's coat. If you think something's wrong with your dog's whiskers, contact a vet.