Whiskers, or vibrissae, are found in all mammals apart from monotremes (the bizarre duck-billed platypus and echidna) and humans. They have a huge array of functions, serving as a sensory organ and allowing the animal to take in information about its surroundings. Keep reading to learn more.
Animal senses
Arguably, animals have far more sense than humans in all definitions of the word, and in their ability to observe the world around them they are leagues ahead of us!
Some animals have sensory adaptations that we can’t even begin to relate to, such as echolocation in bats and dolphins, the ability of bees to see ultraviolet, and electrical field senses in fish. With these extra senses, animals perceive the world differently to us, with sensory abilities far exceeding our own.
The science bit!
Vibrissae are found on various parts of the body, even the forelegs and feet in some animals, but in dogs they are located around their muzzle, and above their eyes. They are different to the fur on the rest of the body in that the hairs are thicker and more rigid, more deeply rooted, and are in follicles surrounded by nerves and sensory cells. Whiskers act as levers on these nerves, which are connected to the spatial processing area of the brain.
What are they used for?
The answer is lots of things we know about, and probably some we don’t. Whiskers are a tactile, sensory device used to gain knowledge about an animals’ surroundings. They can help to detect the distance, location, size, shape and texture of objects or other animals, assist in finding prey and avoiding injury, and are used in facial expression and communication. They are sensitive enough to pick up air currents and changes in climatic conditions, which could explain why some dogs, who are afraid of storms, start acting strangely before the first rumble of thunder.
How important are they in dogs?
It is surprising to learn that in dogs, vibrissae are connected to the largest of twelve pairs of cranial nerves; larger than those dealing with other senses such as smell, hearing and sight.
Nature tends to be very sensible on the whole, and more resources are given to the organs or biological systems which are the most useful. In dogs, a large amount of the sensory cerebral cortex (the part of the brain which deals with information coming from the senses) is taken up by the face. This means that this area of the body is incredibly important to dogs in terms of taking in information about the world around them.
What happens if whiskers are removed?
Unfortunately, it is common practice for show dogs to have their whiskers trimmed for purely cosmetic reasons, to supposedly give them an edge in competition. As humans, with our basic five senses, it is difficult for us to appreciate what it would be like to be able to perceive the world any differently, so the sensory deprivation these dogs are subjected to is beyond our level of understanding.
Scientific research on the effects of vibrissae removal in dogs is limited (which, morally, is a blessing!), however, studies on rats showed that animals without whiskers displayed less exploratory behavior and more stress responses in new environments, and it affected their depth perception, swimming capability, balance and ability to defend themselves in a fight. In cats, it was found that with blindfolding alone, the cats could still catch a mouse, but with blindfolding and without whiskers they could not find it, or if they did, they could not locate the right part of the neck to catch it by.
Anecdotally, owners of ex-show dogs which were also used for hunting, reported that their animals sometimes got facial injuries while hunting, but the injuries stopped occurring once their trimmed whiskers had grown back. An owner of a blind dog also stated that they couldn’t work out why their pet suddenly started bumping into furniture, until they found out that their groomer had trimmed its whiskers without them knowing. Once the whiskers grew back, the dog was once again able to navigate its way around the house without a problem.
So, it appears that whiskers are an essential tool in a dog’s repertoire, and, without them, they find it much harder to function in their surroundings.