Inuya

Tosh had a haircut and realized just how good it felt to have short trimmed hair in this summer heat, so he agreed to take the dogs to Inuya for their second clipping this summer. The dogs readily jumped out of the car and headed  happily in for their grooming session, and I was quite relieved because that means we can continue using Inuya - they really do a great job with the special setter cut, the dogs come out looking picture perfect. I asked the owner not to cut their whiskers, called vibrissae, because I walk the dogs early in the morning when it's still dark, and according to Stanley Coren, they need the whiskers to avoid bumping into things, a bit like a blind person's cane:

"Dogs have a set of stiff hairs protruding from the sides of their muzzles. Popularly called whiskers, these are technically called vibrissae. Vibrissae are sophisticated devices that help the dog feel its way through the world. They are quite different from most other hairs on the dog's body, more rigid and embedded more deeply into the skin. At the base of each vibrissa is a high concentration of touch sensitive neurons.

Of those areas of a dog's brain that register touch information, nearly 40 percent of it is dedicated to the face, with a large amount of that dedicated to the upper jaw where the vibrissae are located. You can actually map each individual vibrissa to a specific location in the dog's brain, suggesting that great importance is assigned to information from these structures.

The vibrissae serve as an early warning device that something is near the face, and thus prevent colliding with walls and objects, and keep approaching objects from damaging the dog's face and eyes. You can tap gently on the vibrissae of a dog, and the eye will blink protectively, and the dog will tend to turn its head away.

The vibrissae also seem to be involved in the location and perhaps in the recognition of objects themselves, much the way that a blind person uses a cane. First, the little muscles that control the vibrissae direct them somewhat forward when the dog is approaching an object. Next they actively "whisk," or vibrate slightly while the dog swings his head to drag these hairs across surfaces. Whisking gives information about the shape and roughness of surfaces near his head. Since the dog's eyes can't focus very well on close objects, and his muzzle blocks his line of sight when he is looking at things near his mouth, the information from the forward and downward pointed vibrissae appears to help him locate, identify, and pick up small objects with his mouth.

Many dog fanciers are unaware of the importance of vibrissae. Unfortunately, amputating vibrissae is both uncomfortable and stressful for dogs, and it reduces their ability to perceive their close surroundings fully.

Specifically, dogs whose vibrissae have been removed seem more uncertain in dim light. They actually move more slowly, because they are not getting the information to tell them where things are that they might bump into. These special hairs are so sensitive that they also register slight changes in air currents. As a dog approaches an object like a wall, some of the air that he stirs up by moving bounces back from surfaces, bending the vibrissae slightly, which is enough to inform him that something is near well before he touches it. "

Source: http://www.psychologytoday.com/blog/canine-corner/201109/why-do-dogs-have-whiskers

I took the liberty of editing the original text down to make it an easier read for some of my Japanese blog followers: I recommend reading the original well-written story. Meanwhile my son found the pertinent info obviously translated from this original text in a Japanese search.