Dogs whiskers are primarily for the use of gauging space. If the whiskers touch the hole, the hole is to small to get into. We all know that doesn't always hold true. We see dogs chase rabbits into tiny holes, we see dogs dig holes. Some breed of dogs don't even have noticeable whiskers. Show dogs are routinely clean shaven. No ill side effects. There is no evidence that a dog is abused or losses any of it's senses if it's whiskers are cut. Same thing with a dogs tail.
Umm not sure about that but I am sure of this. Believe it or not If you cut your dogs whiskers off they will be off-balanced. Their whiskers help them balance and track smells. It's a terrible thing to do to a dog. Basically it's like blocking one nostril and one eye for humans. Not cool!