I get into huge discussions with horse people about shaving the hairs around the horse's mouth. Some people like the clean cut look. Other people believe the hairs are for a reason. My horses have been called hippie horses, so you can tell what side of the discussion I take ;)

I think it is just like human hair, you know its there for a reason (for a catchall to avoid bad/harmful things getting into places). However, I guess it depends on what you have your horse for (personal, shows, etc.)

I think it depends on the style of riding that determines if you shave. I was in English jumping and it was mandatory that you shave your horse. Also you had to braid the mane or people would talk. They also shave inside of the ear to get that clean look.

I've shaved Pumpkin if I have a hoity toity show to go to and its pretty much shave or don't place. Otherwise I let him be the hairy beastie he is. If you shaved off a cat's whiskers it would walk into things until it adjusted. Horses aren't that dependent on their whiskers, but I'm not about to shave down my fuzzy guy just because people think it looks better.