I am a groomer and I hear people often say that their dog is afraid. Sometimes it is for the simple reason that they are left there by their owners. It probably seems like a very long time to them until they are reunited with their family. Some don't like their nails done, some are allowed to get matted and the brushing out hurts them, some don't like the sounds or being around other dogs. some don't like to be wet. Some don't act like anything in the whole procedure bothers them in the least, but the owners still say the dog hates it. Truth is, most owners do not like to leave their pet and the pet picks up on this apprehension and gets scared.