For some dogs, a trip to the groomer (or even a trip to your kitchen counter for a good brushing) can be traumatic.  This could be because grooming involves touching dogs in places they are not used to being handled, such as their feet, tail, groin, etc. A simple way to help your dog get used to such touches is to simulate the grooming experience a few times per week while playing with them or simply while petting them.  For example, if you are playing with your dog, you could manipulate their paws to calm them down. You can also run your hand down their tail. When doing this practice for actual grooming, make sure speak in a calming tone, and make sure to praise your pup often.  The goal is to teach your dog to associate a positive response to being touched.