Pet your dog with “stuff and things”. 
Grab whatever is on the table and pet your dog with it. A Kleenex box, a cup, a coaster, ect. AND touch your dog often and EVERYWHERE. This will make it where you or the vet or the pet sitter or the groomer can always check on your dog, doesn’t have to worry about scaring or eliciting a reaction from your dog and can accomplish their job safely.
At the groomers your dog will experience someone touching them everywhere. Groomers will also be putting things on, near and around your dog that might be “odd” to a dog. (Scissors, clippers, dremel, spraying water, high velocity dryer, brushes, ect.) 
We want your dog to remain calm and safe. Instead of thinking “oh! What is that!” We want them to think “ya, my parents touches me with weird things all the time, this is fine.”
By Michelle McCauley - The Mindful Groom @mybestfriendsmunchies