Yes, Rescue Remedy is a Bach Flower homeopathic supplement that can help with anxiety. Some herbs that are also effective are valerian, hops, skullcap, chamomile. There are some products formulated just for dogs like Only Natural pet stress soother. Consult with an herbalist in your area and have a 'concoction' made that is suitable for your pet.
I have found behavioral modification helpful in getting your pet 'used to travel' and the groomers.
Small short trips in the cars, can help desensitize a pet to the car. Do this on an empty stomach and slowly a block at a time. Once the dog gets used to being in the car, VISIT the groomer, when nothing is going on . Then leave, quietly and do this as many times as you can so the dog doesn't associate anything negative with the events.
If the dog is unusually anxious at the groomers, be sure to check out the staff, and how they handle the dogs. You could be shocked, even with the best of groomers. Some of the procedures they use or crates they are kept in would scare the toughest of puppy clients. If you are not allowed to 'visit' the grooming area, I would look for another groomer.
My poodle came back from my groomer with nicks all over and looked like she was stressed out. After inspection of the facilities, I was shocked to know that she was kept in a crate OUTSIDE, in hot weather, waiting for her turn.
Anxiety is something that we can teach our dogs to cope with and yet using a 'calmative formula' like Rescue Remedy can help There are other anxiety remedies too from Homeopet that can help too. I am most familiar with Dr. Bach's remedies.