It depends why he's getting car sick. Some dogs have anxiety because they mostly have only gone to vet visits which can be painful. So they have learned to be anxious. Other dogs have anxiety because they actually get nauseous from the motion of the car. That would be more of a physiological problem with the inner ear, rather than a psychological problem of anxiety. If it’s due to nausea and motion, then I would try a drug meant to help with motion sickness. Also, allowing the dog to see outside, rather than lying down in a bed can remarkably improve motion sickness. If’s it’s due to anxiety, than a calming pill could help and also be sure and take him to lots of fun places between vet visits. I haven’t tried the pill you mention, I have tried Comfort Calm and it really helped Ralphie when he was having panic attacks. The main ingredient of Richard's Organics Pet Calm is Valerian and that is said to have a calming effect. The main ingediant of Comfort Calm is Tryptophan an amino acid found in many foods and also has a calming effect. Both sound safe.
Here’s a link to the Comfort Calm.
Vet's Best Comfort Calm (30 Chewable Tablets)
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