Ways to treat car sickness in dogs

A client on Facebook recently asked this question:

Received newsletter about CERENIA relieving car sickness in dogs. Side effect is drooling which IS my dog's symptom of car sickness. Wonder if this med would work for her drooling/car sickness AND if she does have the side effect of drooling, how would I know if it is a side effect or just her symptom of car sickness? Lastly, is this med safe to use in pregnancy?

Cerenia is a fairly new, highly effective medication for the treatment of motion sickness. However, it has not been evaluated for use in pregnant or breeding dogs. As far as the drooling side effect, the only suggestion from Dr. Combs would be to try it and see if it happens. The other option would be to try Benadryl (diphenhydramine), please consult with your veterinarian regarding doses.

For more information regarding Cerenia, here is Pfizer's official page. This page also includes tips for traveling with your pet, and other useful links.