Daily CBD May Ease Some Signs of Car-Travel Stress in Dogs, but Benefits Were Limited

For some dogs, a car ride can mean whining, lip licking, restlessness and other signs of distress. A 2024 study found that daily cannabidiol (CBD) administration reduced some physiological and behavioral indicators of that stress—but the effect was modest and did not persist across every test.

The study published in the Journal of Animal Science was conducted by researchers at the Waltham Petcare Science Institute in the United Kingdom. It examined whether a THC-free CBD distillate could affect dogs’ responses to repeated car travel over six months. The research was funded by Mars Petcare.

Twenty healthy adult dogs—Labradors, Beagles and Norfolk Terriers—were randomly assigned to receive either CBD or a placebo. The dogs were given a targeted dose of 4 milligrams of CBD per kilogram of body weight each day. About two hours later, they underwent a standardized 10-minute car journey. Testing took place at the beginning of the study and again at weeks 8, 16 and 24.

Researchers assessed stress using several measures, including serum cortisol, heart rate, heart-rate variability, activity levels and behaviors such as whining, yawning and lip licking. The car journeys produced changes in multiple measures, indicating that the testing situation was stressful for these dogs.

Dogs receiving CBD had a significantly smaller rise in cortisol than dogs receiving the placebo during the first three car-travel tests. By week 24, however, that difference was no longer statistically significant. The placebo group’s cortisol response appeared to decline over time, suggesting that the dogs may have become somewhat accustomed to the journeys. The CBD group’s post-test cortisol levels remained comparatively stable rather than showing the same apparent habituation.

The results do not show that CBD eliminated travel anxiety or that it worked equally well on every measure. The researchers described the effect as potentially mild and noted that the benefits varied depending on the behavior or physiological response being examined. The study also cannot establish whether the same results would occur in household pets with severe travel anxiety.

That limitation is important. The dogs lived in a research facility, were healthy, represented only three breeds and were not selected from homes because of diagnosed travel-related anxiety. The study also used a specific THC-free CBD formulation and dose, so its findings should not automatically be applied to every oil, treat or supplement sold for dogs.

A related 2023 study by the same research group examined a single 4 mg/kg dose given two hours before a car journey. It found lower cortisol and improvements in some behavioral ratings compared with placebo, but it also emphasized that CBD’s effects differed across measurements and that further research was needed.

CBD should therefore be viewed as a possible adjunct—not a proven stand-alone treatment—for canine travel stress. Gradual desensitization, short positive training trips, secure vehicle restraint and treatment of motion sickness may also be relevant, depending on the dog’s symptoms. A veterinarian can help determine whether anxiety, nausea, pain or another medical issue is contributing to the problem.

Pet owners should also be cautious about product quality and dosing. The U.S. Food and Drug Administration says it has not approved cannabis products for use in animals and cannot ensure that marketed products are safe or effective. It recommends discussing CBD and other treatment options with a veterinarian.