Study review: A single dose of cannabidiol (CBD) positively influences measures of stress in dogs during separation and car travel

Date: 22 February 2023
Publication: Frontiers in Veterinary Science
Authors: Alysia Hunt, Hannah Flint, Darren Logan, Tammie Kin
Purpose: to study the effectiveness of CBD for anxious dogs
Using: a single 4 mg/kg dose of broad-spectrum CBD oil for dogs
Full study:

What happened?

  • Researchers gave dogs a medium dose of broad-spectrum CBD oil, and other dogs a placebo oil containing no CBD.
  • They then observed the dogs’ stress hormones, heart rates, and overall behavior while they were left alone in a room for 45 minutes, and taken on a 10-minute car ride.
  • Dogs who were given CBD oil showed fewer stress behaviors, seemed less agitated, and had bigger reductions in the stress hormone cortisol.
A single dose of cannabidiol (CBD) positively influences measures of stress in dogs during separation and car travel study - testing timeline

(image source:

Figure 1. Diagram illustrating test day timeline, including CBD/placebo administration, baseline recording, baseline sample collection, test session, and post-test sample collection.

What were the results?

Based on factors like stress hormone levels and stress-related behaviors, the researchers found that CBD did “significantly” reduce canine stress, especially during car journeys.

Abstract summarized:

Two things that stress many dogs out are separation from their owners and car rides.

There are many owner strategies for managing separation anxiety and vehicle phobias, from crate training to medications – but there’s no single agreed-upon solution.

In recent years, CBD oil for dogs has grown in popularity as an effective way to reduce canine anxiety. There’s a bunch of clinical evidence suggesting that CBD alleviates anxiety in humans, but does it actually work for pups?

This study, published in February 2023 in Frontiers in Veterinary Science by researchers from Waltham Petcare Science Institute in the UK, tested the effects of CBD for anxious dogs who were left alone for 45 minutes and in a crate during ten-minute car rides.

A single dose of cannabidiol (CBD) positively influences measures of stress in dogs during separation and car travel study - two dogs during testing

(image source:
Figure 2. (A) Separation test room setup showing position of vet bedding (center, with a dog on top), then clockwise from top: cardboard box, water bowl, dog bed, crate, and toys. (B) Car test setup showing metal crate secured in rear of the car. Video cameras were positioned at the front and rear of the crate.

Researchers gave the anxious dogs a single 4 mg/kg dose of broad-spectrum CBD oil – a medium-quality form of pet CBD oil that contains fewer natural active compounds than the oils we recommend.

The researchers observed the dogs by recording things like stress hormones and heart rate, as well as their behavior, such as how much they whined, paced, panted, and acted in an agitated manner. They also carried out the same test on a placebo group who were given dummy oil without any CBD.

When comparing the dogs who were given CBD to the placebo group, the researchers found that dogs who’d been given CBD showed lower levels of the stress hormone cortisol compared to baseline, and were judged to be more calm and relaxed by trained observers.

Introduction summarized:

Owners need their dogs to fit into their lifestyles, and that can cause unavoidable stress. Two parts of a normal routine that make lots of dogs anxious are being left alone for short periods and going on car journeys.

While stress during these times might be unavoidable, it can be harmful to dogs’ long-term physical and emotional health.

Some vets recommend giving anxious dogs drugs like clomipramine and fluoxetine, but these can come with nasty side effects and require weeks of daily doses before effects are seen.

Another option is pheromone-based remedies, but these don’t seem to work for all dogs.

CBD is another treatment for canine anxiety that’s becoming increasingly popular. Studies suggest that CBD can reduce anxiety in humans, and vets have found that it’s safe for dogs to use – both for long periods (4 mg/kg per day for six months) and in high doses (20 mg/kg).

This study looks at how being separated from owners and car rides causes stress in dogs, and if CBD can help to reduce that separation anxiety and stress.

Materials and methods summarized:

Researchers gathered 40 dogs of various breeds and ages. There were Labradors, Beagles, and Norfolk Terriers, aged between one and nine years old.

The dogs were evenly split into test and control groups.

Each dog was equipped with a special, pet-safe chest monitor and smart collar, which together recorded biological signs of stress.

The study used broad-spectrum CBD oil capsules made from Canadian hemp and sunflower oil. The product contained CBD, trace amounts of CBD-V, and no other active cannabis compounds.

The placebo group received the same product without any CBD or CBD-V.

To test the effects of CBD on dogs experiencing separation anxiety, dogs were left in a familiar room for 45 minutes.

As for testing CBD on dogs during car rides, dogs were put into a crate and driven around for 10 minutes.

Dogs’ stress levels were observed by monitoring their serum cortisol, immunoglobulin A, and glucose levels, as well as their heart rate, heart rate variability, distance traveled, body position, and activity levels.


image source:
Table 2. Ethogram used to measure dog behavior during the separation and car travel tests.

In addition, dogs’ behavior was judged by trained observers according to a multi-factor Qualitative Behavior Assessment (QBA) that included over a dozen parameters. Those parameters included whining, barking, pacing, panting, howling, digging, vomiting, yawning, licking, and attempting to escape.

To calculate the effects of CBD on canine stress, all of these measures were fed into statistical models called linear mixed effect models.

Results summarized:

Dogs in both the CBD and placebo groups experienced heightened levels of stress hormones during the car ride, but not when left alone in a room.

Dogs in the CBD group then showed reduced levels of stress hormones after the test compared to the placebo group.

IgA and glucose levels were similar for both groups. So were heart rate and HRV.

The trained observers judging the dogs’ behavior did find some differences between the groups – although again, the differences weren’t huge.

All the dogs became more anxious and stressed when left alone and driven in the car.

But, dogs in the placebo group were less “comfortable” and “relaxed” compared to the baseline in the car, and more “nervous,” “sad,” and “tense” compared to the baseline when left in the room.

Interestingly, researchers found that dogs in the CBD group also became “less comfortable and more restless during the separation test compared to baseline.” Overall, they thought that dogs given CBD were less “uncomfortable, stressed, and nervous,” and more “calm and comfortable.”

Discussion summarized:

Being left alone is stressful for dogs. But giving them a dose of CBD can make them less stressed, sad, tense, and uncomfortable.

During travel, CBD can make dogs less “sad” and more relaxed, even if it doesn’t completely remove the stress of car journeys.

However, there were some limitations to this study. Only a single, medium dose of CBD was given to the dogs, around two hours before the stressful event. That might not be enough CBD – or enough time for it to take effect.

Also, there were only three dog breeds in the study, and all the dogs were “healthy” and not diagnosed with extreme separation anxiety or travel phobia.

For more information on pet-friendly products, see our recommended CBD oils for dogs, including a comprehensive guide with everything you need to know before starting a CBD routine.

The study in quotes

“There is an increasing requirement for dogs to fit into human lifestyles which can cause stress and anxiety to both people and their pets.”

“Separation-related anxiety is one of the most reported stress-related issues in pet dogs, making up to 50% of referral cases to behaviorists.”

“Following the recent COVID-19 pandemic, the incidence of separation-related behaviors in dogs has increased and cases are expected to continue to rise.”

“One in four dogs suffer from travel-related problems.”

“If an animal experiences high levels of acute stress…[it] can lead to chronic physical and emotional health issues.”

“CBD has been shown to downregulate stress-related signals that can lead to chronic inflammation
and some pain responses in humans. Emerging evidence suggests CBD may also be efficacious in the treatment of anxiety in humans.”

“The mitigating effect of CBD treatment varied by measure and test, with some indicating a significant reduction in canine stress compared to the placebo group.”

“CBD is also increasingly used within the veterinary industry and it is reported that short-term oral dosing of CBD up to 20 mg/kg daily.”

“Forty healthy, adult dogs, twenty-two males and eighteen females of three breeds (17 Labrador Retrievers, 8 Beagles, and 15 Norfolk Terriers), with a mean age of 4.1 years (ranging from 1.2 to 9.4 years) participated in the study.”

“Dogs given CBD had lower concentrations of serum cortisol post-test compared to dogs given a placebo.”

“Some measures of stress in dogs were significantly affected following administration of CBD, suggesting it may have efficacy as an intervention for acute stress in dogs.”

“A single dose of CBD has a positive effect on reducing multiple aspects of canine stress during a car journey.”

“Dogs who received CBD were rated as being significantly less stressed, sad, tense, and uncomfortable and more explorative during the separation event than dogs who received the placebo.”

“A single 4 mg/kg dose of CBD may be generally effective in alleviating acute stress responses in dogs.”