Weed Could Make Dogs Less Aggressive to Humans

A new study published in 'Nature' found cannabis extract CBD hugely reduced aggressive behaviour towards humans in shelter dogs.
Weed Could Make Dogs Less Aggressive to Humans
Photo: Carsten Rehder/picture alliance via Getty Images

Giving stressed out shelter dogs CBD, the non-intoxicating cannabis extract, makes them less aggressive to humans, a new study has found. 

The research, published in Nature’s ‘Scientific Reports’, suggests CBD could be beneficial for dogs who spend their lives holed-up in kennels after being rescued from the streets or abusive owners.


“Our results clearly suggest that CBD treatment might be effectively used to improve welfare in dogs housed in a shelter,” said the study authors. “If CBD treatment causes a reduction in the aggressive behaviour of the dogs, this effect, in turn, might improve the relationships between the dogs and the staff of the kennel.” 

CBD works on the body’s endocannabinoid system, a “master regulator” involved with all kinds of biological processes, especially the immune and nervous systems. Like many animals, dogs also have an endocannabinoid system, so in theory a drug like CBD that can reduce anxiety in humans may do the same in canines.

To test this theory, researchers used 24 dogs at Muratella, the municipal dog shelter in Rome, Italy. The selected dogs needed to exhibit certain negative behaviours such as eating faeces, licking cage walls, destroying objects or self-injuring attacks. Other aggressive behaviours included growling, raised fur, bared teeth, and attacking the bars of the cage. Finding dogs that fit this criteria wasn’t difficult—out of the 400 dogs at the shelter, the researchers reported 90 percent exhibited some kind of stress.

For the next 45 days, 12 dogs were given meat containing extra virgin olive oil mixed with CBD, while another dozen were given a placebo. Both were well-tolerated by the dogs.


Aggressive behaviour in the CBD group dropped significantly, although it didn’t seem to have as much impact on other stressful behaviour, such as excessive scratching. The CBD didn’t make the dogs drowsy or any less active, so the reduction in aggression likely isn’t due to the dogs being sedated.

The study comes in the wake of a rising trend in people giving CBD to their pet dogs to help with problems such as pain and anxiety. 

Last month America’s most famous “homemaker”, Martha Stewart, supposedly known as M. Diddy while in prison following an insider trading scandal in 2004, launched her own line of gourmet CBD dog treats. Even before the science catches up, companies like Canopy Growth, one of the world’s largest cannabis corporations, are rolling out bacon-flavored tinctures for dogs. 

Giving dogs CBD has been studied since at least the 1980s, but there’s still a lot we don’t know about this drug in humans, let alone in animals. Until now, the trend of giving a weed extract to dogs has been largely  based on anecdotal reports that it can soothe their anxiety from things like fireworks or temper attachment disorders.  

While some people have revealed their terminally ill pets have been helped by CBD, others are less convinced about the weed extract’s use for dogs.   

Alicia McCarty, a dog rescuer for about a decade, says she’s tried a multitude of brands and hasn’t noticed any difference. “I know 99% of people swear by CBD, but I do not,” McCarty said. “I’ve been in animal rescue for many years, focusing on giant breeds. I was really hopeful that CBD would help with the magnitude of joint issues they all have, and it didn’t do anything. Unfortunately, I had to keep them on traditional medicines. My English Mastiff who had extreme anxiety and horrible arthritis and dysplasia got even more aggressive as his pain got worse. The CBD didn’t change a thing.”

The study authors called for more research with a larger sample size. “This would be certainly valuable, because the potential for improving the welfare of dogs in shelters is priceless,” they said.