We know that marjijuana or cannabis is used for both recreation and medical purposes by humans. However, while some pets may benefit from medicinal cannabis, it’s important to be aware that cannabis poising in pets can and does happen.

Dr Marta Calvo Blanco, Head of Veterinary Operations and Education at eCS Vet, veterinary clinical educator, and holistic animal naturopath, explains more about cannabis poisoning in pets.

“Lately there have been a few media mentions of pets poisoned by cannabis. According to a research paper, ‘unattended ingestion of cannabis edibles was the most frequent cause of poisoning, but it was unclear what proportion of cannabis products had been obtained for human consumption versus medicinal consumption by pets.’

Dr Calvo Blanco says the fact is there are far more cannabinoid products, illegal or not, for humans than there are medicinal products for pets. “We only need to look online to see how many cannabis-based homemade or commercial edibles (baked goods, candies, chocolate bars etc) there are for humans compared to cannabinoid treats or medicine for animals.”

Of course, the issue is cannabis poisoning in pets, but given the fact that some pet owners and vets are using cannabis to treat pets many people may not understand why this poisoning is happening.

Understanding CBD Use in Pets

Dr Calvo Blanco explains, “Cannabis Sativa is a plant that has hundreds of different molecules and some of them belong to the same chemical group name ‘cannabinoids’. CBD and THC are the two most recognised and studied molecules of this group. To be more precise, they are called ‘phytocannabinoids’—since they are naturally produced in a plant.

“While CBD has no psychoactive effect, it can affect the neurologic function. As such, it’s being used in humans for its medicinal purpose to alleviate a variety of symptoms, including those associated with epilepsy, chronic pain, anxiety, and nausea. In the last few years, several studies examining CBD in animals have been published, and its use is spreading among different species for different situations like pain and inflammation, stress and anxiety, immunity issues, and cancer.

“Unlike CBD, THC does have psychoactive effects. Therefore, is highly used for recreational purpose by humans, but it also has many beneficial and medical properties when taken under medical or veterinary control for certain circumstances.

“Many animals are more sensitive to THC than humans. This is especially so for dogs or rodents, since they have a higher number of receptors for psychoactive cannabinoids. This makes them highly reactive to very small amounts and when a proper titration under veterinary supervision is not followed. According to research “Cannabis poisoning in pets was most frequently seen in dogs, but cases were also reported in cats, iguanas, ferrets, horses, and cockatoos.”

The Presence of Other Toxins

“Currently, most cannabinoid products for animals do not contain THC, either due to legal regulations or the manufacturer’s concerns about side effects. However, most human homemade or commercial edible goods (many of them available without any legal control) have higher THC and cannabis concentrations than the therapeutically recommended ones for animals.

“Additionally, most common—unregulated or not—human edible products are commercial chocolates and gummies, and brownies or cookies made at home. This increases the risk of intoxication due to the presence of chocolate or other human foods that also pose risk for poisoning in dogs. For example, ingredients frequently found in these products include xylitol, grapes/raisins, and macadamia nuts.

“There is growing evidence to suggest that many pet owners are already accessing unregulated cannabis products from the internet for their pets. Indeed, one survey in Canada stated that 79.8% of respondents had bought a cannabis product for their canine (Kogan et al. 2019). The authors also noted that veterinarians in Canada were the source of advice about cannabinoid products in only 25.3% of cases. This is problematic as it means that veterinarians are not able to assist in the safe administration of these products.”

The Good News

“Despite all this, there is some positive news. This research and all the previous studies relating to the safety or risk of cannabinoids for animals, agree that most cases of cannabis poisoning were benign. Most animals were treated by their vets with outpatient monitoring, and nearly all animals recovered completely, suggesting that most cannabis toxicoses do not result in long-term ill effects.

“Even though some deaths were reported in association with cannabis toxicosis, the presence of confounders such as toxins, and underlying conditions cannot be ruled out, and they can certainly be the main cause. “

Dr Calvo Blanco says the real focus should be on protecting our furry friends from the increase and uncontrolled cannabis market for humans.

“We need to create awareness among owners so that they never give their animals marijuana or human cannabinoids products. Furthermore, they should never give cannabinoid medications to their pets unless they have a veterinary prescription (which is also the only legal pathway in Australia) and are under veterinary support.

“More quality controls should be established to know the exact composition of the products. We also need more legal enforcement to reduce diversion to animals from the human side of this new market and more controlled access to the veterinarians to supervise the use of these products. Only then will our furry friend be safer.”

References

1. Prevalence and characteristics of cannabis-induced toxicoses in pets: Results from a survey of veterinarians in North America. Richard Quansah Amissah, Nadine A. VogtID, Chuyun Chen, Karolina Urban, Jibran Khokhar. Plose One Journal. Apr 2022.

2. Toxicology of marijuana, synthetic cannabinoids, and cannabidiol in dogs and cats. Ahna Brutlag and Holly Hommerding. Veterinary Clinics: Small Animal Practice, 48(6), pp.1087-1102. Nov 2018.