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Dr. Kevin Cosford, a specialist in small animal medicine at the WCVM Veterinary Medical Centre. Photo: Christina Weese.

Keep pot away from pets

Sleepiness, lethargy, a “drunken” stupor – these signs are no laughing matter when it comes to marijuana and your pets.

If you suspect your pet has ingested marijuana, whether in the form of an “edible” or the plant itself, it’s important to be upfront with your veterinarian about what has happened.

This will allow them to avoid more extensive — and expensive — tests and treatments that are unnecessary once they know what’s causing the clinical signs.

“Disclosing means less money is spent … and the appropriate care can be given,” says Dr. Kevin Cosford, a board-certified specialist in small animal internal medicine at the Western College of Veterinary Medicine (WCVM).

 According to the Saskatchewan Veterinary Medical Association, the organization that regulates the province’s veterinarians, a client telling their veterinarian a pet has been poisoned by marijuana would not be sufficient reason to report the client to the police. 

“Our goal is to take care of the pet,” says Cosford.

It’s also important to disclose what happened because the signs of marijuana toxicity can mimic other conditions, such as when a pet ingests antifreeze (ethylene glycol). Both issues cause the pet to appear drunk, stumbling and unco-ordinated.

“We need to know the difference because they are treated very differently,” says Cosford.

As the Canadian government moves toward legalizing marijuana for recreational use and human doctors prescribe it for medicinal use, veterinarians are seeing an upswing in marijuana-related cases.

“I would say that we probably see one to two suspected cases a week here now, whereas before it was kind of a rarity. It was, ‘Oh, the dog got into the marijuana,’ and everybody came to see what a dog that consumed marijuana looked like. Now we see them all the time. It has become common.” says Cosford.

Cosford says dogs are most often affected because they’re drawn to edibles that include the main psychoactive component in marijuana, delta-9-tetrahydrocannabinol (THC).

“Dogs are notorious for getting into things, but it’s exacerbated by the fact that some of these medical marijuana products are put into butter-type preparations.”

Cosford points to a paper based on research conducted by scientists in Colorado, where the frequency of marijuana toxicosis in dogs at two veterinary hospitals increased four times over five years following the legalization of recreational marijuana use in the state.

Other research indicates that dogs have a higher number of cannabinoid receptors in their brains, which would make them more susceptible than humans to the drug’s toxic effects.

Treatment for toxicosis usually involves intensive care including intravenous fluids and continuous monitoring of the pet until clinical signs subside. If a pet is comatose, veterinarians will need to manage the animal’s bladder and move the pet every couple of hours while waiting for the effect of the psychoactive resins to wear off. In extreme cases, marijuana toxicity can result in death but this is rare.  

Because THC levels vary from plant to plant, it’s impossible to determine how much THC is enough to cause harm.

Cosford is interested in investigating the potential cost of the treatment of marijuana exposure and pets so regulators can understand the potential impact of new government legislation on animal health.

Much of the current veterinary research surrounds marijuana toxicity in pets — scientists haven’t fully explored the potential for using marijuana to treat pets. Veterinarians aren’t legally allowed to prescribe marijuana under Health Canada regulations, and research into its use cannot be conducted at institutions like the University of Saskatchewan because marijuana is still classed as an illegal substance.

However, Cosford believes there could be a future for marijuana in veterinary medicine. More research needs to be done before veterinarians can start to treat pets with marijuana, whether it’s the THC or the non-psychoactive component called cannabidiol (CBD) that’s been shown to have positive health outcomes in humans.

“I can imagine in five years, 10 years, it will be very different. We’ll have more information,” he says.

Read more pet health articles in the Winter 2018 issue of Vet Topics.

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