Can Marijuana Kill Your Dog?
As marijuana becomes more mainstream, news media are finding new ways to sensationalize their marijuana coverage. One topic that has resurfaced lately is dogs and marijuana, specifically, is it good or bad for them? Unfortunately there is a lot of misinformation out there about canines and cannabis, leading NBC News to report “Marijuana poisoning on the rise in pets”.
Can marijuana “poison” your dog? We’ve been taught that marijuana is non-toxic to humans, but is it safe for your dog? Chocolate, raisins, grapes, garlic, onions, avocado, and macadamia nuts are delicious to us, but can range from sickening to life-threatening to your dog. And while everything more evolved than a sea squirt has an endocannabinoid system, can human-level quantities of weed overload a small dog’s system?
In the aforementioned NBC News story, Dr. Tina Wismer, the director of the Animal Poison Control Center explained, “Animals don’t react the same way as humans. Without treatment, dogs can go into comas and die.” Dr. Wismer singled out medicated edibles with high THC concentrations as most dangerous to canines, especially if combined in chocolate brownies or raisin cookies.
A 2012 study published in the Journal of Veterinary Emergency and Critical Care followed 125 dogs in Colorado that presented with marijuana ingestion from 2005-2010. Authors concluded, “Ingestion of baked goods made with medical grade tetrahydrocannabinol butter resulted in 2 deaths.” However, according to The Coloradoan, those two dogs died when they asphyxiated on their own vomit. Sad, to be sure, but can we call that a marijuana “toxicity”?
The Coloradoan also spoke with Ashley Harmon, a veterinarian at Fort Collins Veterinary Emergency and Rehabilitation. She says she’s seen more cases of people bringing in dogs who’ve ingested marijuana. She also says she’s seen two smaller dogs die from marijuana ingestion, one who ate a pound of pot brownies and another who ate a pound of pot butter. But is it the marijuana harming the dogs, or the ingredients in the edibles?
In 2013, researchers writing in the journal Topics in Companion Animal Medicine wrote “The minimum lethal oral dose for dogs for THC is more than 3 g/kg. Although the drug has a high margin of safety, deaths have been seen after ingestion of food products containing the more concentrated medical-grade THC butter.” But in 1973, scientists writing for the journal Toxicology and Applied Pharmacology noted “In dogs and monkeys, single oral doses of Δ9-THC and Δ8-THC between 3000 and 9000 mg/kg were nonlethal.” So, forty years ago, 3 to 9 grams THC per kilogram of body weight was non-lethal to a dog, but last year, 3 grams THC per kilogram of body weight is the minimum lethal dose. Confused yet?
Consider that in those studies, that’s 3 g/kg of THC given orally, not pot itself. A 2004 review published in the Journal of Veterinary and Human Toxicology looked at 213 incidents where dogs ate actual pot from 1998-2001. “The marijuana ingested ranged from 1/2 to 90 g,” the scientists wrote, “The lowest dose at which signs occurred was 84.7 mg/kg and the highest reported dose was 26.8 g/kg.” And they found, even with a dog eating almost an ounce of ganja per kilogram of its weight, “All followed animals made full recoveries.”
In terms of pure THC injected into dogs rather than eaten, researchers in 1983 found “the dose of THC which kills 50 per cent of animals (LD50) when administered intravenously is … 130mg/kg in the dog.” For comparison’s sake, pure synthetic THC Marinol pills that are prescribed to humans come in 2.5 mg, 5 mg, and 10 mg oral dosages and the THC you’ll get in a package of Colorado medicated edibles ranges from 50 mg to 125 mg.
So, can marijuana kill your dog? Technically, yes, but realistically, probably not. Your dog would have to eat a pound or more of strong pot or edibles, and be a smaller-sized dog, and you’d have to ignore its symptoms and the dog would have to experience some really bad luck, like passing out and choking on its vomit or, in the case of a chihuahua in New Zealand, experiencing hypothermia when the same blood vessel dilation that makes your eyes red made the dog radiate away all its body heat.
Numerous veterinarians have written about the possibility of coma and death in rare cases from marijuana ingestion, but they all note that most dogs will recover if given proper care. Cheryl K. Smith writing for Compassion Center in Eugene, Oregon, identifies the common signs of canine marijuana ingestion and suggests the following regimen:
The most common clinical effects of marijuana ingestion in pets are depression and listlessness, ataxia (loss of motor coordination, including loss of balance), vomiting and hypothermia (low body temperature). The animal’s eyes are often dilated and he may lose his appetite and not drink enough water. Other signs can include bradycardia (slow heartbeat) or tachycardia (fast heartbeat), agitation, vocalization, vomiting, diarrhea, hypersalivation (drooling), urinary incontinence, seizures, and in severe cases, coma or death. The neurotoxic effects of cannabis ingestion in animals usually occur within a half hour to two hours of eating it and usually last for about 12 hours. However, they can last for days because the cannabinoids are stored in fat.
The main treatment for marijuana toxicity is to give the animal activated charcoal orally. (Activated charcoal can be purchased at a drug store or feed store and is a good product to keep on hand.) The activated charcoal traps toxins as it goes through the digestive system. Other treatments include keeping the pet warm, minimizing sensory stimuli and, if she has vomited or had diarrhea, giving fluids. If you discover the marijuana ingestion right away, take your pet to a veterinarian, who can induce vomiting to prevent poisoning. After about a half hour or so, however, the anti-nausea effects of the cannabis make it more difficult to induce vomiting, and if the animal is lethargic, vomiting may lead to aspiration with further complications.
As for whether accidental canine marijuana overdose (my preferred term to “marijuana poisonings”) is on the rise, I believe it is a combination of two factors – legality makes pet parents more likely to visit a vet when Fido eats the stash rather than wait it out for fear of getting busted; and legality makes pet parents less likely to consistently hide their stash for fear of getting busted. But we needn’t overreact to the topic of dogs and marijuana, as there is a promising future in veterinary medical cannabis. Just be sure to get in the habit of keeping your marijuana out of reach of your pets (and your kids, too!)
