Does the Legalization of Marijuana Unduly Threaten Pets?

Though never a personal favorite, marijuana was part of my life for roughly 25 years. It was omnipresent during my schooling years, of course. It even followed me into my respectable life as a responsible single mother, when friends would want to unwind over something more forgiving than a crushing round of tequila shots. 

The fact that a middle-aged woman with a middle-class upbringing and a veterinary career to protect can offer this kind of statement without fear of recrimination or reprisal is a testament to just how pervasive and culturally normalized this drug has become in just a few short years.

Sure, marijuana’s been making its rounds in popular culture since well before its notorious heyday (long before I was born into a strict, teetotaling immigrant family), but it’s only been in the past decade or so that its patina of disrepute has noticeably dimmed. And now that widespread legal challenges are poised to further erode its infamy, it seems inevitable that pot will be a fact of life for us all –– like it or not. 

Which brings me to the point of this belated 4/20 post (April 20th is the unofficial annual holiday for marijuana devotees): 

Drug use –– medicinal or recreational, legal or not –– comes with responsibilities. But practically speaking, exercising caution responsibly is often at odds with the use of mind-altering substances like marijuana (my experience tells me so). Which may explain why geographic regions with legalized marijuana usage are experiencing a sharp uptick in marijuana toxicity among pets. 

If zesty online discussions on veterinary sites and casual collegial interaction at conferences are any measure, marijuana poisoning is an emerging issue in the veterinary community –– particularly among those in the emergency and critical care arena. Though I’ve seen my share of pot-addled animal patients, it was primarily in my role as an ER doc that I encountered these cases. But that was years ago. By all personal veterinary accounts, patient presentations for marijuana intoxication are up dramatically since I last saw the insides of an ER facility at midnight. 

But don’t take my community’s anecdotal word for it. Turns out there’s research on this very subject. In Colorado (where else?), two large animal ER facilities (one in Fort Collins at the Colorado State University teaching hospital and another in metropolitan Denver) reported a four-fold increase in marijuana intoxication cases over a five year period following the legalization of marijuana for medicinal use in that state.

Over its five-year course, this study tallied 125 canine cases of known exposure to cannabis, two of which died after ingesting butter infused with marijuana oils. But it could have been worse. Much worse. After all, the number of legal licenses granted during this period increased 146-fold. 

This study was published in 2012. Since then, Colorado and Washington have both legalized marijuana for recreational use as well as medicinal use, potentially opening the floodgates for far more reckless behavior than any licensed activity would tend to inspire. But we (as yet) have no numbers by which to measure any spike in marijuana poisonings among pets. If this research is any guide, however, the legalization of marijuana is taking a nasty toll. 

This invisible tax on animal lives is perhaps to be expected with the popularization of any drug, designed for any purpose. For perspective, consider that ibuprofen and acetaminophen alone probably kill more pets every year than all prescription drugs combined. They’re that poisonous. By comparison, death due to marijuana intoxication would seem a rarity. Milligram per milligram, it’s simply not as toxic.

Still, it’s a risk –– a growing one at that. And unless education on the subject accompanies the increased use of marijuana, morbidity and mortality will ensue. Still, I choose to remain optimistic on the subject. Here’s how I see it: 

• We need more smart, balanced posts like this one to inform both veterinary community and pet owners of the drug’s true risks (along with its much-touted potential rewards). I do believe that in time, with more education, marijuana users will adopt safer practices. 
• We also need more research, however, to tell us how much is too much and what we might expect in terms of therapeutic indications, safety, efficacy, dosage and treatment of intoxication. Once more firmly in hand, these will surely mitigate many of the risks.
• While not a new drug, consider that the excitement of legalization is likely to be a relatively short-lived phenomenon. I think that's partly what we're seeing now with this uptick in toxicity cases. 
• Moreover, it’s been my experience that with legalization comes the increased willingness of owners to "come clean.” At least some measure of this apparent spike in toxicity is likely attributable to increased presentation at veterinary hospitals. After all, with legalization and cultural normalization comes a greater sense of comfort when talking to a medical professional about their pet’s exposure to marijuana.

See? It’s not all doom and gloom. While marijuana’s relentless drive towards legalization and widespread cultural acceptance would seem unstoppable, its threat to innocent animals doesn’t have to be. So partake. Or don’t. But in the wake of this year’s 4/20, do your part and spread the word.