Pot for Pets?
Well, with school out for the summer, I can catch my breath again. So, I am back from a hiatus of blog-writing, and I figured I would come back with a big bang! With the upcoming election and the potential legalization of marijuana, I think we need to talk about the potential threat to pets if the measure passes. In case you have forgotten, I wrote a blog on CBD oil a few months ago, which you can refer to if interested, and I still can’t recommend CBD oil. However, with legalization of marijuana, we are really worried about THC exposure rather than CBD exposure.
With legalization of marijuana in several states over the last few years, there has been an increased incidence of accidental exposures in dogs, cats, and children. There are a couple of articles that I will reference, and basically, the articles conclude that there has been an increased exposure in children less than 9 years of age (predominantly boys). Neurological signs are seen most frequently, and the route of exposure is food ingestion. The articles report significant increases in major and moderate clinical signs, and they report a 30% increase in call rates to human poison control centers. No change in call rates was reported in states where marijuana remains illegal.
In Colorado, a four-fold increase in THC toxicosis has been seen in pets since medical marijuana was legalized.
The toxic ingredient in marijuana is tetrahydrocannabinol (THC), and it affects cannabinoid receptors in the brain. Some of these receptors are stimulatory, and others are inhibitory. Marijuana is absorbed orally or via inhalation, and it is rapidly absorbed. Marijuana is eliminated through the liver, bile, feces, and urine. Clinical signs associated with intoxication usually occur within 30 minutes, and they can last up to 3 days!
In pets (dogs primarily), the most common route of exposure is accidental ingestion. This can occur if the dogs eat the end of a joint that they pick up off the ground. Brownies, cookies, and butter (we will come back to this one) can be eaten, and there are reports of dogs licking the ashes from an ashtray.
Clinical signs can be neurological (ataxia, disorientation, agitation, enlarged pupils, tremors, seizures, coma), gastrointestinal (hypersalivation or vomiting, although vomiting is often minimized by the marijuana), or cardiac (slow heart rate, rapid heart rate, hypoventilation). Other clinical signs reported include changes in body temperature, either hypothermia or hyperthermia, and urinary incontinence.
There are no changes on screening lab work that are diagnostic for marijuana intoxication, but screening lab work and/or blood gas evaluation may be required in patients with medical conditions or older pets. Urine drug screening tests can be performed, and these are available over-the-counter. However, dogs metabolize THC differently than people, and this can lead to false negative results.
No specific treatment exists for marijuana intoxication. Decontamination, i.e., induction of vomiting, can be performed if a large amount of marijuana is suspected of being present in the stomach. Because THC can prevent vomiting (hence its use as an anti-emetic in human cancer patients), this may prove extremely unrewarding. In addition, induction of vomiting in dogs that are profoundly sedated from the marijuana should not be attempted as it can lead to aspiration. In fact, many veterinarians who see these patients will administer an anti-emetic to try to prevent aspiration pneumonia.
Dogs can be given activated charcoal to bind the toxins as they travel through the GI tract. Because marijuana is recirculated from the gut to the liver over and over again, multiple doses of activated charcoal may need to be given. Remember I mentioned butter? Butter is high in fat, and THC accumulates in fat, leading to severe intoxications. In fact, the majority of deaths in dogs from marijuana have been the result of butter ingestion, and Dr. Gwaltney-Brant, who is a boarded veterinary toxicologist, recommends treating these dogs ultra-aggressively, possibly even with IV lipid emulsion infusion therapy (basically the body is overloaded with fats).
In dogs that are hypoventrilating (not breathing well), intubation and mechanical ventilation may be required. Dogs that have heart rates that are too slow or too rapid may require medications to control their heart rate.
Although there is no “cure” for marijuana intoxication, most of the pets will recover with aggressive supportive therapy, but in all honesty, as Ben Franklin would say, an ounce of prevention is worth a pound of cure.
As I conclude, here are some interesting points to ponder that came from Colorado veterinarians:
With the legalization of marijuana, more owners will reek of marijuana, but of greater significance, more of them will be driving on the roads while still high.
More pets will be exposed as they eat remnants of marijuana.
Since it is legal, owners will be more willing to admit marijuana exposure, at least allowing us to treat rapidly and aggressively to save their lives.
Let’s say no to pot for pets!
Wang GS, Roosevelt G, LeLait MC, et al. Association of unintentional pediatric exposures with decriminalization of marijuana in the United States. Ann Emerg Med 2014;53(6):684-689.
Wang GS, Roosevelt G, Heard K. Pediatric marijuana exposures in a medical marijuana state. JAMA Pediatr 2014;167(7):630-633.