As marijuana has become legal for medicinal or recreational use in much of the U.S., veterinary emergency rooms have seen a corresponding rise in dogs coming through the door high.
The good news is that marijuana poisoning in dogs is rarely fatal. However, it can cause a distinctive and even alarming set of symptoms. Any dog suspected of ingesting the drug should see a veterinarian right away.
Why Cases Have Increased Over Time
As cannabis laws have changed across the country, exposure among pets has increased. In 1996, California became the first state to legalize cannabis use for medicinal purposes, and many states now allow medical or recreational use.
In 2012, a retrospective clinical study examined marijuana toxicosis in dogs in Colorado between 2005 and 2010 and found a four-fold increase in cases reported to two veterinary hospitals after medical marijuana was legalized.
More recently, however, that upward trend in calls may be leveling off. “Calls to Pet Poison Helpline regarding marijuana/THC have remained fairly steady over the last few years after a sharp increase and then decline,” says Dr. Renee D. Schmid, DVM, DABT, DABVT, Director of Veterinary Medicine and Senior Veterinary Toxicologist at Pet Poison Helpline.
Dr. Schmid explains that this decrease in calls may reflect changing behavior rather than reduced exposure. “As more states legalize marijuana, it is unlikely fewer pets are being exposed to marijuana, but more likely that pet owners are comfortable talking with their veterinarian about marijuana exposure with their pets, resulting in fewer calls to Pet Poison Helpline,” she says.
How Dogs Are Exposed to Marijuana
Dogs are more commonly affected by marijuana toxicosis than cats, largely because they’re more likely to consume edible cannabis products.
Many exposures occur when dogs eat baked goods containing marijuana, especially if they tend to take food from counters. However, other sources of exposure are also possible, including:
- Eating any part of the actual plant, including the leaves, seeds, stems, and flowers
- Inhaling secondhand smoke
- Consuming hashish oil
- Eating the feces of a person or animal that has ingested cannabis
Symptoms of Marijuana Poisoning in Dogs
The psychoactive compound in marijuana, tetrahydrocannabinol (THC), affects dogs more strongly than humans. Symptoms usually appear within 30 minutes to an hour after ingestion, or sooner if the drug is inhaled.
Dr. Stacy Meola, DVM, MS, DACVECC is the Associate Medical Director for Wheat Ridge Animal Hospital in Colorado and participated in the previously mentioned study. She explains that “the most common sign is stumbling and crossing over their feet, and walking like they are drunk (ataxic).”
In fact, 88% of the dogs in the study showed this lack of coordination. Around 50% of dogs also appeared lethargic with dilated pupils, and showed increased sensitivity to movement, flinching in reaction to fast movements toward their face.
Other symptoms of marijuana poisoning may include:
- Urinary incontinence
- Vomiting
- Tremors and shaking
- Agitation
In more severe cases, dogs may also become comatose.
How Veterinarians Diagnose Marijuana Poisoning
Diagnosing marijuana toxicosis in dogs relies heavily on a veterinarian’s ability to combine clinical observations with a reliable history of possible exposure. Because pets cannot communicate what they’ve ingested, details from the owner about access to cannabis products often play a critical role.
Veterinarians typically look for the characteristic neurologic signs associated with THC exposure. These signs, along with the timing of symptom onset, can strongly point toward cannabis ingestion.
Testing options are limited. Standard human drug screening tests aren’t always reliable for dogs and may produce false positives or negatives. As a result, veterinarians generally don’t rely on these tests alone. Instead, diagnosis is most often based on a combination of exposure history, clinical signs, and the exclusion of other possible causes of neurologic symptoms.
Treatment of Marijuana Poisoning in Dogs
Treatment depends on how severely the dog is affected. Mild cases may be managed at home with veterinary guidance. More serious cases usually require hospitalization for monitoring and supportive care such as intravenous fluids.
In more severe situations, specialized treatment may be recommended. “In severely affected animals, we recommend a treatment called intralipid therapy, which is an infusion of lipid (the fat used in IV nutrition support) to help bind the marijuana and allow it to be eliminated from the body faster,” Dr. Meola says.
With appropriate care, most dogs recover fully within one to two days.
Prevention and Safe Storage at Home
Because most cases involve accidental ingestion, simple household precautions can significantly reduce a dog’s risk of marijuana exposure.
Always store cannabis products in closed containers and out of reach, ideally in cabinets or other locations pets cannot access. Edibles are especially risky since they often smell appealing to dogs and may contain other toxic ingredients (like chocolate or xylitol).
It’s also important to avoid leaving marijuana unattended on counters, tables, or in bags where a curious dog could access it. Always dispose of used packaging or partially consumed products securely, rather than in an easily accessible trash can.
Limiting pets’ exposure to secondhand smoke is also recommended, as inhalation can lead to symptoms in some dogs.
Why It’s Important to Seek Veterinary Support
Although marijuana toxicosis is rarely fatal, it still requires veterinary evaluation. Dr. Meola notes that fatalities from marijuana ingestion alone are extremely rare. However, complications can arise when cannabis is combined with other toxic ingredients.
Many cases of marijuana toxicosis in dogs involve combining the drug with chocolate or artificial sweeteners such as xylitol, both of which are dangerous to dogs. Highly concentrated products, such as marijuana butter used in baked goods, can also increase the risk of more serious symptoms.
Because marijuana potency varies and dosing isn’t standardized, it is impossible to know exactly how much a dog has ingested. Regardless of how your dog’s marijuana ingestion occurs, you should always seek veterinary advice. “Because the potency of marijuana is variable and the amount in edibles is not regulated by a regulatory agency, it is very hard to know exactly how much a dog has ingested,” explains Dr. Meola. “With that said, we also do not know a toxic or fatal dose when inhaled or ingested, so it is always best to have a pet evaluated.”
This article is intended solely as general guidance, and does not constitute health or other professional advice. Individual situations and applicable laws vary by jurisdiction, and you are encouraged to obtain appropriate advice from qualified professionals in the applicable jurisdictions. We make no representations or warranties concerning any course of action taken by any person following or otherwise using the information offered or provided in this article, including any such information associated with and provided in connection with third-party products, and we will not be liable for any direct, indirect, consequential, special, exemplary or other damages that may result, including but not limited to economic loss, injury, illness or death.