Cannabis poisoning in dogs: the signs, and what to do


Board-certified veterinary surgeon and founder and CEO of Dr. Cuddles, Dr. Mathieu Glassman, discusses cannabis poisoning in dogs and provides essential insights and guidance every dog owner needs to know …

How THC Affects Dogs

The physiological differences between dogs and humans in how they process THC, the primary psychoactive compound in cannabis, are significant. THC affects cannabinoid (CB1) receptors in the brain, impacting neurotransmitters like dopamine, serotonin, and gamma-aminobutyric acid (GABA). This can lead to both stimulatory and inhibitory signs in dogs. With a larger number of cannabinoid receptors in the brain compared with humans, dogs exhibit  increased sensitivity to the psychoactive properties of THC.

Additionally, and especially with the emergence of medical marijuana strains, the concentration of THC in marijuana has gone up considerably, and is approximately 10 times stronger than strains seen in the 1960s, an era infamous for its marijuana use.

Dogs also metabolise THC differently, rapidly absorbing it either orally or through inhalation, primarily eliminating it via the liver, bile, feces, and urine. THC’s enterohepatic recirculation – where THC that is excreted by the liver is reabsorbed by the intestines – intensifies its effects and potency in dogs. Despite the lethal dose for 50% of individuals (LD50) in dogs being exceptionally high, clinical signs of toxicity can manifest even at very low doses, as deaths related to marijuana ingestion have been reported between 3-9 g/kg.

Common Sources of Exposure

Dogs often come into accidental contact with cannabis through inhalation (second-hand smoke) or more commonly, ingestion. Ingestion can occur in various scenarios, such as consuming marijuana-laced food products (gummies, brownies and other edibles), finding and ingesting  discarded marijuana buds, or unintentional access to cannabis-infused products in the home.

Recognising Signs of Toxicity

Recognizing the signs of marijuana toxicity in dogs is crucial for timely intervention. These signs can vary from mild to severe and typically include central nervous system symptoms like ataxia (wobbliness), disorientation, hyperesthesia (painful response to non-painful stimulus), agitation, and more severe signs like seizures and coma. Gastrointestinal symptoms such as hypersalivation and vomiting, cardiopulmonary signs like bradycardia (low heart rate) or tachycardia (high heart rate), and miscellaneous signs such as urinary incontinence and temperature changes are also common. These signs can develop quickly, often within 30 minutes to 3 hours of exposure.

Treatment and Recommended Protocol

Treatment for cannabis intoxication should begin as soon as ingestion is suspected, and can be the difference between a mild and severe intoxication.

Clinical signs of marijuana toxicosis can escalate rapidly into severe conditions such as coma, bradycardia, hypotension, and seizures, prompt treatment is critical. Immediate first-response treatment can significantly mitigate the risk of long-term complications or even death due to cardiac or respiratory arrest. If cannabis poisoning is suspected, the following steps should be taken:

  • Initial Treatment

DO NOT induce vomiting. Given the antiemetic effect of THC, induced vomiting can actually be detrimental and pose a risk of aspiration pneumonia, especially if the dog is sedated or has a decreased gag reflex. Instead, administer an oral detoxifier preferably one that contains advanced activated charcoal, such as ReadyRESCUE, to immediately bind the THC and prevent systemic absorption. recognizing toxicity signs and initiating prompt treatment as close to the time of ingestion as possible is when absorption prevention is most effective.

  • Determine THC Quantity

After administration, the activated charcoal will immediately start binding toxins, preventing their absorption, minimizing their impact, and providing critical time to investigate the amount of THC ingested and determine next steps. Knowing the actual amount or the potential maximum amount of THC that could have been ingested is critical to assess toxicity levels and the best course of action.

  • Consult a Pet Care Professional

Prompt consultation with a vet or pet poison hotline is crucial. Providing your veterinary professional with your pets age, weight, any concurrent diseases and amount of toxin that was or could have been ingested will help the veterinarian determine If veterinary intervention or additional care is needed.

  • Supportive Care

Post ingestion care mainly involves fluid therapy, antiemetics, thermoregulation, and monitoring vital parameters. Severe cases may require more intensive treatments like mechanical ventilation or dialysis.

  • Preventative Care

If your dog is going to be in an environment where cannabis could be accessible, preventative administration of an adsorbent such as activated charcoal or activated carbon can be helpful to preemptively minimize the absorption of the THC from the gastrointestinal tract into the bloodstream in the event of ingestion.

As a seasoned veterinary surgeon with firsthand experience in addressing numerous emergency pet poisonings, I’ve come to appreciate the indispensable support that vet-approved first aid products at home can offer, providing initial and often critical assistance before professional care is accessible.

Whether cannabis products are present in your home or not, understanding the effects of THC, recognizing toxicity signs, and being equipped with at-home treatments stand as crucial elements of informed and prepared pet parenting. Such devotion significantly mitigates the associated risks of cannabis exposure, ensuring the safety and well-being of our cherished pets.

This is a guest essay by Dr. Mathieu Glassman. Want to write for us? Visit or email


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