Is Marijuana Poisonous to Dogs and Cats? – THC Toxicity Guide

Marijuana (Cannabis sativa) is toxic to dogs, cats, and horses. The ASPCA lists cannabis as toxic to all three species. The active compound, THC (delta-9-tetrahydrocannabinol), causes serious neurological effects in animals. Children are also far more vulnerable to THC than adults and can become seriously ill from consuming cannabis products.

What Part of the Plant Is Toxic

The entire cannabis plant contains THC, though concentrations vary by part. The flowers (buds) and leaves contain the highest amounts. Seeds contain less. Cannabis edibles (food products) are a growing source of pet poisoning because they are highly concentrated and often smell appealing to animals. Dried plant material, fresh plant material, and cannabis oils or concentrates are all dangerous.

THC acts on the endocannabinoid system. Animals have significantly more cannabinoid receptors in certain brain regions than humans do, which is why the same amount of THC causes much more severe effects in dogs and cats than in adult humans.

Symptoms of Marijuana Ingestion

Dogs and cats: Symptoms typically appear within 30 minutes to a few hours of ingestion and can last for hours to days depending on the dose. Common signs include:

• Prolonged depression and lethargy
• Incoordination and difficulty walking
• Excessive drooling or dry mouth
• Dilated pupils
• Low blood pressure and low body temperature
• Slow heart rate
• Vomiting, which is dangerous if the animal is also sedated
• Tremors or muscle twitching
• Seizures in severe cases
• Coma (rare but documented)

Small dogs and cats are at greatest risk because a smaller amount of THC causes proportionally higher blood concentrations.

Humans and children: In healthy adults, marijuana causes intoxication rather than poisoning, and deaths from cannabis alone are extremely rare. However, children are a different matter. Young children who ingest cannabis edibles can experience serious effects including severe sedation, slowed breathing, and loss of consciousness. This is a medical emergency. Legality of cannabis varies by jurisdiction; the safety concern exists regardless of legal status.

What to Do If Your Pet or Child Ingests Marijuana

1. Stay calm and gather information: what was ingested, how much, and when.
2. Do not try to treat at home. Do not induce vomiting without professional guidance.
3. Call poison control at 1-800-222-1222 (US) or your vet immediately.
4. If your pet is losing consciousness, breathing irregularly, or having seizures, go to an emergency vet clinic now.
5. For a child who has ingested cannabis, call poison control or go to an emergency room. Be honest with medical staff about what was consumed; they need this information to treat correctly.

Do not wait to see if symptoms resolve on their own. THC toxicity in animals can worsen over several hours.

Safe Handling and Storage

If you use cannabis products, the most effective safety measure is secure storage that pets and children cannot access. Dogs in particular are attracted to the smell of cannabis, and edibles often contain other ingredients (such as chocolate or xylitol) that add additional toxicity.

• Store all cannabis products in locked containers or high, secure locations.
• Do not leave edibles on countertops or in bags that pets or children can reach.
• Dispose of cannabis waste carefully; dogs will eat discarded plant material.
• Be aware that secondhand smoke affects pets: animals in a room where cannabis is smoked will inhale THC and can show signs of intoxication, though typically milder than direct ingestion.
• If you grow cannabis at home, fence the plants or keep them in a locked room that pets cannot enter.

What to Expect at the Vet

Veterinarians treat cannabis toxicity with supportive care. There is no specific antidote for THC. Treatment may include IV fluids, temperature monitoring, and anti-nausea medication. Most pets recover fully with appropriate care, though recovery can take several hours. Be honest with your vet about what your pet ingested; vets are not required to report this and need the information to treat your pet effectively.

Frequently Asked Questions

Can a dog die from eating marijuana? Death is rare but has occurred, particularly with very high-dose edibles. The risk is real enough to treat all cannabis ingestion as an emergency.

What if my pet only inhaled secondhand cannabis smoke? Secondhand smoke exposure typically causes milder symptoms than ingestion. Still monitor your pet and call your vet if any unusual behavior appears.

Are CBD products safe for pets? CBD (cannabidiol) without THC is a separate question from cannabis toxicity. Many vets are cautious about unregulated CBD products because quality and labeling vary widely. Ask your vet before giving any cannabis-derived product to a pet.

Is marijuana more dangerous to cats or dogs? Both species are affected. Dogs are more commonly poisoned simply because they are more likely to eat anything they find. Cats may also eat plant material or be exposed to edibles.

How long do symptoms last in pets? THC symptoms in dogs and cats typically last between 18 and 36 hours depending on the dose, though this varies. Veterinary monitoring is advisable for moderate to severe cases.