Marijuana Toxicity in Pets

Marijuana is a popular recreational drug that is used by millions of people worldwide.

As veterinary professionals, we occasionally see our canine friends come in showing signs of a toxicity ingestion. Marijuana toxicity can look similar to other toxin ingestions. We rely heavily on the owners to give us all relevant information to properly assess and treat the pet.

Some people may feel embarrassed or concerned, they may be reported for possessing this substance. However, veterinary hospitals believe the pets’ health and wellbeing are the main priority, and we need to be aware of this possibility to properly diagnose and treat your pet. There is no obligation for staff to report.


“THC” or delta 9 tetrahydrocannabinol is the active ingredient in marijuana.

Regular marijuana is commonly composed of 1-8% THC while hashish (the flowering tops of the plant) can contain up to 10% THC.


  • Incoordination
  • Listlessness
  • Dilated pupils
  • Slow heart rate
  • Urinary incontinence
  • Drowsiness (may begin to fall over but catches balance)


Clinical signs can begin 30-90 minutes after ingestion. The effects of marijuana on pets can last for days.

If you know your animal has ingestion marijuana (or any other substance) your pet should be seen immediately.

If ingestion happened 30 minutes or less, it may be possible to induce vomiting (however, because of THC’s anti-nauseate properties this treatment method is not always effective). Also, if the patient is extremely sedate then inducing vomiting could be hazardous.

Activated charcoal is a liquid material that the animal can ingest to trap toxins and eliminate them from the body. This method of treatment can be effective if ingestion occurred recently.

It is possible your pet may need to be hospitalized, have intravenous fluids and be monitored closely until the symptoms wear off. The chance of fatality due strictly to marijuana toxicity is small but definitely possible (especially if they have underlying health issues).

Bottom line: seek medical attention if you think he/she has ingested marijuana.


Dartmouth Vet Hospital took wonderful care of my first dog. Maggie had some behavioural issues, all the staff were amazing…

Jaime Aitken

My wife brought our puppy in this morning. We were extremely worried. They saw him very quickly, were kind, compassionate…

Dave Snow

We’ve been with Dartmouth vet a long time! My boy is super nervous but always has a good time here.…

Marcy Lecky-nickerson

Dr. O’Leary was absolutely amazing as was Amanda . Dr. O’Leary took care of any concerns and questions, explained what…

Nyssa G.

This is the most patient and caring staff I have ever encountered. I have been with them for almost 10…

Livia Peyton


The Risks of Being an Outdoor Cat

Cats are curious creatures who love to roam and explore. The outside world is full of birds to hunt, trees to climb and sun patches to roll in - so why doesn’t everyone let their cat go outside?

Read More
See All Articles