Marijuana Toxicity in Pets: A Growing Problem With Serious Consequences

As the laws change and marijuana use becomes more frequent, marijuana toxicity in pets is on the rise.

Marijuana can be deadly for pets. By: Sluitertijd - fotografie | Vanderlaan
Marijuana can be toxic for pets. It’s no laughing matter. Photo: Sluitertijd – fotografie

With the legalization and decriminalization of marijuana in certain states, marijuana toxicity in pets is on the rise.

The Pet Poison Helpline has reported a 200% rise in marijuana cases in the past few years.

Every year, I treat the occasional potted-out poodle, but I’ve seen 3 in the past 3 months alone.


This is a nationwide trend.

In Colorado, one state where marijuana has been legalized, emergency hospitals have reported a rise in marijuana poisonings from 1–2 cases a month to 1 every other day.

Marijuana Toxicity in a Dog

By coincidence, after I started writing this article, I saw the worst emergency case of marijuana/chocolate toxicity in a dog I have ever seen.

My new little patient had all strikes against him:

  1. A small dog (14 pounds) …
  2. Ate a large amount of dark chocolate brownies …
  3. Loaded with hashish …
  4. And his caretakers didn’t realize this until they found him comatose, about 15 hours later.

Even if these folks had not told me what their little dog got into, his breath was a dead giveaway.

He reeked of marijuana. I’ve never smelled this strong of a pot smell on a dog before.

The good news? Our midnight brownie bandit is recovering and is going to make it.


He saved his own life by vomiting up a large amount of his hash bash, and then we supported him through his detox phase.

Here’s a quick video I put together for you. My canine patient is doing so much better now:

How Serious Is It If My Pet Ingests Pot?

Thankfully, we can usually relax and laugh — a little — when we see “a party animal” fall into our hospital.

Marijuana has a “wide margin of safety,” meaning it takes a great deal of the substance to be lethal. No marijuana deaths have been reported to the Pet Poison Helpline.

In a very few cases, deaths of little dogs have occurred from ingesting large quantities of food containing marijuana:

  • If a dog eats an entire tray of brownies containing marijuana or hashish, the situation is potentially life-threatening.
  • Even so, these deaths were extremely rare cases where people were also not around to notice the emergency. These intoxicated dogs probably could have been saved with medical intervention and support.

What Are the Signs of Marijuana Poisoning in a Dog or Cat?

  • Dilated eyes
  • Appearing drunk
  • Stumbling

Sound familiar?

If you are chilling with your pet, the pair of you will look just about the same. Your pet may also vomit, become agitated or exhibit urinary incontinence or urine dribbling.

Here’s a deeper look at the signs of marijuana toxicity in pets:

  1. Mydriasis. This term describes dilated pupils. Think of that glassy-eyed, dull but staring sort of look when someone is under the influence.
  2. Somnolent. This word is borrowed from human medicine when describing a patient with altered consciousness. Somnolent means the individual can be easily aroused but requires stimulation to stay awake. In other words, your stoned pet is continually nodding off. Somnolent is the state between lethargy and obtunded (unable to rouse).
  3. Head weaving at rest and listing. Dogs under the influence of marijuana are rolling their heads around and listing to one side or the other when trying to walk (ataxia). In other words, they look like a cartoon drunken sailor.
  4. Dribbling urine. Unlike many other toxicoses, pot almost always makes a pet dribble urine uncontrollably. If we notice this, marijuana should be high on the list of suspects.

With any luck, you’re not in the same condition, so you can get your dog or cat to the veterinarian.

THC-laced baked goods are a major culprit in canine marijuana toxicity. Photo: valtercirillo

Diagnosing Marijuana Toxicity in Pets

The intoxicated state of the pet is a big clue. But other, more serious toxins can create the same signs.

‘Fessing up to your vet is a great help, but many people are too embarrassed to admit to the marijuana. Often, they will have suspicions that will need to be confirmed.

If the person is truly unaware of any drug exposure, there is a quick tox screen available to vets that tests for cocaine, THC (marijuana), opiates, methamphetamines, benzodiazepines and oxycodone.

Being able to identify the drug helps us in treatment.

If the pet tests positive for THC and a non-pot-smoking mom or dad has brought the pet in, then an unpleasant conversation will be taking place when their teenager gets home from school.


Let’s Get Real … How Toxic Is Marijuana to My Pet, Usually?

All in all, ingestion of marijuana by a pet is fairly safe, at least compared to other drugs.

Most pets get into marijuana accidentally. They find the bag or the brownies and binge. If you’re honest and knowledgeable about the amount and source of the drug, it can help your vet a great deal with the treatment plan.

Occasionally I have had some kids get their dogs high deliberately, and this is just stupid. Unfortunately, people who exhibit this level of irresponsibility are probably not going to take their stoned dog to the vet.

Hopefully Mr. Buzz will be able to sleep off a small amount of marijuana without serious side effects such as seizure or coma while his human friends continue to party.

How Is It Treated?

Onset of symptoms after ingesting or inhaling marijuana is 30–60 minutes in most pets.

Depending on the dosage and strength of the drug, signs can last 18–36 hours.

If we have an intoxicated pet, supportive care is all we can do.

There is no antidote to reverse the effects of marijuana. If there were, I think a lot of young Americans would know about the “reverse pot pill.” Then they could walk back in their front door and not be so afraid of meeting mom or dad on the landing.

Treatment also includes:

  • Activated charcoal can be given to absorb some of the toxins.
  • IV fluids, anti-vomiting medication, temperature regulation, and controlling seizures or tremors are all part of the detox phase.

Basically, the pet just has to sleep it off under supervision.


Some clients have told me they were reluctant to “come clean” about their pet’s marijuana ingestion because they thought I would report them to the police.

Veterinarians have nothing to do with reporting your use or your pet’s marijuana use to the authorities.

Animal abuse is a different story, and we are responsible for reporting abuse — but accidental pot ingestion does not qualify.

Somnolence and listing to one side are both symptoms of marijuana toxicity in dogs. Photo: manfredrichter

Another Recent Case

We recently had a young person bring in her adorable little terrier mix buddy for staggering and strange neurological behavior.

After taking a look at the dog’s dilated, glazed eyes and observing his strange pattern of walking, we had our suspicions.

“No, I don’t think he could have gotten into anything. There’s nothing around. We watch him like a hawk. He woke up like this.”

After about an hour, the teetering terrier seemed quite a bit better.

I took him out for a little walk to assess his neurological status. He seemed somewhat uncomfortable in the rear end and stooped to poop. With some difficulty, Monsieur Terry pooped out some large cocktail almonds, at which point he seemed much happier.

I believe Monsieur partook in somebody’s pot the night before and then found some snacks to satisfy his munchies. Within a few hours he was as good as new.

Final Thoughts

Although marijuana has a large safety margin, it can still make your pet quite ill and neurologically impaired.

Baked laced goods seem to be much more of a danger. Where the human party animal might have 1–2 brownies and call it a night, the canine party animal will eat the entire tray. This can be very toxic.

There are more marijuana edibles around than ever before, so please: Keep your pets away from them.

Assume nothing about visitors. Old Uncle Morton just might have some weed in his coat pockets that may mean a trip to the emergency vet if your dog gets into it.

vet-cross60pThis pet health content was written by a veterinarian, Dr. Debora Lichtenberg, VMD. It was last reviewed Feb. 21, 2019.