Marijuana Intoxication in Dogs and Cats

By Lynn Buzhardt, DVM

Care & Wellness

marijuana_toxicity_in_petsRead the title. Develop the image. Dogs and cats lounging on the sofa with goofy grins on their faces giggling at jokes that aren’t funny. The idea of pets getting high on marijuana may seem comical, but it’s no laughing matter. Nor is it a new concept.

The traditional Cannabis plant has been around for centuries providing psychoactive resins that affect the brains of man and his four-footed companions. The term “marijuana” refers to the tobacco-like product made from dried Cannabis leaves. The leaves contain more than 400 different chemicals but tetrahydrocannabinol (THC) is the most potent psychogenic portion.

"…marijuana toxicity in pets is on the rise."

Marijuana is not new, but it’s still the most popular illicit drug in the United States. Here’s what IS new: with the legalization and decriminalization of the product, plus the availability of synthetic versions, marijuana toxicity in pets is on the rise.

How do pets become intoxicated?

Dogs and cats are poisoned by marijuana by inhaling second-hand smoke, eating marijuana-laced food, or scarfing down the stash directly. Most partaking pet owners protect their product, but curious pets may circumvent these precautions. When a pet finds a bag of marijuana on the coffee table or batch of brownies on the kitchen counter, trouble lies ahead. And some irresponsible pet owners put their pets at risk by offering laced treats or knowingly exposing them to second-hand smoke.

"Accurately admitting when and how much marijuana was consumed or inhaled will help the
veterinarian outline an effective treatment
plan in a timely manner."

Regardless of how your pet “got high”, being a responsible pet owner plays a large role in his safe recovery. Accurately admitting when and how much marijuana was consumed or inhaled will help the veterinarian outline an effective treatment plan in a timely manner.

How does marijuana affect pets?

Like most drugs, the effects of marijuana are based on chemistry. The drug enters the body via inhalation or ingestion and binds with specific neuro-receptors in the brain, altering normal neurotransmitter function. THC interacts with neurotransmitters such as norepinephrine, dopamine, serotonin, and acetylcholine. Humans and pets have two receptors in their bodies. CB1 affects the central nervous system and CB2 affects the peripheral tissues. Although all the pharmacologic mechanisms triggered by cannabinoids have not been identified, it is thought t hat CB1 is responsible for most of the effects of marijuana.

Everything that enters the body has to exit the body.THC is very lipid-soluble, which means that it is easily stored in the fatty tissue in the liver, brain, and kidneys before being eliminated from the body. THC is metabolized in the liver and the majority (65-90%) is excreted in the feces while a small percentage (10-35%) is eliminated through the kidneys. The drug has to be metabolized and excreted for the effects to wear off.

How toxic is marijuana?

One of the social drugs, marijuana is considered to have a high margin of safety for people; however, not all people, and certainly not all pets, follow a single pattern of intoxication. A small amount may affect one pet more than another, so there is no official safe level of exposure.

"Luckily, marijuana intoxication is seldom fatal."

Luckily, marijuana intoxication is seldom fatal. The average marijuana cigarette contains about 150 mg of THC. The minimum lethal oral dose of THC for pets is fairly high; however, deaths have been noted after ingestion of foods containing highly concentrated marijuana such as medical-grade THC. In fact, fatalities were very rare until the development of medical-grade products.

What are the signs of marijuana intoxication?

Many of the clinical effects of intoxication are neurological. Pets become wobbly and uncoordinated. They may be hyperactive, disoriented, and very vocal. Their pupils dilate giving them a wild-eyed appearance and they may drool excessively. In severe cases, tremors, seizures and coma can result.

"these side effects are usually short-lived but they can still be dangerous"

Physical signs include low or elevated heart rate and blood pressure. Lethargy, drop in body temperature and respiratory depression occur. Fortunately, these side effects are usually short-lived but they can still be dangerous and make the pet quite miserable.

How is intoxication diagnosed?

Usually, an accurate history and physical exam point to the diagnosis. There are tests to determine the level of THC in the urine, but the results take time making them impractical. Human urine drug-screening tests are quicker, but are not dependable in pets. That’s why it is imperative that responsible pet owners provide accurate information regarding the pet’s exposure.

How is intoxication treated?

When a toxin enters the body, the first line of defense is often to get it out! If the ingestion is discovered right away, the veterinarian may induce vomiting to prevent further absorption of the toxin. Two factors may interfere with this early defensive strategy. First, the problem may only manifest itself after the effects of the drug have taken hold, which means it’s already in the system. Secondly, marijuana has an anti-emetic effect which inhibits vomiting and reduces the ability to purge the body of the toxin. In life-threatening cases, the stomach may be pumped (gastric lavage). Activated charcoal may be administered every 6-8 hours to neutralize the toxin. Enemas are also used to reduce toxin absorption from the GI tract.

The second line of defense in marijuana toxicity involves providing supportive care until the effects of the drug wear off. Medications to regulate the pet’s heart rate and respiration are used if needed. Since the pet may be lethargic with no desire to eat or drink, IV fluids can prevent dehydration and maintain organ function. Anti-anxiety medications can minimize agitation. To prevent self trauma while the pet is disoriented and uncoordinated, he is confined to a safe, comfortable space. Noise is kept to a minimum to decrease sensory stimulation.

 The Bottom Line

The bottom line when it comes to marijuana use and pets is: Be careful. Keep all forms of marijuana, medical or recreational, out of reach of your pet. Then perhaps the startling 200% increase in marijuana toxicity cases called in to the Pet Poison Helpline will begin to decline. If you notice suspicious behavior in your dog or cat take your pet to the veterinarian or the nearest emergency facility.

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