With the increased accessibility of marijuana for medical and recreational purposes, the Pet Poison Helpline reports a 448% increase in cases involving dogs and cats ingesting marijuana or marijuana products.
Even though some studies have shown that marijuana can aid humans with certain health conditions, it is not safe for cats to ingest it in any form or to inhale secondhand marijuana smoke.
To better understand marijuana products and concerns in cats, it helps to understand the terminology:
Marijuana: Marijuana is a drug that’s composed of the leaves and flowers of plants in the genus Cannabis. While marijuana contains both THC and CBD, it has a higher concentration of THC.
Cannabis: While sometimes used interchangeably with the term marijuana, cannabis refers to the plant genus. There are three species of plants within the cannabis genus. Ranked in order of THC content, they are C. indica, C. sativa, and C. ruderalis.
THC: THC is the abbreviation and commonly used term for tetrahydrocannabinol. It is the main psychoactive compound of cannabis and one of over 100 compounds called cannabinoids that are found in the plant. THC is responsible for the “high” feeling associated with marijuana.
CBD: CBD is the abbreviation and commonly used term for cannabidiol. It is a popular herbal drug widely promoted for claims of various therapeutic benefits, but it does not have the same “high” feeling or addictive properties as THC. It is another one of the cannabinoids found in cannabis plants.
Hemp: Hemp is derived from varieties of C. sativa that contain lower concentrations of THC and higher concentrations of CBD.
Do Cats Have Cannabinoid Receptors?
Cannabinoids are compounds found in cannabis plants. The most notable and intoxicating cannabinoid is THC. Cannabinoid receptors respond to certain cannabinoids to certain degrees. Cats have cannabinoid receptors just like humans. In fact, there are two cannabinoid receptors (CB1 and CB2) found in all mammals (humans, cats, dogs), birds, reptiles, and fish.
CB1 receptors are known to be psychoactive (affecting the mind and neurologic processes) and can be found in the brain, fat, liver, and muscles. Dogs and cats have been shown to have a higher number of the CB1 receptors in the brain compared to humans. CB1 receptors are responsible for affecting the mind, alerting the mood, and the overall “high” feeling of marijuana. THC has a higher affinity for CB1 receptors, so marijuana often affects dogs and cats more than humans.
CB2 receptors play a strong role in immune function, and anti-inflammatory functions are mostly located in immune cells. CBD has a higher affinity for CB2 receptors, which is why humans and pets do not experience the same toxic effects with CBD as with THC.
How Does Marijuana Affect Cats?
Marijuana acts on the cannabinoid receptors (mainly CB1) to alter the brain’s chemistry to typically stimulate the pleasure zones, giving a “chill” or happy feeling, in people; however, in cats this can be a terrifying experience full of fear and paranoia.
THC is very lipid (fat) soluble, meaning it is stored in the body's fatty tissues and can be slowly released into the bloodstream. THC is metabolized mostly by the liver and excreted in feces and urine. However, due to lipid solubility, it can take up to 5 days after exposure for 80-90% of the marijuana to be eliminated.
It is important to note that catnip and marijuana are not similar in the way they work on cats. While cats under the influence of catnip can experience similar euphoric feelings denoted to humans when they consume marijuana, these two substances are not the same, and do not work the same in the cat’s body or brain. Catnip is considered more of a pheromone, and cats cannot overdose from catnip. Marijuana is very different and can be dangerous due to THC toxicity.
Is Marijuana Toxic to Cats?
Yes, marijuana is toxic to cats. However, the exact toxic dose is unknown. While the ASPCA reports marijuana toxicity is more common in dogs, cats make up about 3% of the marijuana toxicity cases. But this just means there is more information regarding marijuana toxicity in dogs, and much less research and data regarding cats. However, we do know that marijuana, particularly from the effects of THC, is toxic (but rarely lethal) to cats.
The good news is that in most situations, cats can fully recover from marijuana toxicity with no long-term effects. But not all people and pets will experience the same level of toxicity. Differences in ages, health status, and body size, as well as complications such as aspiration pneumonia, seizures, or existing heart problems, can affect an individual’s toxicity and ability to recover. Therefore, have your cat examined immediately by a veterinarian if you think they have ingested marijuana.
Cats typically have a more discerning palate than dogs, and they can become intoxicated by marijuana by ingesting cannabis or any other THC-containing product. Cats can also be exposed to secondhand smoke when they are in the same room as humans who are smoking marijuana. Even small amounts of THC-containing products can cause clinical signs and toxicity in cats, as they are smaller and have more CB1 receptors compared to humans.
Signs of Marijuana Toxicity in Cats
Clinical signs of marijuana toxicity are primarily neurological. They can start in as little as half an hour and last for several hours or even days. The possible clinical signs in cats include:
- Loss of coordination
- Dilated pupils
- Slow heart rate
- Low body temperature (which can become dangerously low)
- Vocalization or agitation
- Excessive drooling/vomiting/diarrhea
- Dribbling urine or loss of control of urination
If you notice any of these signs or believe your pet may have gotten into marijuana or a marijuana product, take them immediately to your local veterinarian or veterinary emergency hospital. Give your vet a specific description of the method of exposure (such as ingestion or aerosol), specific product (such as dried plant or edible), and any previous medical issues (such as heart disease or pancreatitis) for your cat.
Marijuana Products That Are Toxic to Cats
Some examples of marijuana products on the market that can be toxic to cats include:
Edibles: Edibles are food items containing marijuana. These can often be more toxic, as they tend to contain a higher level of THC than the plant itself and can pose a higher risk for poisoning pets. Another consideration when cats ingest edibles is to treat for any secondary toxicities. For example, if a cat eats chocolate pot brownies, they will also need treatment for chocolate toxicity.
Plant: THC is found in the leaves and flowering parts of the marijuana plants. A cat can become intoxicated from ingesting live plants, dried weed products, or marijuana cigarettes.
Cannabutter: Cannabutter is butter that has been infused with cannabis and may be used in homemade edibles. This form of marijuana toxicity poses an added risk of pancreatitis due to the high fat content of butter.
THC Vape Oil: THC vape oil is a type of cannabis extract made into a liquid for use in a vape, or electronic cigarette. Like edibles, vape oils tend to contain a higher concentration of THC and therefore can pose a higher risk to pets. Additionally, while unlikely, if the cat ingests the cartridge, there is a risk for foreign body obstruction.
Concentrates: Cannabis concentrate is a broad category referring to all products that have been extracted from the plant and are often used interchangeably with extracts. Concentrates may refer to products produced with commercial equipment or prepared in a home setting through dry processing, dry ice processing, water-based processing, combining heat and pressure, and using flammable and nonflammable solutes. Again, as the name implies, concentrates will likely be a concentrated form of THC and therefore increase its toxicity potential.
Tinctures: Tinctures of cannabis are most often an alcoholic cannabis concentrate. With these products, in addition to the concerns of concentrated THC, cats could also experience side effects from alcohol ingestion.
What to Do If Your Cat Is Exposed to Marijuana
Even if you don’t think your pet had access to marijuana or marijuana products, it should be on the list of possible causes if your cat shows the clinical signs and these products are in the household.
There is no need to feel nervous or embarrassed. Your vet is simply trying to gather information to help your pet. Diagnosis of marijuana exposure is typically through a combination of history and clinical signs. Since human drug tests for marijuana do not work well on dogs, and there is no data regarding their efficacy in cats, your vet is relying on you and your information to help make a diagnosis for your pet.
Treatment for Marijuana Toxicity in Cats
The veterinarian may induce vomiting if your cat ingested marijuana very recently and they are not yet showing any signs. They may also give the cat activated charcoal to bind any additional toxin.
There is no antidote for marijuana ingestion, so treatment is largely supportive care until the effects of the drug wear off. This may involve IV fluids to keep your cat hydrated, as well as anti-nausea medication, temperature support, and confinement to a quiet, comfortable place. A newer treatment called intralipid therapy may be recommended to help pull the THC out of the fatty tissues faster and shorten the clinical signs.
Most cats recover from marijuana exposure and do not have any long-term complications. However, do not forget to consider any secondary toxicities such as alcohol or chocolate ingestion.
Prevention is key, so never allow your cat to eat or inhale marijuana or marijuana-containing products. Store cannabis products with THC safely out of reach and do not expose your cat to any secondhand marijuana smoke.
- Donaldson, Caroline. ASPCApro. Marijuana Exposure in Animals.
- FAHA SV PhD, Griffiths J CVT. Understanding the endocannabinoid system in cats and dogs. IVC Journal. October 27, 2020.
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- National Institute on Drug Abuse. Cannabis (Marijuana) Concentrates DrugFacts. June 25, 2020.
- Pet Poison Helpline. Marijuana. March 2020.
- The Editors of Encyclopædia Britannica. Encyclopædia Britannica. Marijuana. 2019.
Featured Image: iStockphoto.com/Alexsandr_Kravstov
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