A cat chews on a marijuana plant.

Is Marijuana Toxic to Cats?

Recent legalization of marijuana for human medicinal treatment in various states across the country has increased marijuana (pot) exposure and toxicity in pets. The Pet Poison Helpline suggests that there has been a 450% increase in veterinary visits and calls to animal poison hotlines due to marijuana exposure and toxicity.

Marijuana refers to a tobacco product made from the cannabis plant of which there are two common species—cannabis indica and cannabis sativa. There are many compounds that can be extracted from the plant, each having different properties that can create a variety of effects when ingested, absorbed, or inhaled.

Of the over 80 cannabinoids, the two most commonly studied and used are tetrahydrocannabinol (THC) and cannabidiol, commonly referred to as “CBD.” THC is the active ingredient that causes the majority of toxicity signs in cats.

How Marijuana Affects Cats

Cats may be exposed to marijuana by ingestion of cigarettes or dried pot leaves. Products containing THC are becoming more common at dispensaries in a variety of forms, and can all cause marijuana toxicity in pets. There have also been reports of secondhand smoke causing intoxication.

When inhaled or ingested, THC enters the body and binds with neuroreceptors in the brain, including norepinephrine, serotonin, and acetylcholine. This binding alters normal neurotransmitter function.

The most common side effects in cats are:

The signs of exposure can begin anywhere from 5 minutes to 12 hours after exposure, with symptoms lasting anywhere from a half-hour to several days.

If your cat is showing symptoms of toxicity, or you believe that they may have ingested marijuana in some form, please call your veterinarian immediately.

Is THC Okay for Cats?

THC is readily stored in the body’s fat tissue, which includes the liver, brain, and kidneys. The liver metabolizes this THC, and much of it is excreted in feces and urine.

The good news is that marijuana exposure and ingestion are rarely deadly in cats and long-term complications are uncommon. Toxicity of marijuana is low for cats, requiring roughly 1.5 grams of marijuana per pound of body weight to be fatal. The most severe problems relating to marijuana exposure or ingestion in cats have been from high concentrations of medical-grade THC.

Treatment of Marijuana Ingestion in Cats

There is no antidote for marijuana, which means that the treatment of marijuana exposure usually involves trying to eliminate the drug from the system, treat secondary signs, and provide support until the drug is eliminated from the system. The process of recovery may take more than 24 hours.

Treatments may include: