Yes, marijuana is toxic to cats. THC, the psychoactive compound in cannabis, causes a range of symptoms in cats from lethargy and loss of coordination to vomiting, trembling, and urinary incontinence. Symptoms can appear as soon as 30 minutes after exposure and last up to 72 hours. Most cats recover with veterinary care, but they should not simply be left to “sleep it off.”
What THC Does to a Cat’s Body
Cats have the same type of cannabinoid receptors that humans do, but their smaller body size and different metabolism make them far more sensitive to THC. When a cat ingests or inhales THC, it affects their nervous system in ways they can’t understand or cope with. Unlike a person who chooses to get high, a cat experiencing THC toxicity is frightened, disoriented, and physically uncomfortable.
The most common signs reported to the Pet Poison Helpline between 2018 and 2023 were lethargy (30% of cases), loss of coordination (21%), and vomiting (15%). Other symptoms include urinary incontinence, heightened sensitivity to sound and motion, trembling, slow heart rate, agitation, dilated pupils, head bobbing, and drops in body temperature. In one study, cats given THC oil showed stomach upset, lethargy, hypothermia, poor coordination, and a visible raising of their third eyelids. Seizures, dangerously low blood pressure, and difficulty breathing are rare but possible.
How Cats Get Exposed
The most common route is eating something they shouldn’t. Cats may nibble on cannabis flower left on a table, lick butter or oil infused with THC, or get into edibles. Edibles are especially risky because they often contain high concentrations of THC in a form that smells appealing to a curious cat.
Secondhand smoke is also a real concern. Cats that breathe in marijuana smoke can develop the same symptoms as cats that eat cannabis directly: incoordination, dilated pupils, drooling, sensitivity to touch and sound, and incontinence. If you smoke or vape cannabis indoors, your cat is being exposed. Keeping the room ventilated or smoking in a separate, closed space your cat can’t access makes a meaningful difference.
Edibles Carry Extra Risks
Beyond the THC itself, cannabis edibles often contain ingredients that are independently dangerous to cats. Chocolate, xylitol (a sugar substitute), raisins, and high-fat foods can all cause additional poisoning or trigger conditions like pancreatitis. If your cat eats an edible, the THC is only one part of the problem. The other ingredients may require separate treatment.
CBD Is a Different Story
CBD and THC come from the same plant, but they behave very differently in a cat’s body. CBD is non-psychoactive and does not produce the intoxication that THC does. A 26-week study gave healthy cats a THC-free CBD extract daily at a controlled dose and found no clinically significant changes in their bloodwork or organ function. The cats tolerated it well throughout the entire study period.
That said, many CBD products marketed for humans contain trace amounts of THC, and “trace” for a human can be significant for a 10-pound cat. If you’re considering CBD for a cat with anxiety or pain, the product needs to be specifically THC-free and ideally formulated for pets. This is not the same as sharing your own CBD oil or gummies.
What Happens at the Vet
There is no reliable quick test for THC in cats. Some vets try human urine drug screening kits, but these were designed to detect human metabolites. Cats break down THC into additional compounds that human tests don’t pick up, so a negative result doesn’t actually rule out exposure. THC can also bind to the glass or rubber in sample containers, further skewing results. Diagnosis is typically based on your cat’s symptoms and your honesty about what they may have gotten into.
Treatment is supportive. Your vet will focus on keeping your cat hydrated, maintaining their body temperature, managing nausea, and monitoring their heart rate and breathing until the THC works its way out of their system. There is no antidote for THC poisoning. The goal is to keep the cat safe and comfortable while their body processes the drug, which can take anywhere from several hours to three full days.
Be upfront with your vet about the exposure. They are not going to judge you or report you. They need accurate information to treat your cat effectively and to rule out other toxins that might require a completely different approach.
How to Keep Your Cat Safe
Cats are curious and opportunistic. They knock things off counters, chew on plants, and investigate anything with a strong smell. If you use cannabis in any form, treat it like you would medication or cleaning products.
- Store all cannabis products in sealed, cat-proof containers. Edibles, flower, oils, and vape cartridges should all be in closed drawers or cabinets.
- Never blow smoke toward a cat or hotbox a room with a cat inside. Secondhand smoke causes the same toxic effects as ingestion.
- Keep ashtrays and roach clips out of reach. Cats may chew on remnants out of curiosity.
- Don’t assume a small amount is harmless. Cats weigh a fraction of what you do, so even a tiny piece of an edible delivers a proportionally large dose of THC.
Most cats that receive veterinary care after THC exposure recover fully. The danger increases when exposure goes unnoticed, when the cat ate something containing chocolate or xylitol along with the THC, or when an owner waits too long hoping the cat will recover on its own.