If a cat eats marijuana, it will likely get noticeably sick but almost certainly survive. THC exposures carry a high morbidity rate in cats, meaning most exposed cats show obvious symptoms, but the mortality rate is extremely low. No lethal dose has even been established for cats because death from THC alone is so rare it would likely only result from secondary complications.
That said, a stoned cat can look alarming. Knowing what to expect, how long it lasts, and what actually warrants emergency care can save you a lot of panic.
Common Signs of THC Exposure in Cats
Whether a cat eats plant material, nibbles an edible, or inhales secondhand smoke, the symptoms are similar. You may notice inactivity or extreme lethargy, loss of coordination (wobbly walking, stumbling, falling over), dilated pupils, drooling, and urinary incontinence. Cats also become unusually sensitive to motion, sound, and touch, sometimes flinching or startling at stimuli they’d normally ignore. Some cats develop a raised or visible third eyelid, which can look especially unsettling if you’ve never seen it before. Mild gastrointestinal signs like vomiting are also possible, along with a drop in body temperature.
In a study where cats were given a controlled dose of THC oil (41.5 mg/kg), the animals showed lethargy, mild GI upset, hypothermia, loss of coordination, and elevated third eyelids. All of them recovered without any treatment.
Why Edibles Are More Dangerous Than Plant Material
Marijuana edibles made for people are prepared with butter or oil specifically designed to extract and concentrate THC. This means a single brownie or gummy can contain far more THC than an equivalent weight of dried flower. If your cat ate an edible rather than a leaf or bud, expect stronger symptoms and a longer recovery. The additional ingredients in edibles, particularly chocolate, xylitol (a sugar substitute), or high amounts of fat, can pose their own separate risks. Chocolate toxicity or pancreatitis from a high-fat edible can be more medically serious than the THC itself.
How Quickly Symptoms Appear and How Long They Last
Symptoms from eating marijuana typically show up within 30 minutes to a few hours, depending on how much the cat ate and whether its stomach was full. Inhaled THC from secondhand smoke acts faster, sometimes within minutes, though the dose is usually lower. Most cats return to normal within 12 to 24 hours, though heavier exposures, especially from concentrated edibles, can produce symptoms lasting up to 72 hours. During this time your cat may seem disoriented, refuse food, or sleep far more than usual.
Secondhand Smoke Counts Too
You don’t have to catch your cat chewing on a stash for it to be affected. Secondhand marijuana smoke can produce the same set of symptoms: incoordination, dilated pupils, drooling, lethargy, and sensitivity to stimulation. Cats are smaller than most adult humans and have a faster respiratory rate, so they take in a proportionally larger dose of THC from smoke-filled air. If you smoke indoors and your cat starts acting oddly, the smoke is a likely explanation.
What Happens at the Vet
Veterinary treatment for THC exposure is supportive, meaning there’s no antidote. The vet manages symptoms while your cat’s body processes the THC on its own. That typically involves IV fluids to prevent dehydration, temperature regulation if the cat’s body heat has dropped, and anti-nausea medication if vomiting is severe. If the ingestion was very recent (within the last hour or so), the vet may induce vomiting or give activated charcoal to reduce absorption, though this works best before symptoms have started.
For the visit to be most helpful, be honest about what your cat got into. Vets aren’t there to judge your habits, and knowing the substance saves time and money by ruling out other toxins that look similar but require very different treatment. Symptoms of THC exposure overlap with those of antifreeze poisoning, certain pesticides, and other neurological emergencies. A straightforward answer can prevent unnecessary and expensive testing.
When the Situation Is More Serious
While THC itself is unlikely to kill your cat, a few scenarios raise the stakes. If your cat ate a chocolate edible, the combination of THC and theobromine (the compound in chocolate that’s toxic to pets) creates two overlapping poisonings. If the edible contained xylitol, that sweetener can cause a dangerous drop in blood sugar and liver damage in animals. Extremely young kittens, elderly cats, or cats with existing heart or liver conditions are also at higher risk of complications from any toxic exposure.
Signs that warrant an immediate vet visit include seizures, extreme unresponsiveness (not just sleepiness but inability to be roused), repeated vomiting, or a very slow heart rate. A cat that’s mildly wobbly and sleepy is having a bad time but is likely to ride it out. A cat that’s seizing, completely limp, or vomiting nonstop needs professional care quickly.
Keeping Your Cat Safe
Cats are curious and often attracted to plant material, so dried flower left on a table is fair game. Edibles that smell like food are even more tempting. Store all cannabis products in sealed, cat-proof containers, ideally in a closed cabinet. If you smoke or vape indoors, keep your cat in a well-ventilated separate room. Concentrates, vape cartridges, and THC-infused oils are especially risky because even a small lick delivers a high dose relative to a cat’s body weight.
The rising popularity of THC edibles has correlated with a sharp increase in pet poisoning cases reported to veterinary toxicology hotlines. Most of those cases end with a full recovery, but avoiding the exposure altogether is simpler, cheaper, and far less stressful for both you and your cat.