Cannabis (THC) toxicity in cats is happening more often in the UK as cannabis products become more accessible. Cats are sensitive to THC, although they’re less likely to ingest cannabis products than dogs are. But even exposure to small amounts can lead to symptoms, such as wobbliness, sedation, dilated pupils and changes in behaviour. All cats are vulnerable, but inquisitive kittens and playful adult cats are most at risk. Talk to a vet without delay if your cat has consumed or been exposed to a cannabis product.

Cannabis toxicity (marijuana poisoning, THC intoxication) happens when cats ingest or inhale products containing tetrahydrocannabinol (THC), the psychoactive chemical found in the leaves and flowers of the Cannabis plant. Edible cannabis products, such as gummies and cannabis ‘cakes’, are especially risky due to high concentrations of THC and the presence of additional toxins, such as chocolate or xylitol (an artificial sweetener). With supportive care, most cats will recover within 1–3 days, but severe cases and cats who've consumed products containing additional toxins will usually need veterinary hospital treatment.

What is cannabis (THC) toxicity in cats?

Cannabis toxicity in cats occurs when they are exposed to THC, the psychoactive chemical in marijuana.

Cannabis contains 2 chemical compounds:

• Tetrahydrocannabinol (THC): A psychoactive drug that acts on the brain to alter mood, thought processes and perception; a popular ‘recreational drug’ in the UK.

• Cannabidiol (CBD): A non-psychoactive chemical, widely used in the UK for people and pets to aid relaxation, relieve pain, reduce anxiety and improve sleep.

Hemp oil is extracted from the seeds of the Cannabis plant. Hemp oil doesn't contain CBD or THC.

Cats are exposed to cannabis toxicity by any of the following:

• Consuming edible products containing THC, such as brownies or gummies

• Consuming cannabis oils or drops

• Inhaling smoke when humans smoke marijuana in enclosed environments or poorly ventilated rooms

• Accessing discarded or poorly stored concentrates or vape cartridges which have a high potency THC content

• Grooming contaminated fur after exposure to smoke or plant material

Cats are sensitive to the effects of THC because cannabinoid receptors are widely distributed within your cat’s nervous system.

Symptoms can develop within half an hour and may worsen quickly, especially if your cat consumed a cannabis ‘food product’ or concentrate. Talk to a vet without delay. The sooner your cat receives treatment, the better the outlook for prompt recovery.

Symptoms of cannabis toxicity in cats

Signs usually begin between 30 minutes to several hours after exposure:

• Becoming wobbly or unsteady on their feet (ataxia)

• Appearing very sleepy or sedated

• Dilated pupils / glassy eyes

• Dribbling urine or incontinence

• Vomiting or drooling

• Becoming oversensitive to sound or touch

• Trembling or twitching

• Low body temperature

• Becoming agitated, restless or vocalising

Severe cases may progress to collapse, seizures, difficulty breathing, and a coma.

Are some cats more at risk of cannabis toxicity than others?

All cats are susceptible to the effects of THC. However, some will have a relatively greater risk:

• Young and inquisitive cats: more likely to chew packaging or investigate discarded items

• Indoor cats in households where cannabis is used: greater risk of exposure

• Small or lightweight cats: higher risk from small doses

• Cats with heart disease or neurological problems: the action of THC may worsen clinical signs

• Households using edible cannabis products or concentrates: higher THC potency; risk of additional toxin exposure

• Outdoor cats in cities and towns are more likely to encounter discarded cannabis products

Safe treats for cats

How is cannabis toxicity diagnosed in cats?

Vets diagnose cannabis toxicity based on the history of possible exposure and your cat’s symptoms.

Your vet may also:

• Carry out a full physical and neurological exam

• Check any packaging for THC concentration or added toxins

• Run blood tests, including blood glucose

• Perform urine analysis

• Monitor your cat’s heart rate and blood pressure

Human drug tests for the presence of cannabis are unreliable in cats and often give false negative results.

What’s the treatment for cannabis toxicity in cats?

There’s no cure or antidote for THC toxicity. Treatment focuses on providing supportive care and controlling symptoms while your cat’s body removes the chemical and recovers. Mild cases may recover at home with careful monitoring, but moderate to severe cases require hospital care.

• Intravenous fluids (a ‘drip’)

• Anti-nausea medication

• Monitoring and controlling body temperature

• Sedation if symptoms include agitation

• Seizure control medication in severe cases

• Intravenous lipid emulsion (ILE) therapy for severe cases with life-threatening symptoms. ILE ‘draws’ THC out of tissues and into the bloodstream, where it’s carried to the liver for processing and removal.

• Oxygen therapy or ventilatory support (in rare, extreme cases)

Most cats make a full recovery within 24–72 hours.

How to look after a cat with cannabis toxicity at home

Always talk to a vet if you suspect your cat has been exposed to cannabis. Your vet may advise monitoring at home for mild cases. Even if your cat appears calm, they may be wobbly, disoriented and at risk of injury.

• Prevent further exposure: remove any cannabis products or contaminated materials

• Allow your cat to rest in a quiet, dimly lit room

• Block access to stairs or high surfaces to prevent falls

• Provide easy access to fresh water

• Offer small meals if fully alert

• Monitor breathing and responsiveness

• Never attempt to induce vomiting at home: risks of choking and aspiration pneumonia

Tips on how to prevent cannabis toxicity in cats

• Store cannabis products securely and out of reach

• Avoid leaving edible cannabis products unattended

• Remind guests to secure their belongings

• Avoid smoking or vaping around pets

• Dispose of waste safely

• Prevent access to discarded materials in outdoor areas

Is my family at risk of catching cannabis toxicity?

No. Cannabis toxicity is not contagious. However, safe storage is essential to protect children and pets.

• Store products in child-proof containers

• Avoid second-hand smoke exposure of any kind

• Keep rubbish bins secure

Common cannabis products in the home

CBD oil has become popular in products used for pain, anxiety and behavioural concerns in people and pets.

• Many CBD oil products are available ‘across-the-counter’ without a prescription.

• CBD oils sold legally should contain only trace amounts of THC.

• Pure CBD products are unlikely to cause severe toxicity, although mild drowsiness or appetite changes may occur.

• Symptoms of toxicity following CBD oil exposure may suggest higher-than-labelled THC levels.

• Talk to a vet without delay if you are concerned your cat shows symptoms of toxicity.

When you should be worried about cannabis toxicity in cats

Seek help from a vet immediately if your cat is:

• Unconscious or difficult to rouse

• Having seizures or tremors

• Having difficulty breathing

• Very weak or collapsed

• Suspected to have eaten a cannabis product also containing chocolate or xylitol 

• Vomiting repeatedly

• Getting worse as time goes on

Joii can help with:

• Advice following suspected ingestion without symptoms or with mild signs

• Home care following treatment

• Monitoring recovery

• Keeping your cat safe