What Does THC Do to Dogs and Cats?
By Dr Duncan Houston
Quick Answer
THC affects dogs and cats by overstimulating the brain’s cannabinoid receptors, leading to neurological signs like disorientation, wobbling, sedation, and sometimes agitation or seizures. Pets are much more sensitive to THC than humans, so even small amounts can cause toxicity.
Dogs and cats don’t experience THC the way humans do.
What might seem like a mild effect for a person can hit a pet much harder… and much more dangerously.
Why pets react differently to THC
Pets have a higher concentration of cannabinoid receptors in their brain.
This means:
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stronger neurological effects
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longer duration of action
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increased risk of toxicity
Even small amounts can have a big impact.
Common signs of THC toxicity
Symptoms usually start within 30 minutes to a few hours.
You may see:
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wobbling or unsteady walking
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extreme sleepiness
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dilated pupils
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drooling
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urinary incontinence
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vomiting
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slow heart rate
Many pets appear disoriented or heavily sedated.
More serious signs
With higher exposure:
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agitation or anxiety
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vocalisation
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tremors
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seizures
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collapse
These cases require urgent veterinary care.
Why edibles are more dangerous
This is where things escalate quickly.
Edibles often contain:
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chocolate
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xylitol
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high fat content
So your pet may be dealing with multiple toxins at once, not just THC.
How long THC lasts in pets
THC stays in the system longer in pets than in humans.
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mild cases → 12 to 24 hours
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moderate to severe → up to 48–72 hours
Some pets may appear to improve, then worsen again as THC redistributes.
What to do if your pet ingests THC
If you suspect exposure:
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Contact your vet immediately
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Do not wait for symptoms
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Be honest about what was ingested
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Bring packaging if available
Early treatment significantly improves outcomes.
How vets treat THC toxicity
Treatment is usually supportive:
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monitoring
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intravenous fluids
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anti-nausea medication
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sedation if required
Most pets recover well with prompt care.
Final thoughts
THC is not safe for dogs or cats.
The biggest issue is not always the amount… it’s how sensitive pets are to it.
If there’s any chance your pet has been exposed, it’s always safer to act early rather than wait.
Still unsure what to do next?
THC exposure can be confusing, especially if your pet just seems “a bit off”.
Is it mild?
Will it pass?
Do you need to go to the vet?
If you’re unsure, getting guidance early can help you avoid missing something serious.
The ASK A VET™ app gives you access to veterinary advice when you need it, helping you act quickly and confidently in situations like this.
This article is general veterinary education and does not diagnose or treat an individual animal. Always confirm medication names, doses and interactions with the veterinarian who knows your pet.
If your animal is struggling to breathe, collapsed, bleeding heavily, seizing, or has eaten something toxic, contact your vet or the nearest emergency clinic now.
Animal Poisons Helpline (AU) 1300 869 738 · Animal Poisons Helpline (NZ) 0800 869 738 · ASPCA Animal Poison Control (US) (888) 426-4435
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Ask A Vet articles are written by Dr Duncan Houston BVSc, a practising veterinarian, unless another author is named in the byline.
