Coffee & Caffeine poisoning in dogs and cats
Toxic agent: Caffeine, a methylxanthine · Reviewed 2026-08-18
Phone a vet now, before reading on. Have ready: your pet's weight, roughly how much was eaten and when, and the packaging if there is any. ASPCA Animal Poison Control (+1 888 426 4435), Pet Poison Helpline, or Animal PoisonLine in the UK.
Coffee grounds, espresso beans, energy drinks and caffeine tablets are all the same problem, and caffeine hits harder and faster than the theobromine in chocolate.
What it actually does
Caffeine is the same class of compound as chocolate's theobromine but more potent and more rapidly absorbed. It blocks adenosine receptors, floods the system with catecholamines and drives heart rate and blood pressure up. Unlike chocolate, where the fat slows absorption, a lapped-up energy drink or wet grounds deliver the dose almost immediately.
How much matters
By source, roughly:
| Brewed coffee | 80–100 mg caffeine per cup |
|---|---|
| Espresso beans, eaten whole | about 6 mg per bean, and dogs eat handfuls |
| Energy drink | 80–300 mg per can, plus sugar and taurine |
| Caffeine or diet pills | 100–200 mg per tablet — the most concentrated household source |
| Clinical thresholds | signs from about 20 mg/kg, severe from about 60 mg/kg, life-threatening around 140 mg/kg |
Used coffee grounds in the bin are a common route and still contain plenty of caffeine. So do the paper filters.
What you will see, and when
Onset: 30 minutes to 2 hours. Typical course: 12 to 48 hours.
- 30–120 minutesRestlessness, pacing, vomiting, excessive thirst
- 2–6 hoursRacing heart, tremors, high blood pressure, hyperthermia
- 6+ hoursArrhythmias, seizures, muscle breakdown, collapse
What the vet will do
Decontamination, repeated activated charcoal, intravenous fluids, beta blockers for tachycardia and anticonvulsants as needed. Blood pressure and cardiac rhythm are monitored rather than checked once. No antidote.
Outlook
Good with prompt care. Caffeine tablets and diet pills produce the worst cases because the dose per gram is so high.
Dogs and cats are not the same here
Both, with cats more sensitive per kilogram. Cats are more likely to lap a milky coffee than eat beans.
Where it comes from in a normal house
- Coffee grounds, used or fresh, and the compost bin
- Chocolate-covered espresso beans — caffeine and theobromine together
- Energy drinks and pre-workout powders
- Caffeine, diet and stay-awake tablets
- Tea bags, including used ones
The thing people get wrong
“A lick of coffee from a mug is nothing.”
A lick usually is. The cases that reach a clinic are the bin of used grounds, the box of espresso beans and the dropped caffeine tablets — concentrated sources eaten in quantity, and absorbed fast.
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Get PawLife on the App StoreFrequently asked questions
How much Coffee & Caffeine is dangerous?
Used coffee grounds in the bin are a common route and still contain plenty of caffeine. So do the paper filters.
How long after exposure to Coffee & Caffeine do symptoms start?
30 minutes to 2 hours. Restlessness, pacing, vomiting, excessive thirst. 12 to 48 hours.
Is Coffee & Caffeine worse for cats or dogs?
Both, with cats more sensitive per kilogram. Cats are more likely to lap a milky coffee than eat beans.
Is it true that: A lick of coffee from a mug is nothing.
A lick usually is. The cases that reach a clinic are the bin of used grounds, the box of espresso beans and the dropped caffeine tablets — concentrated sources eaten in quantity, and absorbed fast.
Related emergencies
Sources
This page is information, not veterinary advice. Toxic doses vary with body weight, age, breed and individual sensitivity, and the figures above exist to explain what a vet is assessing, never to decide that an amount is safe. If you are reading this because something has already been eaten, call a vet.