Why is chocolate dangerous for dogs and cats?
Chocolate contains theobromine and a small amount of caffeine — two methylxanthines that dogs and cats metabolise very slowly. They build up in the bloodstream, overstimulate the heart and nervous system, and in high doses cause seizures or heart arrhythmia.
Cats are roughly 1.3× more sensitive to theobromine than dogs, and dark chocolate, baking chocolate and cocoa powder contain far more theobromine than milk or white chocolate.
About the dose levels
Reference dose bands for dogs: <15 mg/kg low risk · 15–25 mg/kg watch and call · 25–40 mg/kg see a vet now · >40 mg/kg emergency. Symptoms usually appear within 6–12 hours.
Reference dose bands for dogs: <15 mg/kg low risk · 15–25 mg/kg watch and call · 25–40 mg/kg see a vet now · >40 mg/kg emergency. Symptoms usually appear within 6–12 hours.
Signs to watch for
- Vomiting, diarrhoea, restlessness, hyperactivity
- Increased thirst, urination and panting
- Racing heart, tremors, muscle twitching
- Severe cases: seizures, collapse, heart arrhythmia
What to do right now
- Stay calm and record — the exact type of chocolate, amount, and your pet’s weight.
- Do NOT induce vomiting unless your vet tells you to.
- Call your vet or a poison line and keep the wrapper or box handy.
- Follow their advice — treatment may include decontamination, activated charcoal, IV fluids and monitoring.
If your pet shows any of the signs above, go to the nearest emergency vet now and call ahead.
For a dose worked out against your pet's weight, use the Chocolate Toxicity Calculator.