Why
Chocolate contains theobromine and caffeine (methylxanthines), which dogs and cats break down far more slowly than people, so they overstimulate the heart and nervous system. The more cocoa, the more dangerous: baking chocolate, dark chocolate and cocoa powder are much riskier than milk chocolate. Cats can't taste sweetness, so they eat it less often, but they are just as sensitive to the toxins.
How to give it / if eaten
Call your vet, an emergency clinic or an animal poison control line right away, even if your pet seems fine. Note the time, roughly how much was eaten, and keep the wrapper (the cocoa percentage matters for the risk assessment). Don't try to make your pet vomit at home unless a vet tells you to.
Watch for these signs
Usually within 6โ12 hours: vomiting, diarrhea, excessive thirst and urination, restlessness or hyperactivity, and a racing heart. Severe cases can progress to muscle tremors, wobbliness and seizures.
FAQ
My dog ate one piece of chocolate. Will it be okay?
The risk depends heavily on the type of chocolate, the amount and your pet's weight, so it's hard to judge at home. For a small dog, a cat or dark chocolate, even one piece can be a problem, so call your vet with the wrapper in hand.
Is white chocolate safe?
White chocolate has very little theobromine, but it's loaded with fat and sugar that can trigger vomiting, diarrhea or pancreatitis. It's not a safe treat, so check how much was eaten and ask your vet.
General information only. Weight, age and health conditions change how a pet reacts, so ask your vet if you are worried.