If your dog has just eaten chocolate, call your vet or a pet poison line now — US: ASPCA Animal Poison Control (888) 426-4435; UK: Animal PoisonLine 01202 509000 (fees may apply). Then use this calculator to understand how serious the amount could be.
Dog Chocolate Toxicity Calculator
Did your dog eat chocolate? Check how serious it could be.
Why chocolate is dangerous for dogs
Chocolate contains theobromine and caffeine (methylxanthines), which dogs break down very slowly. The darker and more bitter the chocolate, the more it contains: dry cocoa powder and baking chocolate are the most dangerous, milk chocolate much less, and white chocolate has almost none — though its fat can still cause stomach upset or pancreatitis.
According to the Merck Veterinary Manual, mild signs appear at about 20 mg per kg of body weight, heart effects at 40–50 mg/kg and seizures at 60 mg/kg or more. Signs usually start 6–12 hours after eating and can last for days.
Frequently asked questions
What are the signs of chocolate poisoning in dogs?
Vomiting, diarrhoea, thirst, restlessness, panting, a racing heart and, at high doses, tremors and seizures.
Is a small amount of milk chocolate OK?
A small piece of milk chocolate is unlikely to seriously harm a large dog, but it can for a small dog. Always call your vet — the calculator shows why size matters.
Can cats get chocolate poisoning?
Yes, although cats rarely eat it. The same substances are toxic to cats.