Dog Chocolate Toxicity Calculator

How this calculator works

Chocolate's danger comes from methylxanthines, mainly theobromine plus some caffeine. The calculator multiplies the amount eaten by the methylxanthine content the Merck Veterinary Manual lists for that type of chocolate, then divides by your dog's weight to get a dose in mg per kg. It compares that dose with Merck's levels:

• About 20 mg/kg: mild signs may occur (vomiting, diarrhea, increased thirst).
• 40–50 mg/kg: effects on the heart.
• 60 mg/kg and above: seizures.

Merck adds that severe signs and death can happen at lower doses than the reported lethal range, and that sensitivity varies between dogs. Signs usually start 6–12 hours after eating. That's why a "low" result here is still a reason to call: your vet or a poison specialist can account for your dog's health, what else was in the treat, and how long ago it happened.

Other ingredients matter too

Chocolate treats often hide other hazards. Raisins can cause kidney failure, sugar-free products may contain xylitol (see our xylitol label guide), and macadamia nuts appear on the ASPCA's list of foods to avoid. Tell the vet everything on the label. Around Halloween, read our Halloween candy guide.

This tool is for information only and is not veterinary advice. It does not diagnose or rule out poisoning.