Assessed risk
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Dog chocolate toxicity calculator
Chocolate contains theobromine and caffeine. How dangerous an exposure is depends on the dose per kilogram of your dog, and on how concentrated the chocolate was. This works that out against the thresholds in the MSD Veterinary Manual, showing every step.
If your dog has eaten chocolate, do not wait for symptoms
Call your veterinarian or your nearest emergency animal clinic. Chocolate signs can be delayed, and the amount your dog ate matters more than how they look right now. This calculator is here to help you describe the exposure accurately when you call — not to replace the call.
The dose
— mg/kg
Show the arithmetic
Source: MSD Veterinary Manual, Chocolate Toxicosis in Animals (full review Sept 2024, updated Feb 2026).
What each dose means
These thresholds describe populations. The same source states that severe signs and death may occur well below them, and that individual susceptibility varies.
How chocolate poisoning works
The toxic principles are the methylxanthines theobromine and caffeine. Dogs metabolise them far more slowly than humans, so a quantity that would barely register in a person can seriously sicken a dog.
The dose thresholds
- ≈20 mg/kg — mild clinical signs: vomiting, diarrhoea, increased thirst.
- 40–50 mg/kg — cardiotoxic effects: restlessness, agitation, raised temperature, racing or irregular heart rate.
- ≥60 mg/kg — seizures are reported at and above this dose.
- 100–200 mg/kg — the reported oral LD50 of caffeine and theobromine in dogs.
The sentence that matters most. Of those figures MSD says: “severe clinical signs and death may occur at much lower doses, and individual susceptibility to methylxanthines varies.” A dose under 20 mg/kg lowers the probability of serious illness; it does not reduce it to zero.
Concentration matters more than quantity
Per ounce of methylxanthines:
| Source | mg per gram | mg per ounce |
|---|---|---|
| Cocoa powder | 28.5 | 807 |
| Unsweetened (baker's) chocolate | 15.5 | 440 |
| Semisweet / sweet dark chocolate | 5.3–5.6 | 150–160 |
| Milk chocolate | 2.3 | 64 |
| White chocolate | 0.04 | 1.1 |
An ounce of cocoa powder carries about twelve times the methylxanthines of an ounce of milk chocolate. This is the commonest reason an exposure is underestimated at home.
If the label gives a cocoa percentage
Enter it above and the calculator uses it instead of a generic category. MSD’s rule:
15.5 × (% cocoa ÷ 100) mg per gram. Their example — a 65% bar — works
out at about 10.1 mg/g, or 286 mg per ounce.
Signs to watch for
Earliest: vomiting, diarrhoea, increased thirst. As the dose rises: restlessness, agitation, panting, raised temperature, racing or irregular heartbeat, tremors, and in severe cases seizures. Signs can be delayed, so a dog that looks normal an hour later has not been cleared.
Frequently asked questions
My dog ate chocolate but seems fine. Should I still call?
Yes. Signs can be delayed, and the first one may be restlessness rather than anything obvious. The dose determines the risk, not how your dog looks an hour later.
Is white chocolate safe then?
It is a negligible source of methylxanthines, so not a theobromine risk. That is not the same as harmless — fat and sugar can cause vomiting and diarrhoea, and large amounts can trigger pancreatitis.
What if I do not know how much was eaten?
Assume the worst case. Estimate high, pick the most concentrated chocolate that could plausibly have been in the house, and tell the vet it is an estimate.
Is this a substitute for veterinary advice?
No. It is an educational calculator on published figures and cannot examine your dog. Always confirm with a veterinarian or poison control.
Sources
- MSD Veterinary Manual, Chocolate Toxicosis in Animals (reviewed Sept 2024, updated Feb 2026). By Cristine Hayes, DVM, ASPCA Animal Poison Control Center. msdvetmanual.com
- MSD Veterinary Manual, Xylitol Toxicosis in Dogs (reviewed Sept 2024). msdvetmanual.com
How these sources were chosen, and what this site does not do: about & methodology.
Educational use only. Not a veterinary service, and it cannot account for your dog’s health history or how much they actually ate. If you suspect a poisoning, contact your own veterinarian or the nearest 24-hour emergency clinic immediately. No emergency or poison control service is named here because we do not promote commercial services.