Estimate the theobromine and caffeine dose in mg/kg, against veterinary thresholds
Updated October 2026
If your dog ate chocolate, call your veterinarian, an emergency clinic, or the ASPCA Animal Poison Control Center at (888) 426-4435, open 24 hours a day, every day (a consultation fee may apply). Have the wrapper, the amount missing and your dog’s weight ready; the numbers this page calculates are exactly what they will ask for. Do not wait for signs: according to the Merck Veterinary Manual they usually start 6 to 12 hours after eating, and vets typically induce vomiting only when exposure was recent (within about 2 hours) and the dog is otherwise normal. Do not try to make your dog vomit at home unless a veterinarian tells you to.
Enter your dog’s weight, the type of chocolate and your best estimate of how much was eaten, in grams or ounces (a standard candy bar label lists its weight). If you are unsure, use the largest amount that could be missing. The result gives the total theobromine plus caffeine, the dose in mg per kg, where that falls against veterinary thresholds, and how much of the same chocolate would reach each threshold.
Dose = grams eaten × methylxanthine content per gram ÷ the dog’s weight in kg. For 50 g of dark chocolate at 5.3 to 5.6 mg/g: 50 × 5.3 = 265 mg and 50 × 5.6 = 280 mg; divided by 10 kg, that is 26.5 to 28.0 mg/kg. Darker chocolate carries far more: unsweetened baking chocolate has about 15.5 mg/g and cocoa powder 28.5, compared with 2.3 for milk chocolate.
| Type | mg per gram | Grams to reach 20 mg/kg in a 10 kg dog | Grams to reach 60 mg/kg in a 10 kg dog |
|---|---|---|---|
| Semisweet or sweet dark chocolate | 5.3–5.6 | 36 | 107 |
| Milk chocolate | 2.3 | 87 | 261 |
| Unsweetened baking chocolate | 15.5 | 13 | 39 |
| Cocoa powder | 28.5 | 7 | 21 |
| Cocoa bean hulls or cocoa mulch | 9.0 | 22 | 67 |
| White chocolate | 0.04 | over 5 kg | over 15 kg |
The Merck Veterinary Manual gives approximate dog thresholds for theobromine plus caffeine: about 20 mg/kg for mild signs (vomiting, diarrhea, increased thirst), about 40-50 mg/kg for heart effects, and 60 mg/kg or more for seizures. The oral lethal dose for half of animals (LD50) is reported at 100-200 mg/kg, but the manual warns that severe signs and death may occur at much lower doses and that individual susceptibility varies. Signs can progress from restlessness and vomiting to hyperactivity, tremors, a racing or irregular heartbeat, high body temperature and seizures, and can last up to 72 hours in severe cases.
| Situation | Methylxanthines | Dose | Where it falls |
|---|---|---|---|
| 20 lb dog, 2 oz milk chocolate | 130 mg | 14.4 mg/kg | below the about 20 mg/kg level where mild signs are reported |
| 10 kg dog, 50 g dark chocolate | 265–280 mg | 26.5–28.0 mg/kg | mild-signs range (about 20 mg/kg and up) |
| 40 kg dog, one 1-oz square of baking chocolate | 439 mg | 11.0 mg/kg | below the about 20 mg/kg level where mild signs are reported |
| 5 kg dog, 2 tablespoons (about 10 g) of cocoa powder | 285 mg | 57.0 mg/kg | heart-effects range (about 40-50 mg/kg and up) |
Small amounts of baking chocolate or cocoa powder can matter more than a whole milk chocolate bar. In a German review of 156 dogs seen after eating chocolate, 44 had signs, most often after dark or bitter chocolate, and 43 of those 44 survived with decontamination and treatment (Weingart and colleagues, 2021).
Cocoa mulch in gardens contains about 9 mg/g. Baking cocoa and brownie mix are far stronger than candy. Waiting for symptoms loses the window for decontamination. Assuming a big dog is safe: it depends on the dose per kg. Mixing up types: white chocolate has very little theobromine (0.04 mg/g), while baking chocolate has nearly 400 times as much.
It uses average cocoa content; actual products vary, and the Merck Veterinary Manual notes that individual susceptibility to methylxanthines varies. It does not cover xylitol, raisins, macadamia nuts or other ingredients mixed with chocolate, and it cannot tell you whether your dog is safe. Only your veterinarian or a poison control service can advise on treatment. Merck notes that chocolate poisoning is most common in dogs but many species are susceptible, so call about any pet that ate it.