Dog Chocolate Toxicity Calculator
See what the amount of chocolate your dog ate means for its weight, and who to call. When in doubt, call first and calculate second.
Your dog ate something? Call now. Do not wait for signs.
Contact your veterinarian or an emergency clinic right away, or a poison control center. Call even if your dog seems fine: some poisons take hours to show. Do not make your dog vomit unless a professional tells you to.
- ASPCA Animal Poison Control Center: (888) 426-4435
- Pet Poison Helpline: (855) 764-7661
- UK: Animal PoisonLine (UK, run by VPIS): 01202 509 000
- Elsewhere: call your own vet or the nearest out-of-hours emergency vet immediately.
All three hotlines are open 24 hours and charge a consultation fee. The US numbers are not free calls from the UK. The numbers were checked on the publishers' sites on November 8, 2026.
Enter your dog's weight and how much chocolate was eaten. Whatever the result says, call your vet or a poison hotline.
Not veterinary advice. This calculator reports the dose and the veterinary reference levels. It cannot tell you your dog is safe. Call a vet or poison hotline in every case. Read the full disclaimer.
How much methylxanthine is in chocolate
| Type | mg per gram |
|---|---|
| White chocolate | 0.04 |
| Milk chocolate | 2.3 |
| Semisweet or dark chocolate | 5.6 |
| Unsweetened baking chocolate | 15.5 |
| Cocoa powder | 28.5 |
Values are from the Merck Veterinary Manual. For semisweet and dark chocolate Merck gives 5.3 to 5.6 mg/g, and the calculator uses 5.6 to err on the side of caution. A bar that shows a cocoa percentage holds about 15.5 mg/g times that percentage: Merck's example is a 65 % bar at about 10.1 mg/g.
How much reaches each level, by dog weight
Grams of chocolate that reach 20 mg/kg (mild signs) and 40 mg/kg (heart effects) for a few dog weights. These are the levels at which signs are expected, not safe amounts: call earlier.
| Dog weight | Milk: 20 / 40 mg/kg | Dark: 20 / 40 mg/kg | Baking: 20 / 40 mg/kg |
|---|---|---|---|
| 10 lb (4.5 kg) | 39 g / 79 g | 16 g / 32 g | 6 g / 12 g |
| 25 lb (11.3 kg) | 99 g / 197 g | 40 g / 81 g | 15 g / 29 g |
| 50 lb (22.7 kg) | 197 g / 394 g | 81 g / 162 g | 29 g / 59 g |
| 75 lb (34.0 kg) | 296 g / 592 g | 121 g / 243 g | 44 g / 88 g |
Frequently asked questions
Dog ate chocolate: what do I do?
Call your veterinarian, an emergency clinic or a poison hotline now: the ASPCA Animal Poison Control Center at (888) 426-4435 or Pet Poison Helpline at (855) 764-7661. Have your dog's weight, the type of chocolate and the amount ready, and the time it was eaten. Signs of chocolate poisoning usually begin 6 to 12 hours after eating, so do not wait for them.
What makes chocolate toxic to dogs?
Theobromine and caffeine, which belong to a group called methylxanthines. The Merck Veterinary Manual says the half-life of theobromine in dogs is 17.5 hours, so the effects last. It reports mild signs (vomiting, diarrhea, thirst) at about 20 mg/kg, harmful effects on the heart at 40 to 50 mg/kg, and seizures from 60 mg/kg.
Is white chocolate safe?
White chocolate is a negligible source of methylxanthines, according to Merck, at 0.04 mg/g. It can still contain other ingredients such as raisins, nuts or xylitol, and a large amount of any fatty sweet is a problem. If your dog ate it, still call and ask.
What are the signs of chocolate poisoning?
Merck lists increased thirst, vomiting, diarrhea, a swollen belly and restlessness first. They can progress to hyperactivity, frequent urination, wobbling, stiffness, tremors and seizures, with fast or irregular heartbeat, fever and collapse in severe cases.
Why is a small dog in more danger from the same bar?
Because the dose is counted per kilogram of body weight. The same 50 g of dark chocolate is a much higher dose for a 5 kg dog than for a 30 kg dog.
What about cats and other pets?
This calculator uses dog data only. Methylxanthines are poisonous to other animals as well, so call your vet or a poison hotline about any pet that ate chocolate.
Sources
- Chocolate Toxicosis in Animals. Merck Veterinary Manual. Read 2026-11-08. Used for: Methylxanthine content of each chocolate type; dose levels for mild signs (20 mg/kg), cardiotoxic effects (40 to 50 mg/kg) and seizures (60 mg/kg and above).
Facts last checked against their sources on November 8, 2026. Read how the numbers are built on the sources and method page.