How Much Chocolate Is Toxic to Dogs? Chart by Weight
Short answer: mild signs start at about 20 mg of theobromine and caffeine per kg of body weight. For a 20 lb dog that is about 3 oz of milk chocolate, 1.1 oz of dark chocolate, or less than half an ounce of baking chocolate.
The toxic doses
Chocolate contains theobromine and caffeine (methylxanthines). The Merck Veterinary Manual gives these levels, in milligrams per kilogram of the dog's weight:
| Dose | What can happen |
|---|---|
| 20 mg/kg | Mild signs: vomiting, diarrhea, thirst, restlessness |
| 40-50 mg/kg | Heart effects: racing or irregular heartbeat |
| 60 mg/kg and more | Tremors and seizures; can be fatal |
The kind of chocolate matters most. Per ounce: milk chocolate about 64 mg, semisweet or dark about 160 mg, unsweetened baking chocolate about 450 mg, dry cocoa powder about 800 mg. White chocolate has almost none.
How much chocolate causes mild signs (20 mg/kg)
| Dog's weight | Milk chocolate | Dark / semisweet | Baking chocolate | Cocoa powder |
|---|---|---|---|---|
| 10 lb | 1.4 oz | 0.6 oz | 0.2 oz | 0.1 oz |
| 20 lb | 2.8 oz | 1.1 oz | 0.4 oz | 0.2 oz |
| 50 lb | 7.1 oz | 2.8 oz | 1.0 oz | 0.6 oz |
| 80 lb | 11.3 oz | 4.5 oz | 1.6 oz | 0.9 oz |
How much chocolate can cause seizures (60 mg/kg)
| Dog's weight | Milk chocolate | Dark / semisweet | Baking chocolate | Cocoa powder |
|---|---|---|---|---|
| 10 lb | 4.3 oz | 1.7 oz | 0.6 oz | 0.3 oz |
| 20 lb | 8.5 oz | 3.4 oz | 1.2 oz | 0.7 oz |
| 50 lb | 21.3 oz | 8.5 oz | 3.0 oz | 1.7 oz |
| 80 lb | 34 oz | 13.6 oz | 4.8 oz | 2.7 oz |
A regular milk chocolate bar is about 1.5 oz (43 g). So a 10 lb dog that eats one bar is at the mild level, while for an 80 lb dog it is a low dose. One ounce of baking chocolate is serious for a 20 lb dog.
Worked example
A 20 lb (9.1 kg) dog eats a 3.5 oz bar of 70% dark chocolate. Using 160 mg per ounce: 3.5 × 160 = 560 mg, and 560 ÷ 9.1 = 62 mg/kg. That is above the seizure level: this dog needs a vet now. (Very dark bars can contain more than this, so treat them as even more dangerous.)
What to do
- Find the wrapper: it tells you the type and the weight.
- Run the numbers in the calculator below, then call your vet or a poison hotline (ASPCA (888) 426-4435, Pet Poison Helpline (855) 764-7661) if the result is above low or you are not sure.
- Do not make your dog vomit at home unless told to. Signs usually start 6 to 12 hours after eating and can last up to 3 days.
Also check the label for raisins, macadamia nuts and xylitol, which are toxic on their own. See the can dogs eat it checker.
Source: Merck Veterinary Manual, "Chocolate Toxicosis in Animals" (methylxanthine content per ounce and toxic doses). Values are rounded; real chocolate varies by brand.
Try the dog chocolate toxicity calculator
Enter your own numbers below, or open the full dog chocolate toxicity calculator with the formula and more examples.
This guide is general information, not veterinary advice. Your pet may differ: ask your vet. Terms
Frequently asked questions
How much chocolate is toxic to a dog?
Mild signs can start at about 20 mg of theobromine and caffeine per kg of body weight, heart problems at 40 to 50 mg/kg, and seizures at 60 mg/kg. For a 20 lb dog, about 3 oz of milk chocolate or 1 oz of dark chocolate reaches the mild level.
Will a little bit of chocolate hurt my dog?
A small amount of milk chocolate usually only upsets the stomach of a medium or large dog. Dark chocolate, baking chocolate and cocoa powder are much stronger, and small dogs are at more risk, so check the dose with the calculator.
How long after eating chocolate will a dog show symptoms?
Usually 6 to 12 hours, and signs can last up to 72 hours.
Is dark chocolate worse for dogs than milk chocolate?
Yes. Dark chocolate has about two and a half times as much theobromine as milk chocolate, and baking chocolate about seven times as much.