How much dark chocolate is dangerous?
The Merck Veterinary Manual gives a quick rule: multiply the cocoa percentage by 15.5 mg per gram. So a 70% bar has about 10.9 mg/g and an 85% bar about 13.2 mg/g. The calculator uses 75% as a middle value. If your bar is 90% or more, treat it like baker’s chocolate. Even a few squares of a strong dark bar can be dangerous for a small dog.
| Dog weight | Mild signs (20 mg/kg) | Heart effects (40 mg/kg) | Seizures (60 mg/kg) |
|---|---|---|---|
| 5 lb | 4 g | 8 g | 12 g |
| 10 lb | 8 g | 16 g | 23 g |
| 20 lb | 16 g | 1.1 oz | 1.7 oz |
| 40 lb | 1.1 oz | 2.2 oz | 3.3 oz |
| 60 lb | 1.7 oz | 3.3 oz | 5.0 oz |
| 80 lb | 2.2 oz | 4.4 oz | 6.6 oz |
What to do if your dog ate dark chocolate
Note the time and keep the wrapper. Then call your vet or ASPCA Animal Poison Control at (888) 426-4435. If it was eaten within the last 2 hours and the dose is significant, your vet will likely give a medicine that makes your dog vomit. That is far safer than trying it at home. Dogs that already have symptoms may need IV fluids, heart monitoring and medication to control tremors.
Frequently asked questions
How much dark chocolate is toxic to a dog?
Mild signs can start at about 20 mg/kg of methylxanthines. For dark chocolate that is about 16 g for a 20 lb dog and 1.7 oz for a 60 lb dog.
What are the symptoms of chocolate poisoning?
Vomiting, diarrhea, thirst, restlessness, panting, a racing heart, tremors and in severe cases seizures. They usually begin 6 to 12 hours after eating.