Is Chocolate Toxic to Dogs? Doses by Type and Weight

By Tailwisp Editorial TeamUpdated October 17, 20263 min read

Chocolate is one of the most common causes of poisoning calls for dogs, especially around holidays. The problem is not the sugar or fat, though those can cause trouble too, but a compound called theobromine, along with caffeine.

Why chocolate is toxic

Cocoa contains methylxanthines, mainly theobromine and caffeine. Humans break these down quickly, but dogs metabolize them slowly, so they build up in the body and affect the heart, nervous system and kidneys. The amount of theobromine varies widely with the type of chocolate. See also caffeine toxicity.

Theobromine content by type

These are approximate figures, and products vary.

• White chocolate: negligible theobromine.
• Milk chocolate: low, roughly 1 to 2 milligrams per gram.
• Semi-sweet and dark chocolate: much higher, roughly 5 to 6 milligrams per gram or more.
• Baking and unsweetened chocolate: highest, roughly 14 to 16 milligrams per gram.
• Cocoa powder: very high, similar to or above baking chocolate.
• Cocoa mulch used in gardens can also be dangerous.

Dose thresholds

Veterinary references suggest that mild signs can occur at around 20 milligrams of theobromine per kilogram of body weight, more severe signs, including heart problems, at around 40 to 50 milligrams per kilogram, and seizures at around 60 milligrams per kilogram or more. These are guidelines, not safe limits, and individual dogs vary. A small dog can be seriously affected by a small bar of dark chocolate. Always call your vet or a poison helpline rather than calculating on your own.

Signs of chocolate poisoning

• Vomiting and diarrhea
• Increased thirst and urination
• Restlessness, hyperactivity, panting
• Fast or irregular heartbeat
• Muscle tremors
• Seizures
• Collapse

Signs usually appear within six to twelve hours and may last a day or more, because theobromine is cleared slowly.

What to do

1. Remove any remaining chocolate and check how much is missing.
2. Note the type of chocolate, the amount, the time eaten and your dog's weight. Keep the wrapper.
3. Call your vet, an emergency clinic or a pet poison helpline immediately.
4. Follow instructions. Your vet may induce vomiting, give activated charcoal, provide fluids and monitor the heart.
5. Do not make your dog vomit at home unless a professional tells you how.

See our guide to what to do if your dog is poisoned.

Treatment

Treatment depends on the dose and timing. It may include inducing vomiting if recent, giving activated charcoal to reduce absorption, intravenous fluids, medications for heart rhythm or seizures and monitoring. Early treatment gives the best outcome.

Hidden sources

• Chocolate-covered raisins, nuts and coffee beans, which add other toxins. See grapes and raisins and macadamia nuts
• Brownies, cakes and cookies
• Hot chocolate mix
• Some sugar-free products that also contain xylitol. See xylitol

Prevention

• Store chocolate in closed cupboards, not on tables or in bags.
• Warn guests and children, especially at holidays.
• Dispose of wrappers in sealed bins.
• Teach a solid "leave it" cue. See our recall and training guides.

A worked example of risk

Consider a ten-kilogram dog that eats thirty grams of dark chocolate containing about five milligrams of theobromine per gram. That is around 150 milligrams in total, or 15 milligrams per kilogram, which is below the level at which serious signs are expected, but mild signs are possible. The same dog eating thirty grams of baking chocolate with fifteen milligrams per gram would receive about 45 milligrams per kilogram, a dose that can cause severe signs. This is why you should always give the exact type and weight when you call.

Online calculators

Some veterinary organizations and poison helplines offer chocolate toxicity calculators. They can give a useful first estimate, but they are not a substitute for professional advice, particularly for puppies, seniors and dogs with heart or kidney disease. If in doubt, call.

Recovery and aftercare

After treatment, most dogs recover well, but some need to stay in hospital for monitoring. Offer a bland diet and fresh water once your vet agrees, and avoid giving more rich foods. Because theobromine can be recirculated in the body, signs can recur, so follow the discharge instructions carefully.

The takeaway

Chocolate is a genuine poison for dogs. Act quickly if your dog eats some, and call for professional advice instead of waiting.

This article is general educational information, not veterinary advice. Every dog is different. If your dog is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.