Can Dogs Eat Chocolate? Toxic Doses and What to Do

Why chocolate is toxic to dogs

Chocolate contains theobromine and a smaller amount of caffeine. Both belong to a group of stimulants called methylxanthines. They act on the brain, the heart and the muscles, and they make the body lose more water through the kidneys.

People clear theobromine quickly. Dogs do not. In dogs, it takes about 17 hours for the body to get rid of half of a dose, compared with a few hours in people. That is why signs can last a day or more, and in severe cases up to three days.

Chocolate is also rich in fat and sugar. Even when the theobromine dose is low, a large amount of chocolate can upset the stomach. In some dogs it can trigger pancreatitis, a painful inflammation of the pancreas. Our guide to pancreatitis in dogs explains the signs.

Dark vs milk chocolate

The darker and more bitter the chocolate, the more theobromine it contains. The Merck Veterinary Manual gives these approximate amounts of theobromine and caffeine combined.

• Cocoa powder: about 800 mg per ounce (28.5 mg per gram)
• Unsweetened baking chocolate: about 440 mg per ounce (15.5 mg per gram)
• Semisweet and dark chocolate: about 150 to 160 mg per ounce (5.3 to 5.6 mg per gram)
• Milk chocolate: about 64 mg per ounce (2.3 mg per gram)
• White chocolate: about 1 mg per ounce, a very small amount

Cocoa bean hulls, sold as garden mulch, contain about 255 mg per ounce. Real products vary. VCA gives a range of 130 to 450 mg of theobromine per ounce for dark and baking chocolate, so a bar with a high cocoa percentage can behave more like baking chocolate than like milk chocolate.

White chocolate carries very little theobromine. It is still high in fat and sugar, so a large amount can cause stomach upset.

How much chocolate is dangerous?

The risk depends on three things: the type of chocolate, the amount eaten and the size of your dog. The Merck Veterinary Manual gives these rough thresholds, measured as milligrams of theobromine and caffeine per kilogram of body weight.

• About 20 mg/kg (9 mg per pound): mild signs, such as vomiting, diarrhea and increased thirst
• 40 to 50 mg/kg (18 to 23 mg per pound): effects on the heart
• 60 mg/kg (27 mg per pound) or more: seizures become possible

Some dogs become severely ill at lower doses, so treat these numbers as a guide, not a safe limit.

As a worked example, a 22-pound (10 kg) dog could show mild signs after eating roughly the following.

• 3 ounces (about 87 grams) of milk chocolate
• 1.3 ounces (about 37 grams) of dark chocolate
• Under half an ounce (about 13 grams) of baking chocolate
• A quarter of an ounce (about 7 grams) of cocoa powder

The same dog could have seizures after about 9 ounces of milk chocolate or 4 ounces of dark chocolate. VCA gives a similar picture for a bigger dog: a 50-pound dog could show signs of poisoning after only about 1 ounce of dark or baking chocolate.

Online chocolate toxicity calculators, such as the one from Pet Poison Helpline, can give a rough estimate. They are a starting point, not a replacement for advice. Call your vet whenever you are unsure.

Signs of chocolate poisoning

Signs usually appear within 2 to 12 hours after the chocolate is eaten. Early signs include the following.

• Vomiting and diarrhea
• Drinking and urinating more than usual
• Restlessness, pacing, panting or hyperactivity
• A swollen or tender belly

As the dose rises, signs can progress to these.

• A fast or irregular heartbeat
• Muscle tremors, stiffness or a wobbly walk
• High body temperature and fast breathing
• Seizures
• Collapse or coma

Many dogs that eat a small amount have mild signs or none. That is not a reason to wait and see. Theobromine is absorbed slowly, so a dog that seems fine an hour after eating dark chocolate can become ill later.

What to do if your dog eats chocolate

Act quickly, even if your dog seems normal.

• Move your dog away from any remaining chocolate, and keep the wrappers.
• Work out what type of chocolate it was, how much is missing and roughly when it was eaten.
• Note your dog's weight, from the scales or the last vet visit.
• Call your vet, an emergency clinic or a pet poison helpline straight away. In the US, the ASPCA Animal Poison Control Center (888-426-4435) and Pet Poison Helpline (855-764-7661) can advise. Poison helplines may charge a consultation fee.
• If your dog already has signs such as vomiting, tremors, a racing heart or weakness, go straight to the nearest vet.

Do not try to make your dog vomit at home unless a vet tells you to. Vomiting is not safe for every dog, and some breeds and dogs with certain health problems are at higher risk of inhaling vomit into the lungs. Never use salt, mustard or syrup of ipecac. Salt can cause salt poisoning and swelling of the brain.

Read the label as well. Some chocolate products contain xylitol, a sweetener that can cause dangerously low blood sugar and liver injury in dogs. Raisins and macadamia nuts, common in chocolate bars and cakes, can also be toxic. Tell your vet about every ingredient. If your dog may have swallowed foil or plastic wrappers, mention that too, and see our guide to swallowed objects in dogs.

When it is an emergency

Go to a vet or an emergency clinic right away if your dog has eaten chocolate and you notice any of these signs or situations.

• Repeated vomiting or diarrhea
• Restlessness, pacing or panting that will not settle
• A racing or irregular heartbeat
• Tremors, twitching, stiffness or a wobbly walk
• Seizures
• Collapse, weakness or unusual drowsiness
• Any amount of baking chocolate, cocoa powder or cocoa mulch eaten by a small dog
• Chocolate that also contained xylitol, raisins or macadamia nuts

How vets treat chocolate poisoning

Treatment aims to remove as much chocolate as possible and to support your dog while the body clears the theobromine. If the chocolate was eaten recently, usually within about two hours, and your dog has no signs yet, the vet may give an injection or eye drops that make your dog vomit. Because chocolate is absorbed slowly, vets sometimes still induce vomiting several hours later. Activated charcoal may be given by mouth to limit further absorption.

A dog with signs often needs a stay in hospital. Care may include intravenous fluids, medicines to stop vomiting, control tremors or seizures and steady the heart rhythm, and close checks of heart rate, blood pressure and temperature. Some dogs need a urinary catheter or frequent walks to keep the bladder empty, which helps the body get rid of the toxin.

Dogs that ate a small amount or have mild signs usually do well with prompt treatment. The outlook is more guarded for dogs that have seizures or collapse, and delays make things worse.

Halloween, Christmas and other holidays

Chocolate poisoning follows the calendar. A University of Liverpool study of UK vet records found a clear peak in cases at Christmas and a smaller one at Easter. Peaks around Halloween and Valentine's Day have been reported in the US and Germany. Common culprits in the UK study included selection boxes, chocolate cake, liqueurs, chocolate Santas and advent calendars.

• Keep Halloween candy bowls and trick-or-treat bags up high or behind closed doors.
• Do not hang chocolate decorations on the tree, and keep wrapped chocolate gifts off the floor.
• Store advent calendars out of reach.
• Ask guests and children not to share sweets with your dog, and pick up dropped treats quickly.
• Keep baking chocolate and cocoa powder in a closed cupboard.
• Give your dog a dog-safe chew during celebrations instead.

Holidays bring other risks too, from fatty leftovers to decorations and fireworks. See holiday dangers for dogs and cats and our list of common household poisons.

What about cats?

Cats are sensitive to theobromine too. They rarely eat chocolate, and poison centers receive few calls about cats. The same rule applies: if your cat eats chocolate, call your vet.

Rescue dogs and scavenging

Dogs that once lived on the street had to find their own food, and some keep the habit of grabbing anything edible within reach. At Paw Squadron, every rescued dog sees a vet and is dewormed soon after rescue, but good habits at home are up to the people who adopt them. Whether your dog came from a rescue or a breeder, keeping chocolate out of reach is a small step that can prevent a frightening night at the emergency clinic.

For more guides on keeping your dog safe at home, browse PawPedia. If you adopted from us and have a question, write to us from the Contact page.