If your dog has just eaten chocolate, don’t wait for symptoms. Call your vet, an emergency vet clinic or the Animal Poisons Helpline on 1300 869 738. The helpline is a free service for Australian pet owners, and its website lists it as available 24/7. If you can’t get through, go straight to your vet or nearest emergency vet.
Keep the wrapper handy if you can, because they’ll want to know what kind of chocolate it was, roughly how much was eaten, when it happened and how much your dog weighs. Don’t make your dog vomit unless a vet or the helpline tells you to.
So why is chocolate bad for dogs? It’s one of the most common causes of poisoning in dogs, and the problem peaks every Easter. Over the 14 days around Easter 2024, the Animal Poisons Helpline recorded a 94 per cent increase in calls about pets eating chocolate compared with the rest of the year. Ninety-three per cent of those calls involved dogs, with Labradors the most common breed, as RSPCA WA reported. The answer comes down to two chemicals that dogs struggle to get rid of.
Why chocolate is toxic to dogs
Chocolate contains two substances that are toxic to dogs: theobromine and caffeine. Both belong to a group of stimulants called methylxanthines, which act on the nervous system, the heart and the muscles.
The biggest problem is that dogs process theobromine far more slowly than people do. According to McGill University’s Office for Science and Society, dogs don’t reach peak levels of theobromine in the blood until about 10 hours after eating it, and take around 17.5 hours to clear half of it. That gives it plenty of time to build up and cause harm, which can range from an upset stomach to serious problems with the heart and nervous system.
Which chocolate is most dangerous?
Not all chocolate contains the same amount of theobromine. Generally, the more cocoa a product contains, the greater the risk. Cocoa powder and unsweetened baking chocolate are the most dangerous, followed by dark and semisweet chocolate, then milk chocolate. White chocolate contains very little theobromine, according to Washington State University’s veterinary hospital, but that doesn’t make it a good treat: its fat and sugar can still upset a dog’s stomach.
The real risk depends on the type of chocolate, how much was eaten and the size of the dog, which is why there’s no single “safe” amount. As a rough guide, RSPCA WA’s lead vet, Dr Mairi Joyce, says just 50 grams of milk chocolate can be enough to poison a small dog, and the same amount of dark chocolate is even more toxic. An amount that barely affects a large dog can be serious for a small one. If you don’t know exactly how much was eaten, don’t try to work out the risk yourself. Keep the packaging and call for advice.
Signs of chocolate poisoning
A dog can seem completely normal right after eating chocolate. Signs can include vomiting, diarrhoea, restlessness, increased thirst and urination, hyperactivity, a racing heart and trembling. In severe cases, there can be abnormal heart rhythms, seizures and even death.
These signs may take several hours to appear. Because theobromine stays in the body so long, the WSU veterinary hospital notes they can last 24 to 72 hours. A dog that looks fine an hour later isn’t necessarily out of danger, which is why the Animal Poisons Helpline asks owners to call even if their pet seems well.
What to do, and what the vet will do
The most useful thing you can do is gather the details a vet or poisons specialist needs: the wrapper or product name, a rough idea of how much is missing, when it happened, and your dog’s weight. Then call your vet, an emergency vet or the Animal Poisons Helpline on 1300 869 738. As its emergency instructions explain, the helpline will assess the exposure and tell you whether your dog needs to go to a vet straight away or can be watched at home.
If a vet does need to treat your dog, what they do depends on the type and amount of chocolate, how long ago it was eaten and whether your dog is showing signs. If the timing is right, they may make your dog vomit under controlled conditions. RSPCA Victoria says vets can usually treat chocolate poisoning this way, along with supportive care, as long as they act quickly.
Other treatment can include activated charcoal, intravenous fluids, medication to control heart rhythm or seizures, and monitoring. None of this is something to improvise at home. Dogs that are treated promptly typically recover fully, according to the WSU veterinary hospital.
Check for sugar-free chocolate
If your dog has eaten a sugar-free chocolate product, check the ingredients. Some are sweetened with xylitol, which is highly toxic to dogs in its own right. RSPCA WA warns it can cause a life-threatening drop in blood sugar as well as liver failure. Tell the vet or helpline exactly which product it was.
Easter isn’t the only danger time
Chocolate is easiest for dogs to find at Easter, when there are suddenly baskets of eggs and chocolate bunnies around the house. RSPCA WA notes that pets often find hidden eggs before the children do. But the same thing can happen at Christmas, at a birthday party or whenever a chocolate bar is left on the bench, and dogs are remarkably good at finding food they shouldn’t have.
Chocolate isn’t the only risk, either. RSPCA WA’s 2026 Easter warning notes that the raisins, currants and sultanas in hot cross buns can cause kidney failure in dogs, and that the Animal Poisons Helpline sees a significant increase in calls about chocolate and sultanas every Easter. Fatty leftovers and cooked bones can cause serious problems too. The simplest protection is to keep chocolate and other risky foods well out of reach.
Don’t wait and see
Chocolate is dangerous to dogs because of theobromine and caffeine, which their bodies clear very slowly, and the darker the chocolate, the greater the risk. There’s no universal safe amount, so if your dog has eaten some, find the wrapper and make the call rather than waiting for symptoms. A few minutes on the phone could make all the difference.
A quick note: I’m not a vet, and this is a general explainer rather than advice for your pet. When it comes to your dog’s health, your vet is the health professional to call. If your pet has eaten chocolate or anything else that may be toxic, contact your vet, your nearest emergency vet or the Animal Poisons Helpline on 1300 869 738 straight away.
The way bodies keep their internal chemistry in balance is something I explore in what is homeostasis?, and for another animal story where the details matter, see my post on pizzly bears.
Sources
- Animal Poisons Helpline: About us
- Animal Poisons Helpline: Emergency instructions
- RSPCA WA: Dogs, cats and even pademelon at risk of choc horror (April 2025)
- RSPCA WA: Easter choc shock for worried pet owners (April 2026)
- RSPCA Victoria: Easter chocolate a big pet hazard
- McGill University Office for Science and Society: Why is chocolate poisonous to dogs?
- Washington State University Veterinary Teaching Hospital: Chocolate toxicity in dogs