Dog Ate Chocolate – Symptoms, Toxicity, And What You Should Do

dog ate chocolate

If my dog ate chocolate I’d be doing some quick math to work out whether a visit to the veterinarian was in order. Chocolate can be toxic for dogs, but how high the risk is depends on the amount of candy they’ve eaten and how big they are.


If your dog has ingested a lot of chocolate, the best thing to do is speak to your veterinarian straight away, especially if your dog is small. If your dog is a larger breed and only ate a small amount of chocolate, it is most likely not a medical emergency. However, no matter your dog’s size, if they have eaten dark chocolate you need to speak to your vet straight away.

There are lots of factors to look at if your dog ate chocolate. As, not every instance is as urgent as the next. Let’s take a closer look at why this is.

My Dog Ate Chocolate – Differences in Situation

Whether or not a dog will have a reaction from eating chocolate depends on three things.

  • What type of chocolate your dog ate.
  • How much your dog ate.
  • The size of your dog.

How These Influence The Situation

If your adult Lab just ate a small square of milk chocolate, a cupcake with some chocolate icing, or a chocolate chip cookie, there is no need to panic. The chances are this is not a medical emergency. If your dog is small, or ate much more chocolate than that, you should take action. Don’t just ignore the fact that your dog scoffed a load of Hershey bars. There is a possibility that he or she could need medical attention within the next hour or so.

Why is Chocolate Bad for Dogs?

The main harmful element of chocolate is a chemical called theobromine. The chemical code of theobromine is C7H8N4O2. There are other ingredients in chocolate that are also not great for dogs, such as sugar. And in many types of chocolate, milk is a key component. But it is the chemical called theobromine that causes the most trouble.

Theobromine is a vasodilator. That means it widens your blood vessels. You might think that’s a good thing—improving blood flow—and in some cases, it can be. In the past, for example, theobromine has been used to treat high blood pressure in humans. But theobromine is also a diuretic (makes you pee more) and a heart stimulant. Unfortunately, in large enough quantities, it is harmful to almost any animal that consumes it.

The chances of getting theobromine poisoning or chocolate toxicosis depend partly on how quickly the theobromine is broken down by the body. And that is where the problem lies for our dogs.

Why Can’t Dogs Eat Chocolate?

Despite the presence of the chemical theobromine, most humans suffer no ill effects from eating chocolate. Most, but not all. Chocolate toxicity does occasionally occur in people who consume large enough quantities. But chocolate poisoning in dogs is far more common. The reason is that theobromine is broken down far more slowly by the canine body. This chemical can actually stay in your dog’s bloodstream for up to 20 hours.

What Happens if my Dog Ate Chocolate?

If a human eats anything with theobromine (coffee also contains this chemical) the quantity of theobromine ingested will be halved within 6 to 10 hours. So, for the most part, people can consume chocolate without severe side effects. But, if your dog ate chocolate today, it would take around 18 hours for theobromine levels to be halved. Because the dog metabolizes theobromine so slowly, the higher levels in the dog’s body can do more harm.

The theobromine in chocolate interferes with a dog’s heartbeat. This can cause potentially fatal disruptions or irregularities to his heart rate. It also stimulates the dog’s nervous system, causing a number of dangerous symptoms.

How Much Chocolate Can Dogs Eat Safely?

How much chocolate can a dog eat safely? It depends partly on how much that dog weighs. For example, if a 60 pound Labrador ate 6 oz of milk chocolate, the risk of illness is low. In smaller dogs, eating chocolate is more serious. The same quantity might well kill a dog weighing 15 lbs or less. Don’t let anyone give chocolate of any kind to small breed dogs or puppies of any breed.

Many people get away with feeding milk chocolate or milk chocolate products, in small to moderate quantities to big dogs. You probably know someone who regularly does this. But, it doesn’t mean that they should. Or that the dog doesn’t feel unwell afterward. They are just unlikely to end up at the vet’s office. The same is most definitely NOT true of dark chocolate. This is the scary part. Let’s find out more about fatal amounts and types of chocolate.

What is a Fatal Amount of Chocolate?

Looking again at our example above. Let’s take the same 60 lb Labrador. And the same 6 oz quantity chocolate, but this time of dark chocolate. Now you’re looking at a very different scenario. The consumption of more than a couple of ounces of dark chocolate by an adult Lab should always be considered to be a medical emergency. Severe illness (and possibly death) is one potential outcome.

But why is dark chocolate so bad? Well, the darker your chocolate, the higher the theobromine levels! So, dark chocolate is naturally the most dangerous for dogs. Milk chocolate could also be harmful, but usually in greater quantities than would be needed for dark chocolate.

White Chocolate

You may have heard that dogs can eat white chocolate without coming to any harm. And there is some truth in that rumor. White chocolate contains less theobromine than milk chocolate. And a dog needs to consume even more of it to become sick. However, it does still contain theobromine and high levels of sugar. So, it isn’t entirely safe. Especially for smaller dogs and puppies.

My Dog Ate Chocolate

Symptoms of Chocolate Poisoning

Early symptoms may vary from dog to dog. But most dogs will experience some common ones. Here are some common early symptoms of chocolate poisoning:

  • Increased thirst (theobromine is a diuretic)
  • Restlessness
  • Vomiting
  • Diarrhea

After that, if a sufficient quantity of theobromine has been consumed, things may get much worse. If a dog ate a lot of chocolate, he may lose control of his legs and collapse. He may also have a seizure, and if untreated may fall into a coma. Fatalities can and do occur.

My Dog Ate Chocolate – First Actions

You’ll need to head over to a dog chocolate calculator. The one we recommend is in pounds and ounces. Write down how much your dog weighs in lbs. Weigh him if you have no idea. Then, write down approximately how much chocolate your dog has eaten in ounces. Go to the dog chocolate calculator on the Vet Manual website. Enter the color of the chocolate your dog consumed, his body weight in lbs and the weight of the chocolate in ounces. The calculator will tell you whether or not your dog is at risk.

You should make sure to contact your vet immediately if:

  • The calculator says your dog could be at risk
  • Your dog is very young or in ill health
  • Your dog shows any concerning symptoms
My Dog Ate Chocolate

My Dog Ate Chocolate – What will the Veterinarian Do?

You may wonder: But what can the vet do if my dog ate chocolate already? Good question. To treat chocolate poisoning, vets will usually try to cause your dog to vomit (if he hasn’t already). They’ll also give activated charcoal. This helps prevent the poison from getting absorbed into the dog’s stomach. You should not try to make your dog vomit by yourself.

The Labrador Handbook by Pippa Mattinson(paid link)

Vets will then give fluids to counteract all the peeing caused by theobromine, and to avoid dehydration. Depending on how sick your dog has gotten, they may either treat the seizures or manage the diarrhea. It’s normal to be worried about your furry family member, but try to stay as calm as possible. If caught early enough, most dogs can recover from chocolate toxicity.

Other Products to be Wary Of

Remember that bars of chocolate are not the only source of theobromine. It is also found in garden mulches made from cocoa plant products. But the most dangerous quantities are in cooking chocolate and cocoa powder. If you own a dog—especially a small dog—then these products should be safely and securely stored. Just like you would keep any other dangerous chemical out of reach of small children and dogs.

The Labrador Site Founder

Pippa Mattinson is the best selling author of The Happy Puppy Handbook, the Labrador Handbook, Choosing The Perfect Puppy, and Total Recall.

She is also the founder of the Gundog Trust and the Dogsnet Online Training Program 

Pippa's online training courses were launched in 2019 and you can find the latest course dates on the Dogsnet website


  1. What about trace amounts of chocolate? For example, if an adult lab gets a human treat with a very small amount of milk chocolate in it, or licks a dessert plate that still has a tiny amount of chocolate, will the theobromine have adverse effects, or will he metabolize it without it causing any symptoms or distress at all?

    (In other words…recognizing that large amounts of chocolate are really dangerous, and smaller amounts can still cause illness, is there some threshold at which a small amount is not at all harmful?)