dogs eating chocolate poisonous

By Andrew Fischer

Can dogs die if they eat chocolate?

Chocolate can be lethal to dogs. Our four-legged friends cannot digest certain chemicals contained in chocolate. These chemicals are called methylxanthines. Caffeine and theobromine are both methylxanthines and both are poisonous to dogs. 

Symptoms of chocolate poisoning in dogs include diarrhea, vomiting, general weakness, hyperactivity, anxiety, restlessness, rapid heartbeat, rapid breathing, tremors, seizures etc.

You should always contact your veterinarian if your dog happens to get into chocolate.

Does it matter what chocolate my dog eats?

The darker the chocolate, the worse. There is simply more poisonous theobromine in dark chocolates.

.Just because your dog didn’t die from eating a few pieces of white or milk chocolate, it doesn’t mean that he won’t develop serious conditions if he gets a bite of baker’s chocolate or eats one spoon of cocoa powder. 

The most dangerous types of chocolate (with the highest methylxanthines content) are:

  1. Cocoa powder (the most dangerous)
  2. Baker’s chocolate
  3. Dark chocolate
  4. Semisweet chocolate
  5. Milk chocolate 
  6. White chocolate (the least dangerous)

While white and milk chocolate are low on the list, it’s still not recommended to offer it to your dogs. Even these chocolates are potentially poisonous to your dog and could cause them harm.

Also, the size of your dog has a huge effect on how poisonous chocolate can be to them. Large dogs like German Shepherds can ingest a few pieces of dark chocolate and suffer only mild symptoms of poisoning. However, the same amount can be lethal to a Chihuahua or a Pug. You still you shouldn’t purposely feed any chocolate to any dog of course!

Also, a small amount of chocolate may only cause very mild health issues (an upset stomach, vomiting, etc). Consumption of larger quantities of chocolate will have more serious consequences. For example the high content of poisonous methylxanthines in dark chocolate means that even a very small amount like 25 grams is enough to poison a large dog.

How to calculate the risk of chocolate overconsumption?

Every veterinarian will assess the risk differently based on various factors of your dog including their individual health, age, type of chocolate they ate, pills they take etc. 

That means that there is no specific and fast rule. It’s recommended you always contact your vet if your dog ate some chocolate. 

General guidelines to calculate the health risk:

First you need to find out what type of chocolate your dog ingested. The more cocoa the chocolate has, the higher the risk of poisoning.

Chocolate contains methylxanthines. These are alkaloids that can be found in high concentrations in tea, coffee, or chocolate. Dogs cannot digest these chemicals, which are therefore poisonous to them in bigger quantities. 

Cocoa powder contains around 800 mg of methylxanthines per ounce

99% dark chocolate contains around 400 mg of methylxanthines per ounce

80% dark chocolate contains around 320 mg of methylxanthines per ounce

50% dark chocolate contains around 200 mg of methylxanthines per ounce

40% of dark chocolate contains around 160 mg of methylxanthines per ounce

Milk chocolate contains around 70 mg of methylxanthines per ounce

White chocolate contains around 1 mg of methylxanthines per ounce

Once you found out the type of chocolate your dog ate, you can calculate the risk of poisoning, using the following form:

(Milligrams of methylxanthines per ounce (see above) X ounces of the chocolate eaten by your dog) / dog’s weight in kilograms = dose of methylxanthines ingested per kg of dog’s bodyweight

Once you calculated the dose of methylxanthines ingested by your dog you can compare it to the data below. If your dog consumed less than 20 mg of methylxanthines (per kg of his bodyweight), he is at a relatively low risk of developing serious conditions. If he consumed between 20-40 mg he is at moderate risk. If he consumed more than 40 mg per kg of bodyweight he is at high or very high risk. (1)

Based on the ASPCA (Animal Poison Control Center) a dose of 100 to 200 mg of methylxanthines per kilogram of dog’s bodyweight is a lethal dose. 

For the full list have a look at the following table: 

Less than 20 mg of methylxanthines per kg of dog’s bodyweight = lower risk, dogs may nevertheless vomit, have diarrhea

20-40 mg of methylxanthines per kg of bodyweight = moderate risk, dogs may seem hyperactive, pace, anxious etc.

40-60 mg of methylxanthines per kg of bodyweight = high risk, dogs may develop rapid heart rate, heart failure and other serious issues

More than 60 mg of methylxanthines per kg of bodyweight = very high risk, dogs often develop muscle tremors, seizures, heart failure and other serious conditions

More than 100 mg of methylxanthines per kg of bodyweight = lethal dose for many dogs

Why is chocolate poisonous to dogs?

Many people ask us “why can I eat chocolate and my dog can’t?”

Humans can much more quickly metabolize certain chemicals in chocolate. The same is not true for dogs. Dogs’ bodies are not efficient in breaking down methylxanthines (theobromine, caffeine) in chocolate. The more chocolate they eat, the more methylxanthines are built up in their body and the more negative effect chocolate (theobromine and caffeine contained in chocolate) has on them. 

So although humans can easily metabolize methylxanthines, dogs can’t. In dogs, the metabolization of methylxanthines is much slower. These dangerous chemicals therefore accumulate to toxic concentrations in their bodies.

What to do if your dog eats chocolate?

If you think your dog ate chocolate, don’t wait for symptoms to show up, because these can take up to 12 hours to arrive. Also, because the stimulants in chocolate can stay in your dog’s body for up to 3 days, an early treatment is always recommended. It will help your dog recover quicker and lower the treatment costs. Most dogs survive chocolate poisoning because of quick-acting owners.

It’s always recommended to contact your dog and tell him how much chocolate your dog ate, what kind of chocolate he ate and what size is your dog.

Typically, your dog will may vomit on his own. If not and if you cannot reach an emergency, you can also try giving your dog hydrogen peroxide to make him vomit. Usually a dosage of 1 tablespoon for every 20 pounds of dog’s weight (other recommendations are 1 ml of 3% hydrogen peroxide per pound of dog). You can try to mix the peroxide with some peanut butter or other tasty treat to get your dog to eat it. 

In case of theobromine poisoning you should try to induce vomiting within two hours after eating chocolate.

Veterinarians often use other methods like drugs (apomorphine), pumping your dog’s stomach or using charcoal to induce vomiting. 

Symptoms of chocolate poisoning in dogs

The toxicity of chocolate is due to methylxanthines and results in:

vomiting, diarrhea, hyperactivity, anxiety, pancreas inflammation = pancreatitis, abnormal/rapid heart rhythm, excessive thirst, muscle twitching, increased urination, seizures, muscle tremors, pace, excessive panting, etc.

Some of these symptoms, like the seizures, internal bleeding or the rapid heart rate can ultimately be fatal to your dog.

Even at quite low doses, chocolate can also cause the dog’s heat regulation system to stop working. This condition is called malignant hyperthermia and lead to overheating and cardiac arrest.

How to prevent chocolate poisoning in dogs

One of the basic rules is to avoid leaving chocolate laying carelessly around your house. Some dogs like to sniff around if their owners are not around and could easily find it and eat it. 

Avoid feeding chocolate to your dog, even if it’s just a tiny piece.