As a dog owner, you may already know that your dog shouldn’t eat chocolate.  But you may not know why chocolate should be avoided in dogs. Chocolate is toxins to dogs, but the size and weight of your dog determines the risk and impact it could have. Learn how much chocolate is toxic and which types are the most dangerous.  

What Makes Chocolate Toxic for Dogs?

Chocolate is toxic to dogs because it contains the compound theobromine as well as caffeine. Both of these compounds together produce a stimulant effect in your dog, altering the function of the central nervous system and resulting in dangerous heart arrhythmias.  Theobromine exists in chocolate at a concentration of between 3-10x that of caffeine, however, both of these compounds work together to produce the dangerous effects of chocolate in dogs.  Although dogs are perhaps the most visible group of animals that are affected by chocolate toxicity, there are in fact many animals that are susceptible to the effects of chocolate.  Because of dog’s close proximity to us, their willingness to eat nearly anything, and the prevalence of chocolate-based candy in our modern world, the toxicity of chocolate in dogs is the most visible and well-known.

Types of Chocolate and Toxicity

A number of factors can affect the toxicity of chocolate in dogs.  Foremost among these is the type of chocolate. Different types of chocolate have varying levels of theobromine in them.  The amount of theobromine present in a product depends on many factors, including how the chocolate was prepared, how much cocoa/cacao is used in it, and how many other fillers are present in the chocolate.  However, in general, there is some consistency across popular types of chocolate that can be used to assess how dangerous a specific chocolate product is to your dog. 

The most dangerous type of chocolate that is commonly found in households is cocoa powder.  Cocoa powder, used for baking, has the highest concentrations of theobromine and caffeine in it, making it especially dangerous for dogs as consumption of a small amount can result in acute chocolate toxicity.  Cocoa powder has a concentration of 28.5 mg/g of theobromine and caffeine.  Unsweetened baker’s chocolate is second highest, with a concentration of 16mg/g.  Semi-sweet and sweetened dark chocolate, such as that found in baking chocolate chips, contains between 5.4-5.7mg/g, and milk chocolate contains 2.3mg/g. To put these numbers in perspective, the median lethal dose of cholate in dogs is between 100-200mg per kg of body weight.  However, this doesn’t tell the entire story, as there exists a wide range of variability between dogs in regard to their sensitivity to chocolate toxicity.  Many dogs can have profoundly negative health outcomes, and even death, at much lower doses.  It should also be noted that white chocolate does not pose a very high risk of toxicity, as it does not contain the theobromines and caffeine found in other forms of chocolate.

Symptoms of Chocolate Poisoning

Chocolate poisoning is a serious health condition in dogs that can lead to a number of negative health outcomes and even death.  As such, owners should be mindful of the signs and symptoms of chocolate poisoning in dogs.  Expect to see clinical signs of chocolate toxicity anywhere between 6-12 hours after consumption of chocolate.  Because the half-life of theobromine is extremely long in dogs (17.5 hours), these effects can last up to 72 hours after consumption.  

• Hyperactivity
• Restlessness
• Vomiting
• Diarrhea
• Elevated or irregular heart rate
• Frequent urination
• Seizures
• Muscle spasms/shaking/tremors

As the chocolate toxicity progresses, the symptoms will generally worsen.  Because of this, it is incredibly important that if you think your dog has consumed chocolate recently you contact your veterinarian immediately.  Treatment for chocolate poisoning generally consists of pumping the stomach to remove the chocolate and then monitoring the dog for 24-48 hours to ensure that no complications have occurred.  Many of the symptoms, such as seizures, can be controlled through medication.  In general, many dogs that consume a small amount of chocolate, such as that found in a Hershey’s kiss, end up with only mild symptoms.  However, much of this depends on the weight of the dog, their sensitivity to chocolate toxicity, and the concentration of cocoa in the product consumed.