This article is about chocolate toxicity in dogs. As with all toxicities, it is dose-dependent (how much is eaten), and variable in effect on an animal. Due to the difference in types of chocolate, there could be a dramatic effect or there could be no effect on a dog. In this discussion, I will go over what to watch for and what to do if you suspect a problem if your dog has eaten chocolate at home.

What makes chocolate toxic to a dog? The drug type is generally called methylxanthines, of which two of these can potentially have an effect. Theobromine and caffeine. are the substances that can cause toxicity when ingested. Various chocolate types have different levels of these chemicals in them. Cocoa powder has by far the most amount of theobromine in it, along with a moderate amount of caffeine. Baker’s chocolate is second in theobromine levels but has a higher amount of caffeine compared to cocoa powder. These two products are the most potentially dangerous to dogs, given their levels of chemicals in them; semisweet chocolate, instant cocoa mix powder, and milk chocolate all have a much lower amount of methylxanthines in them. White chocolate has a minimal amount of the potential toxin in it, making it very safe. A non-food product that can be toxic is unprocessed cocoa bean mulch, which can be high in theobromine and caffeine content.

The signs of chocolate toxicity may begin 6-12 hours after ingestion. Physically, the toxicity can affect the heart, GI tract, and nervous system. A dog may start drinking more water, have gastrointestinal upset such as diarrhea or vomiting, and become restless. Additional effects late may start later are tremors, urinating frequently, difficulty walking, seizures, collapse, or at its worst, a coma. The signs can be variable due to the amount and type of chocolate ingested. For example, if white chocolate is eaten, there is very little chance for toxicity to occur, due to the very low levels of theobromine and caffeine in it. On the other hand, if a decent amount of Baker’s chocolate is eaten, there will be a concern for a toxic reaction to happen. Keep in mind that the size of a dog can be a variable in a potential toxic effect because the dose is weight-dependent. Another consideration about chocolate is that it is high in sugar and fat, which can lead to gastrointestinal upset, or at worst, pancreatitis.

With all cases of potential toxicity, treating it promptly, and sometimes with precaution, will lead to the best outcome for the dog. If you know that your dog has eaten a chocolate product, please notify us. We could figure out if there is going to be a potential toxic effect, or if we will need to treat it as a precaution. Here are a couple of varying scenarios. For example, if your eighty-pound Golden Retriever has eaten one chocolate chip cookie, there should be little concern. If he has eaten 20 cookies, please let us know, we may have to intervene. Taco the Chihuahua has eaten 10 small dark chocolate Hershey bars, this should be addressed quickly. There will be more concern with small dogs because a smaller amount of chocolate can have a toxic effect. In my experience, diarrhea and/or vomiting are usually seen first, followed by anxiety or restlessness. These have been usually smaller dogs that have eaten a moderate to a large amount of chocolate. If we can treat by detoxification or inducing vomiting prior to toxic effects, the outcome will be better.

Try to keep the pooches away from this potential toxin! Again, if there are any questions or concerns about any known or potential ingestion, please let us know.

Dr. Jaime Kozelka
St. Francis Hospital for Animals