Lets start with why chocolate is toxic to pets and what can happen if a toxic dose of chocolate is ingested. The 2 main chemicals in chocolate that cause the symptoms we see in chocolate toxicity are theobromine and caffeine. Cocoa beans contain approximately 1.2% theobromine by weight so one ounce can contain about 0.3 grams of theobromine, and processed chocolate usually has smaller amounts. These chemicals are stimulants to the central nervous system. Our pets metabolize these slower than people and when large amounts are ingested they can cause an increase in blood pressure, irregular heart rhythms and possibly even death. After ingestion these pets can also experience vomiting, diarrhea, or seizures. Also the high levels of fat and sugar in these treats can lead to episodes of severe pancreatitis that can require hospitalized care. Many of these pets once they have ingested chocolate will need to be made to vomit to eliminate the chemicals but this can only be done within the first few hours after so the sooner a veterinarian is contacted the better for the outcome of the pet.
There are three main factors to consider when deciding if a toxic level of chocolate has been ingested: the percentage of cocoa in the chocolate, the size of the pet, and how much chocolate was eaten. Different types of chocolate contain differing levels of these chemicals and the amount is dependent on the percentage of cocoa in the chocolate. Unsweetened cocoa powder has the highest levels then baker’s chocolate, dark chocolate, and least is milk chocolate. White chocolate does not contain cocoa and so only posses a threat to pets in regards to pancreatitis. Baker’s chocolate when eaten at 1.3 grams per kilogram of the pets’ body weight can be sufficient to cause signs of toxicity. So for example, 0.4 ounces of bakers chocolate can be enough to produce symptoms in a 20 pound dog. When in doubt contact your veterinarian or Pet Poison Helpline to see if a poisonous amount of chocolate was ingested.
Then the next step is asking the question How much did they eat? Not sure? You should be able to look on the packaging of the chocolate for how many ounces (grams) of chocolate are in the product. If your still not sure here are some guide lines: a milk chocolate Hershey’s bar contains 1.5 oz (43g) of chocolate, a Toblerone bar contains 3.5 oz (100g) of chocolate, and a single Hershey’s kiss contains 0.2 oz (5.7g) of chocolate.