A: Many pet owners come to me with questions about dogs and chocolate. The topic is especially timely now, when Halloween candy is in so many homes across the US. During the holiday season in general vets see an increase in visits from owners whose dogs have ingested chocolate simply because there tends to be more of it lying around the house. The reason we see chocolate ingestion more in dog than cats is because dogs will often eat anything that smells good whereas cats are more picky.
Chocolate contains theobromine, an alkaloid of the cacao plant. Though the amount found in chocolate is safe for humans to ingest, theobromine is harmful to dogs because they metabolize this alkaloid more slowly than humans do. Not all chocolate contains the same amount of theobromine: milk chocolate contains less then semi-sweet chocolate, which contains less then baking chocolate.
A dog that has eaten chocolate may exhibit symptoms including (but not limited to) vomiting, diarrhea, hyperactivity, tremors, seizures, racing heart rhythm progressing to abnormal rhythms and, in severe cases, death. Other problems associated with chocolate ingestion include the high fat content in some chocolate products, and pancreatitis, which can also be seen post-ingestion.
If you know or suspect that your dog has eaten a piece of chocolate, contact your veterinarian. If possible, make sure to describe the type of chocolate and amount consumed. Your veterinarian can perform a simple mathematical formula that will determine whether or not the amount your dog ingested is toxic and requires immediate veterinary care.
During the holiday season — especially Halloween — be sure to keep chocolate out of reach of your animals.