Could eating chocolate kill your dog?

Dogs and theobromine are not a good combination. Image: Shutterstock/Warren Goldswain

Dogs and chocolate have generally been labelled as a bad combination, however the amount of chocolate needed to cause serious effects in canines may surprise dog owners.

Chocolate contains theobromine, a bitter chemical found in cocoa beans, which is tied to illnesses in dogs. It widens the blood vessels causing a decrease in blood pressure, and also acts as a diuretic and general cardiac stimulant. Humans are able to metabolise theobromine much more quickly than canines, which is why you rarely hear of human cases of death by chocolate.

The good news is that it takes, on average, a fairly large amount of theobromine to cause a toxic reaction in dogs. The amount of theobromine necessary to kill any member of the canine family is 300 milligrams per kilogram of body weight. This means that there will be an obvious difference in the safe consumption of chocolate between a Teacup Chihuahua — which weighs around three kilograms — compared to a Saint Bernard, which can weigh up to 90 kilograms.

With this in perspective, it would take about 900 milligrams of theobromine to bring a Chihuahua close to death, or nine medium-sized milk chocolate bars — not exactly an average dog’s diet.

Different types of chocolate have different quantities of theobromine — dark having higher quantities and white having less. However, it would still take five large (129 gram) 82 per cent cocoa extra dark chocolates to knock out your average Cocker Spaniel. Even so, chocolate is full of sugar and high amounts of butter that can lead to an upset stomach in dogs (and humans) so a daily dose of chocolate isn’t recommended, even if it isn’t fatal.