The other day at our Vancouver animal hospital, Grant Cumberbirch (the owner) came in with his German Shepherd, Luna. Unfortunately, Luna has just discovered the household’s secret stash of dark chocolate. As we gave Luna an injection to induce vomiting I thought that a blog about chocolate poisoning would be appropriate as we enter the chocolate giving season.
Why is chocolate so toxic to dogs? Chocolate is derived from the roasted seeds of Theobroma cacao which contains caffeine and theobromine. Together these two products cause a toxic effect in dogs. The more theobromine and caffeine that a cocoa product contains, the more poisonous it is to your dog. In general, cocoa powder contains about 800mg per ounce of theobromine and caffeine, unsweetened bakers’ chocolate contains about 340mg, semi-sweet or dark chocolate contains 160mg, and milk chocolate about 64mg per ounce.
Death can occur at doses as low as 100mg/kg of theobromine. To put it into perspective, 1 square of unsweetened baker’s chocolate or 1 Lindt (100g) dark chocolate bar, or 1 Cadbury (230g) Milk Chocolate bar can be lethal to a 5 kg dog. Even at half these doses, life threatening signs such as seizures and heart arrhythmias can be seen. Vomiting and diarrhea can be seen at ¼ of these doses.
Luna, a 30kg dog, had eaten a giant 14oz bar of dark chocolate. We calculated her ingestion of theobromine and caffeine to be about 70mg/kg. This was definitely in the range where if not treated right away we could have seen seizures and heart problems. Luckily for Luna her human parent happened to be well informed and he brought her into our Vancouver animal hospital within half an hour of ingesting the chocolate. She vomited most of the chocolate up before it had a chance to be digested and absorbed. We followed up by giving her 2 doses of activated charcoal 6 hours apart to absorb any residual chocolate in her stomach and put her on intravenous fluids. We also did some blood work and continued to monitor her very closely for the next 6 hours. Luna never developed signs of toxicity and went home that evening to her loving home. The chocolate bars were now out of Luna’s reach and safely tucked away in Grant’s kitchen cupboards.
Moral of the story? Dogs will eat anything and they have an excellent sense of smell making it fairly easy for them to find secret stashes of chocolate. If you have friends coming over with gifts this season make sure you ask them if it is chocolate before putting it under the tree as your dog will undoubtedly open it before Christmas. It does not take a lot of chocolate, especially baker’s or dark chocolate for toxicity to occur and the sooner you bring your dog in for treatment after ingesting chocolate the better the chance for a good outcome.
If your dog does get into chocolate please call us immediately with the type of chocolate and the approximate amount your dog ingested. We will do a quick calculation and let you know if you have to worry or not.