flipfact, flipfacts, flipscience, dogs, dog, chocolate, theobromine, chowchow
Sally Ann Thompson/vetstreet.com

“Dogs shouldn’t eat chocolate” is a well-known nugget of pet care wisdom, and with good reason. The popular sweet has a number of ingredients, including sugar, that can be dangerous to our furfriends. Chief among these, though, are two compounds found in chocolate’s primary component, cacao beans (Theobroma cacao, after the Greek words for god, theo, and food, broma). These two stimulants are theobromine and caffeine; many of us are familiar with the latter, so let’s focus on the former.

Understanding why theobromine is dangerous to dogs requires knowing exactly what it is. Theobromine and caffeine are both methylxanthines, a class of alkaloids that, among other things, can clear the respiratory airway and increase heart rate. Theobromine is like a mild stimulant to us; that’s why a bite from a chocolate bar perks you up.

Theobromine toxicity depends largely on dosage, and humans process theobromine better than dogs can. In fact, we can safely eat about 1,000 mg per kg of body weight. (For reference, a typical milk chocolate bar contains about 100 mg.) On the other hand, it’s deadly for dogs; mild toxic signs begin at roughly 20 mg/kg, becoming more severe at 40-50 mg/kg.

Effects of theobromine consumption on dogs include (but are not limited to) convulsions, nausea, internal bleeding, and even death. That’s why the ideal course of action when your dog eats chocolate is to see a vet ASAP.

Regardless, not all dogs are affected by theobromine equally, with smaller dogs at greater risk. Basically, a small dose for a 32-kg Chow Chow would be too much for a 4-kg Shih Tzu. Experts also suggest that a particular genetic variant in some dogs may enable them to properly metabolize theobromine.

The type of chocolate can make a difference, too. White chocolate has the least theobromine content, followed by milk chocolate. Dark chocolate and baking chocolate have the highest levels, though, so keep them away from your pet at all costs.

(Even humans can fall prey to the effects of too much theobromine, though. The National Hazardous Substances Database states that consuming 50-100 g of cocoa daily can result in sweating, trembling, and severe headaches, so keep your chocolate cravings in check!)

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  • http://www.capitalcommunitynews.com/PDF/108_RAG_0512.pdf
  • https://pubchem.ncbi.nlm.nih.gov/compound/5429
  • https://theconversation.com/why-cant-dogs-eat-chocolate-89374
  • https://www.mcgill.ca/oss/article/health/my-dog-ate-chocolate-and-he-was-fine-so-whats-big-deal
  • https://www.petmd.com/dog/nutrition/4-types-chocolate-and-how-they-impact-dogs
  • https://www.scientificamerican.com/article/fact-or-fiction-chocolate-is-poisonous-to-dogs/
  • https://www.wired.com/2013/02/the-poisonous-nature-of-chocolate/

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Author: Mikael Angelo Francisco

Bitten by the science writing bug, Mikael has years of writing and editorial experience under his belt. As the editor-in-chief of FlipScience, Mikael has sworn to help make science more fun and interesting for geeky readers and casual audiences alike.