Chocolate Toxicity - What Makes Chocolate Toxic To Dogs?

Good for humans, not for pets

Chunks of chocolate
Chunks of chocolate. © Getty Images / Mark Weiss

All About Chocolate Toxicity > What makes chocolate toxic

Animals often have a "sweet tooth" too
While recent studies have shown that chocolate may be beneficial for human health, it is important to know that chocolate can be toxic, and sometimes even fatal, for animals.

Dogs are most commonly affected, due to their ability to find it and the common 'sweet tooth' they seem to have. It is important to remember that cats and other species are susceptible to the toxic effects of chocolate, too.

What makes chocolate toxic, anyway?
Chocolate is made from the fruit (beans) of the cacao tree. Theobromine, a component of chocolate, is a toxic compound in chocolate. Caffeine is also present in chocolate and a toxic component, but in much smaller amounts than Theobromine. Both Theobromine and Caffeine are members of a drug class called Methylxanines.

Theobromine and caffeine effects on the body:

  • Central Nervous System (CNS) stimulant
  • Cardiovascular stimulant
  • Increase blood pressure (mild)
  • Nausea and vomiting

Why isn't chocolate toxic to humans?
Humans can break down and excrete Theobromine much more efficiently than dogs. The half life of Theobromine in the dog is long; approximately 17.5 hours.

Are some chocolates more toxic than others?
Yes. Unsweetened (baker's) chocolate contains 8-10 times the amount of Theobromine as milk chocolate. Semi-sweet chocolate falls roughly in between the two for Theobromine content.

White chocolate contains Theobromine, but in such small amounts that Theobromine poisoning is unlikely. Caffeine is present in chocolate, but less than Theobromine.

Quick Guide for Theobromine levels in different types of chocolate:
From The Merck Veterinary Manual, here are approximate Theobromine levels of different types of chocolate:

  • Dry cocoa powder = 800 mg/oz
  • Unsweetened (Baker's) chocolate = 450 mg/oz
  • Cocoa bean mulch = 255 mg/oz
  • semisweet chocolate and sweet dark chocolate is = 150-160 mg/oz
  • Milk chocolate = 44-64 mg Theobromine per oz chocolate
  • White chocolate contains an insignificant source of methylxanthines.

Source: Merck Veterinary Manual Online

All About Chocolate Toxicity > What makes chocolate toxic

Text: Copyright © Janet Tobiassen Crosby. All rights reserved.