No Chocolate for Your Pets
November 15, 2010
An archive of Pet Columns from the University of Illinois College of Veterinary Medicine is available online at Requests for reprints of this article may be directed to Chris Beuoy,

For people, a chocolate bar can send our taste buds to heaven. But for dogs and cats, consuming even a little bit of chocolate could send them to the emergency room.

Dr. Sandra Yi, a veterinarian and assistant professor of toxicology at the University of Illinois College of Veterinary Medicine in Urbana, warns that chocolate can cause serious illness in pets because it contains theobromine and caffeine. Theobromine and caffeine are chemicals called methylated xanthine alkaloids. While not harmful in small amounts in humans, these compounds can be deadly in dogs and cats.

The compounds in chocolate are harmful to pets because they stimulate the sympathetic nervous system, commonly known as the "fight or flight" branch of the nervous system. Stimulation of the sympathetic nervous system causes the body to release a chemical called epinephrine (also commonly known as adrenaline), allowing humans and animals to have the ability to react in potentially harmful or emergency situations.

However, toxic doses of methylxanthines lead to the over-stimulation of this system, says Dr. Yi. As a result, a pet that ingests a harmful amount of methylxanthines may breathe rapidly and become very restless and overheated. A pet's heart rate and blood pressure may increase drastically, possibly culminating in cardiac arrhythmias (an abnormal heartbeat). They may also vomit, have diarrhea, and drink and urinate more than usual. Ingesting chocolate could ultimately lead to seizures or even death without appropriate veterinary care.

The symptoms that will occur in your pet will depend on several factors: the type of chocolate ingested, the amount ingested, the weight of your pet, and your pet's health history. The concentration of methylxanthines vary by the type of chocolate, ranging from the least in white chocolate up to the most in cocoa powder:

  • White chocolate
  • Milk chocolate
  • Dark chocolate
  • Instant cocoa mix
  • Semi-sweet chocolate
  • Baking chocolate
  • Cocoa beans (Note: cocoa bean mulch, a commercial product for gardens, is very harmful if ingested by pets.)
  • Cocoa powder

Of course, the more chocolate your pet ingests, the more likely you are to see significant symptoms. Also, the less your pet weighs, the more likely exposure will bring severe effects.

If your pet has ingested a toxic dose of chocolate, your veterinarian will recommend treatment options that take into consideration the amount and type of chocolate ingested as well as the health history of your pet. One option is to induce vomiting to remove some of the chocolate from your pet's stomach before it is digested; however, this can cause more problems for your pet if not done correctly, so it should not be done without instruction from a veterinarian.

If inducing vomiting is not an option or if it does not result in the recovery of enough chocolate, the veterinarian may also need to treat your animal with a substance called activated charcoal, which prevents the intestines from absorbing the methylxanthines. Treatment with intravenous fluids and medication to prevent seizures and the adverse effects on the heart may also be needed.

If you suspect that your pet may have ingested chocolate or another product that contains methylxanthines, it is better to err on the side of caution and treat the situation as if it were a worst-case scenario. Be aware that other foods toxic to pets—raisins, macadamia nuts, and coffee beans, for example—may have been ingested along with the chocolate. Even if you do not see any changes in your pet's behavior, you should contact your local veterinarian to determine whether any type of treatment is necessary.

For further information on chocolate toxicity, please contact your local veterinarian.

An archive of Pet Columns from the University of Illinois College of Veterinary Medicine is available online at Requests for reprints of this article may be directed to Chris Beuoy,

Veterinary Extension/Office of Public Engagement
University of Illinois College of Veterinary Medicine