Why is Chocolate Toxic for Pets?

Author: Jason Nicholas, BVetMed

Published: October 19, 2016

Updated: June 15, 2021

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chocolate is toxic to cats and dogsMost pet owners already know that chocolate is bad for dogs. In fact, so many people are aware of this common toxicity that veterinary hospitals across the country regularly receive phone calls from pet owners concerned because they realized their pet just ate some chocolate – even if that pet is a 65-pound Labrador Retriever that just ate a few M&Ms.

So in this article, we won’t focus on the fact that chocolate is bad for pets – you (hopefully) already know that. We’re going to focus on why chocolate is toxic, which types of chocolates are the worst, and what signs you should look for in the event you suspect chocolate toxicity.

Problems with Chocolate:

  1. The biggest concern of chocolate toxicity is hyper-stimulation, which can lead to significant and potentially fatal problems in pets.
  2. If your pet gets into chocolate, the best thing you can do is contact your veterinarian or animal poison control immediately.
  3. Don’t forget, chocolate toxicity can prove fatal, so don't delay or take a "wait and see" approach.

What makes chocolate so bad for cats and dogs?

The primary concern with chocolate is due to a chemical compound called methylxanthines. If you've ever pulled an 'all-nighter' in college or if you require a cup of coffee in the morning to ‘wake up,’ you're likely already well-acquainted with one type of methylxanthine – caffeine. The methylxanthine that we primarily worry about with chocolate toxicity is called theobromine.

Theobromine can have a wide range of effects in your pet's body. In the case of chocolate toxicity, the biggest concern is hyper-stimulation of both the central nervous system (including the brain) and the heart. This excessive stimulation can lead to significant and potentially fatal problems in pets, including:

  • General hyper-excitability and anxiousness
  • Seizures
  • Rapid heart rate (tachycardia)
  • Abnormal heart rhythms
  • Cardiac arrest

The amount of theobromine in chocolate varies significantly with the cocoa content of the chocolate. The darker the chocolate, the higher the cocoa content, and the greater the theobromine concentration. In other words, the darker the chocolate, the greater the risk to your pets.

The amount of chocolate your pet eats, and their size and weight, are also factors in their risk of toxicity.

Check out this veterinary chocolate calculator

NOTE: that these are estimates and many factors play a role in toxicities, please don’t test these or ever intentionally feed your pet any quantity of chocolate.

What should I do if my pet eats chocolate?

chocolate, the best thing you can do is contact your veterinarian or one of the animal-specific poison control centers for specific advice.

If your pet is already showing signs of toxicity – such as anxiousness, restlessness, seizures, panting, vomiting, or diarrhea – he or she needs to be seen immediately by a veterinarian.

Don’t forget, chocolate toxicity can prove fatal, so don't delay or take a 'wait and see' approach.

In cases where heart or brain issues are present or expected to develop, these pets will need to be hospitalized for treatment and monitoring. Their treatment is likely to include induction of vomiting, administration of activated charcoal (multiple doses at periodic intervals, due to the enterohepatic recirculation of the toxin), intravenous fluids, and continuous monitoring of their heart rate and rhythm (ECG). Additional specific treatments will be necessary if seizures or heart issues are present or develop.
A secondary problem that often develops in cases of chocolate ingestion is pancreatic inflammation (pancreatitis in dogs and cats) caused by the high-fat content of chocolate. The signs of pancreatitis can take a few days to develop, but typically include ongoing diarrhea and vomiting, as well as significant pain for the affected pet.

How can I prevent my pets from eating chocolate?

There are several easy and effective ways to prevent chocolate toxicity. Following these tips can save you the heartbreak and expense caused by your beloved pet becoming sick.

  • Be careful when baking. Chocolate chips, chocolate bars, cocoa powder, and blocks of baking chocolate are often used in quantities that can easily land your pet in the emergency room.
  • Don't leave baked goods or other desserts out on tables or near the edge of countertops.
  • Teach your children the dangers of chocolate to pets so they are not inclined to ‘share’ with pets and will be careful to pick up any chocolate they may drop.
  • If you host overnight houseguests, keep their suitcases and other bags off the floor and insist they keep the door to their room (and bathroom) securely closed.
  • After all, you never really know what overnight guests bring in their suitcases.
  • Pay special attention during the holidays. Chocolate is often a main component of several holiday celebrations, including Christmas, Easter, Valentine’s Day, and Halloween. If you wrap chocolates or food containing chocolate as gifts, don't leave them in reach of your pets. Wrapped or not, your pets are sure to sniff them out and help themselves.
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