Chocolate: Common Dog Toxin

Author: Jason Nicholas, BVetMed

Published: June 11, 2014

Updated: May 19, 2021

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chocolate is toxic to dogsMost dog 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.

What makes chocolate so bad for 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.

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.

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.

How do you know if your dog ate a toxic amount of chocolate?

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

To figure out if your dog has consumed a toxic amount of chocolate use this chocolate toxicity calculator.

NOTE: These are rough estimates and levels of toxicity based on the type of chocolate your dog has eaten, how much of it they've eaten, and your dog's weight. There are other factors involved in knowing if the chocolate your dog just ate will cause serious problems. If there is ever any doubt, the best thing you can do is call your veterinarian, your local Animal ER, or one of the dedicated animal-specific poison control hotlines.

What should I do if my pet eats chocolate?

In the event your pet gets into chocolate, you can use the chocolate toxicity calculator included above. Although the best thing you can do is contact your veterinarian or one of the animal-specific poison control centers for specific advice. Your pet's weight and the type and amount of chocolate they ate aren't the only factors that influence whether or not their "chocolate snack" is likely to cause a problem.

If your dog is already showing signs of toxicity – such as anxiousness, restlessness, seizures, panting, vomiting, or diarrhea – they need to be seen by a veterinarian immediately.

Chocolate toxicity can be 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) 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.

Special circumstances: Other things that might be in chocolate and cause problems for pets

In some cases, it's not just chocolate in the candies, cookies, brownies, and other chocolate-containing things your dog might eat. Here are a few common "additional goodies" that might be in chocolate-containing products that your dog might get into which could cause their own set of problems:

  • Xylitol: Xylitol is an increasingly common sugar substitute that is especially popular with people who are diabetic, eating a keto-diet, or otherwise watching their caloric and carb intake. Xylitol is HIGHLY toxic to dogs ... even in very small amounts.
  • Raisins: Raisins (along with grapes and currants) can cause severe kidney damage in some dogs.
  • Macadamia nuts: These nuts can cause a sudden inability for a dog to use their back legs, tremors, and also a high fever. Fortunately this toxicity tends to be self-limiting, but it's still quite disconcerting and can be dangerous.
  • Marijuana (THC): Marijuana can cause both nervous system and heart/circulatory problems in dogs.
  • Liquor: If you're a fan of chocolate cordials, be aware that the liquor in these chocolate treats can cause an array of additional problems for your dogs should they gobble them up.

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. So this one tip can also help protect your pets from medication toxicities and a host of other potential problems, too!

  • 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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