Most of us enjoy a little chocolate now and again. Some of us enjoy a lot! But this sweet treat can turn deadly fast if our canine pals get a hold of it. Most dog owners are aware that chocolate isn’t good for dogs. But the amount of chocolate and the mechanisms by which it can make our dogs very sick, or even kill them, remain a mystery to most. Unfortunately ignorance can lead to death if the ingestion of this dangerous toxin is not taken seriously.
Chocolate is one of the most common causes of poisoning in dogs. Some dog parents unknowingly poison their dogs by giving them chocolate as a treat. It is also incredibly common for dogs to gain access by foraging in the house for food. My own dogs opened heavy cabinet doors and tore through two boxes to access chocolate in my home.
Chocolate is a common gift at the holidays. Valentine’s Day, Easter, and Christmas are all times when your dog may be more at risk to gain access to chocolate. A well-intentioned gift under the Christmas tree can turn deadly if you have a curious hound in your home.
So why is chocolate toxic to dogs and not to humans?
The simple answer is quantity. The scientific name of cocoa is Theobroma Cacao and it contains a substance called theobromine. It also contains caffeine. These substances are methylxanthines, and can have a negative effect on many animals, including humans. Methylxanthines are stimulants, and are capable of causing problems with the cardio vascular system if taken in extreme quantities. Fortunately for us, those quantities in humans are fairly high.
We also have the added advantage of having the correct enzymes to process methylxanthines and remove them from our bodies quickly. The main purpose of the liver is to clean the blood. Toxins in the blood are removed and, hopefully, passed out of the body through the kidneys. Humans have the enzymes necessary to process methylxanthines present in the blood, and break it down in the urine. But while protein enzymes make up a great deal of an animal’s tissue, we do not always share the same kind of enzymes as the rest of the animal kingdom.
Dogs do not have the enzymes necessary to process methylxanthines like caffeine and theobromine. A dog’s liver does not have the enzymes necessary for the liver to break these substances down, and therefore they are not effectively removed from the blood stream. The half-life (amount of time to reduce the concentration by half) of theobromine in dogs is 17 hours, and caffeine is 4.5 hours. This means that these can stay in your dog’s system for a long time.
In large enough doses, stimulants can be harmful to any animal. But because these substances stay in your dog’s system longer than they do in ours, they are especially harmful to your dog.
We tend to think of theobromine as a relatively harmless substance. The level required to reach toxicity in humans is more than three times of that required for dogs. This amounts to a quantity of chocolate that most people could not even consider ingesting. But chemically, theobromine is in a class of compounds called alkaloids, which are derived from plants. Some other alkaloids are morphine, cocaine, nicotine, caffeine, strychnine.
Theobromine causes the release of norepinephrine and epinephrine, hormones released by the adrenal gland. These cause constriction in most blood vessels, but epinephrine causes dilation in the blood vessels of the liver and skeletal muscles. They increase the contraction strength and volume of blood pumped by the heart, raising the blood pressure.
Epinephrine is the hormone that prepares the body for an emergency, and is released during stress. Because dogs cannot regulate theobromine and caffeine, these hormonal reactions can cause cardiac episodes in dogs. Epinephrine also acts on the liver to secrete liquids and process sugars. The impact of theobromine on the liver can lead to long term problems with the liver.
The other danger chocolate may pose to your dog is the fat content that may be present. Dogs who are exposed to high amounts of fat all at once commonly develop pancreatitis. Pancreatitis is potentially life threatening. In combination with the damage done to the heart and liver by theobromine, chocolate can also damage your dog’s pancreas. It is simply not worth the risk to allow your dog access to any amount of chocolate.
What do I do if my dog eats chocolate?
If you catch your dog eating chocolate, don’t panic, but do act immediately. This article is no substitute for veterinary care. According to the Merck Veterinary Manual, toxic signs may show up in dogs that ingest 20 mg per kg of body weight (or 0.006 oz. theobromine for a 20 lb. dog). Cardiovascular problems may show up at twice that, and seizures may begin at three times that dose.
Cocoa powder has the highest concentration of theobromine, followed by bittersweet and dark chocolate. Milk chocolate has less, and white chocolate has very little. A twenty pound dog can die by eating about 20 oz. (or 1.25 lbs.) of milk chocolate. Less than that will still make them very sick and cost you hundreds of dollars in vet bills.
A single Hershey bar is unlikely to cause death in all but the smallest dogs, but should still be treated as an emergency. Baked goods that are chocolate flavored typically have less cocoa in them, but they are still not a good treat for your dog. Just because your dog has ingested less than this does not mean that your dog cannot become very sick. Seek veterinary care immediately!
If you know your dog has just ingested chocolate, the best thing to do is call your vet or the local emergency veterinary clinic. If the exposure is recent (less than two hours), your vet will most likely urge you to induce vomiting. If you are unable to reach anyone, you may be able to induce vomiting on your own. You want to get as much of the chocolate out of the stomach before toxicity sets in. To avoid serious medical complications it is critical to get the chocolate out as soon as possible.
The following chart contains dosages of 3% hydrogen peroxide that can be used to induce vomiting from Bruce Fogle, DVM’s book Caring For Your Dog. Hydrogen peroxide can be found at any pharmacy or big box store, and is relatively inexpensive. You may want to consider keeping some on hand for an emergency, but it should be replaced periodically in order to insure its effectiveness. If the solution is more than 3% you must dilute it.
Unfortunately, chocolate can ball up in your dog’s stomach and be difficult to remove. But you should get out as much as you can if your dog is going to survive.
|Dosage||Weight of dog|
|½ Teaspoon||Under 5 lbs|
|1 Teaspoon||5-10 lbs|
|2 Teaspoons||10-15 lbs|
|3 Teaspoons||15-25 lbs|
|4 Teaspoons||25-35 lbs|
|5 Teaspoons||35-45 lbs|
|6 Teaspoons||45-55 lbs|
|7 Teaspoons||55-65 lbs|
|8 Teaspoons||65-75 lbs|
|9 Teaspoons||Over 75 lbs|
Once toxicity has set in, you will need to go straight to your vet or the nearest veterinary emergency room. This should be treated as an emergency. Even if you are able to get your dog to vomit, the best course of action is to seek veterinary care as soon as possible. Any of the theobromine that has made it into the dog’s system can cause dangerous long term medical problems.
Not only is it bad for your dog, if your dog has long term damage it will impact your wallet through specialized care and potentially expensive medication.
It is always better to be safe than sorry.
Symptoms of chocolate poisoning in dogs
|(From “Dog Chocolate Toxicity Meter.” Chocolate Toxicity Meter. Pet MD, n.d. Web. 06 July 2015).|
Because most people have been enjoying chocolate from the time they were children, it would be easy to underestimate the damage it can do to your dog. The risks to your dog are very real. Depending on the amount and type of chocolate your dog has eaten the prognosis will vary from good to very poor.
It is critical to act quickly. The sooner your dog gets treatment, the better the prognosis. Even if you are successful at inducing vomiting, you should still see your veterinarian in case your dog still has chocolate in his system, or he digested enough of it to hurt him.