You've all heard it before, "Don't give your dog chocolate it will kill him". You are probably wondering how true this statement really is. Do you have to rush your dog to an emergency vet if he ate one of your M&M's? How about if he ate an entire plate of brownies?
Chocolate is readily available, particularly at certain holiday times (like Valentine's Day and Halloween) and represents a potential lethal toxin for dogs. Many species are susceptible, including cats, but the dog is the most commonly affected. Excessive ingestion of chocolate was recently reported as one of the top 20 most common intoxicants in the dog. Cocoa bean hulls, cocoa mulch, or waste used for bedding for large animals, most commonly horses, have been a source of toxicosis as well.
The truth is, chocolate contains theobromine that is toxic to dogs in sufficient quantities. Theobromine is a xanthine compound in the same family of chemicals as caffeine, and the drug theophylline. The more chocolate liquor there is in a product, the more theobromine is present. This makes baking chocolate the worst for pets, followed by semisweet and dark chocolate, followed by milk chocolate, and finally chocolate flavored cakes or cookies.
The amount of chocolate that it takes to poison your pet depends on the type of chocolate he's eaten and his weight. White chocolate has the least amount of stimulants and baking chocolate or cocoa beans have the highest. Here is a list of the most common sources of chocolate and the amount that leads to toxicity:
Mild signs of toxicity can
occur when 45 ounces per pound of body weight is ingested. Severe
toxicity occurs when 90 ounces per pound of body weight in ingested. This means that a 20-pound dog would need to ingest at least 55 pounds of white chocolate to cause nervous system signs. A 10-pound cat would need to ingest 27 pounds. Yes, that is twenty seven pounds! White
chocolate has very little real chocolate in it. Therefore, the levels
of caffeine and theobromine are very low. Tremendous amounts of white
chocolate need to be ingested in order to cause toxic signs from
chocolate. It is highly unlikely that white chocolate ingestion will
result in the toxic neurologic signs but, the severe gastrointestinal
effects from a high fat food develop with much less white chocolate
Mild signs of toxicity can
occur when 3/4 ounce per pound of body weight is ingested. Severe signs
occur when 2 ounces per pound of body weight is ingested. This means
that a little less than one pound of milk chocolate can be toxic to the
nervous system of a 20-pound dog. A 10-pound cat would need to ingest
Mild signs of toxicity
can occur when 1/3 ounce per pound of body weight is ingested. Severe
signs occur when 1 ounce per pound of body weight is ingested. This
means that as little as 6 ounces of semi-sweet chocolate can be toxic
to the nervous system of a 20-pound dog. A 10-pound cat would need to
ingest 3 ounces.
Mild signs of toxicity
can occur when 1/10 ounce per pound of body weight is ingested. Severe
signs occur when 1/3 ounce per pound of body weight is ingested. Two
small one-ounce squares of baking chocolate can be toxic to a 20-pound
dog. A 10-pound cat would need to ingest 1 ounce of baking chocolate.
This type of chocolate has the highest concentration of caffeine and
theobromine and very little needs to be ingested before signs of
illness become apparent.
The good news is that it takes, on average, a fairly large amount of theobromine 100-150 mg/kg to cause a toxic reaction. Although there are variables to consider like the individual sensitivity, animal size and chocolate concentration.
On average, Milk chocolate contains 44 mg of theobromine per oz. Semisweet chocolate contains 150 mg per oz. Baker's chocolate 390 mg per oz.
Using a dose of 100 mg/kg as the toxic dose it comes out roughly as: 1 ounce per 1 pound of body weight for Milk chocolate 1 ounce per 3 pounds of body weight for Semisweet chocolate 1 ounce per 9 pounds of body weight for Baker's chocolate.
So, for example, 2 oz. of Baker's chocolate can cause great risk to an 15 lb. dog. Yet, 2 oz. of Milk chocolate usually will only cause digestive problems.
Therefore a dog sneaking a couple M&M's shouldn't have a problem, but it isn't a good habit to get into!
The following link will take you to an interactive chart to show you exactly how much and what type of chocolate your pet would have to ingest to reach a toxic level.
Theobromine is a Central Nervous System (CNS) and cardiovascular stimulant. It has a diuretic effect as well. Intoxication causes:
Tachycardia (racing heart rate)
Abnormal heart rhythm
Hypertension (increased blood pressure)
Polyuria (increased urination)
Death in severe cases
There is no specific antidote for theobromine, however a combination of detoxification, supportive and symptomatic treatment can be successful. Detoxification includes induction of vomiting within the first 1-2 hours of ingestion, gastric lavage, and activated charcoal administration. Administration of activated charcoal may inhibit the absorption of the toxin. The half life of the toxin is 17.5 hours in dogs, so detoxification may need to be continued for up to 72 hours.
Supportive therapy includes administration of muscle relaxants and control of seizure activity with anticonvulsant medications. Oxygen therapy, intravenous medications, and fluids might be needed to protect the heart.
Ultimately, the best solution is prevention. Information regarding the dangers of feeding chocolate and theobromine containing foods to pets is crucial to minimizing incidents of toxicosis. Limiting pet access to chocolate, particularly during holiday seasons, is one of the most important first steps toward prevention of chocolate intoxication.
If you suspect your pet has ingested chocolate contact the Merrick Veterinary Group at 516-379-6200 immediately! We can help you determine the the proper treatment for your pet.