“My dog ate chocolate, is he going to die?”

by Sgt. Dale Kelly

Veterinary Clinic

You wake up on Easter morning and you head downstairs to watch the children open their Easter baskets. You stop in utter disbelief when you see that your mischievous puppy Spot has beaten everyone to the baskets and has eaten the first 16 ounce chocolate rabbit and has just started on the second one. You have heard that chocolate is poisonous to dogs, but is it true? What should you do next?

The truth is chocolate contains theobromine that is toxic to dogs in sufficient quantities. It is a xanthine compound in the same family of caffeine.

Toxic levels

The good news is that it takes, on average, a fairly large amount of theobromine, 100-150 mg per pound of your animal, to cause a toxic reaction. Although there are variables to consider like the individual sensitivity, animal size and chocolate concentration.

White chocolate contains 1 mg per ounce of theobromine. The toxic dose is 200 ounces of white chocolate per pound of body weight. For example 250 pounds of white chocolate will cause signs of nervous system poisoning in a 20-pound dog, 125 pounds in a 10-pound dog.

Milk chocolate contains 60 mg per ounce of theobromine. The toxic dose is one ounce of milk chocolate per pound of body weight. For example one pound of milk chocolate is poisonous to the nervous system of a 20-pound dog; one-half pound in a 10-pound dog. Keep in mind that the average chocolate bar contains two to three ounces of milk chocolate. It would take two to three candy bars to produce toxicity in a 10-pound dog.

Semisweet chocolate contains 150mg per ounce of chocolate. The toxic dose is 0.3 ounces of semisweet chocolate per pound of body weight. One-third of a pound of sweet chocolate is toxic to a 20-pound dog; 1/6 of pound for a 10-pound dog.

Baking chocolate contains 450 mg per ounce of theobromine. The toxic dose is 0.1 ounces of baking chocolate per pound of body weight. Two one-ounce squares of bakers chocolate is toxic to a 20-pound dog; one ounce for a 10-pound dog.

It would seem that it is all right to let your dog have a chocolate treat every now and then if it is the right kind and it is not very often.

The problem with feeding a dog chocolate as a treat is that it develops a liking for chocolate. Since dogs do not seem to be as sensitive to bitter tastes as humans, they may then eat the more toxic baker's chocolate or they may consume a toxic amount of milk or semi-sweet chocolate if it can get into an improperly stored supply.

What are the signs of toxicity?

Signs are most commonly seen within 12 hours (or less) of chocolate ingestion.

* Excitement / nervousness / trembling

* Vomiting / diarrhea

* Excessive thirst / sometimes excessive urination.

* Muscle spasms

* Seizures

* Coma (rare)

* Death (rare) -- likely due to heart rhythm abnormalities.

How is chocolate toxicity treated?

If you suspect that your pet has eaten chocolate (more than the stray chocolate chip that fell on the floor), call your veterinarian for advice.

The toxicity of theobromine is dose dependent. This means that the size of your pet, the type of chocolate, and quantity of chocolate determine if or how toxic it is for your pet.

There is no specific antidote for theobromine toxicity. Medical treatments are supportive, and may include all or some of the following:

* IV fluids - to prevent dehydration from vomiting, diarrhea, and /or increased urination, and to "flush" the theobromine out of the system.

* Emetics - medications that induce vomiting. Used when the ingestion of chocolate is within four hours. Up to eight hours post chocolate ingestion may be effective.

* Activated charcoal - for ingestion greater than four hours prior to treatment, or for patients that show continued signs of toxicity.

* Anti-seizure medications - for patients having seizures and/or muscle tremors.

* Cardiac medications - for patients exhibiting irregular heart rates or rhythms.

What is the prognosis for chocolate toxicosis?

The expected course of chocolate toxicosis is 12 to 36 hours depending on the dosage and effectiveness of treatment. Prognosis is good if the chocolate is removed within two to four hours of ingestion. Prognosis is guarded in animals with advanced signs such as seizures and serious heart dysfunction.

A National Animal Poison Control Center Hotline is available at 1-800-548-2423.

There is a modest fee for the service to support the Animal Poison Control Center.