Who can resist chocolates — the aroma, the taste, the texture? Not me, and not my dogs. For people, a little extra chocolate may mean a restless night and a few inches added to the waistline. For dogs, chocolate can mean death.
Chocolate comes from the roasted seeds of the cocoa plant. Within these seeds are alkaloid compounds called methylxanthines, specifically theobromine and caffeine. These compounds compete with normal body chemicals for receptor sites in the brain and muscles. By blocking the body's normal chemicals from reaching these receptors, they raise havoc with the heart and nervous system.
Initially, dogs that eat a toxic amount of chocolate may drink a lot of water, vomit, or have diarrhea. Their abdomens may appear enlarged, and they may become restless.
Signs then progress to include hyperactivity (think of yourself after 4-6 cups of coffee), wobbliness, tremors, stiff muscles, and seizures. Their heart rates increase dramatically, and heartbeats may become irregular. They begin to breath fast, overheat, and may turn blue.
Eventually they may enter a coma and die, usually because of the irregular heartbeats or breathing difficulty. Dogs that survive may get inflammation of their pancreas, the organ that produces digestive enzymes, resulting in severe abdominal pain, vomiting, and even organ failure. Hard to believe that a much loved treat can have such fatal effects in our canine companions!
How much is too much?
Fatalities usually occur from ingestion of cocoa shell mulches or concentrated baking ingredients such as baking chocolate or cocoa powder.
Theobromine contents for some common forms of chocolate are listed below. Mild signs of illness occur with ingestion of 20 mg/kg, severe signs with 40-50 mg/kg, and seizures with 60 mg/kg. A 70-pound retriever might have to eat 10 to 15 ounces of milk chocolate — the whole box of chocolate valentine truffles — to get sick, but 4 ounces of baking chocolate could be the death of him.
If your dog eats too much chocolate, his stomach will need to be emptied, either by induced vomiting or, if he is unstable or unconscious, by a "gastric lavage".
Basically, your veterinarian will need to hose out his stomach, and then fill it with a charcoal compound to absorb the remaining contents. The charcoal administration may need to be repeated for several days because chocolate can form a mass in the stomach that is not easily removed or dissolved. Intravenous fluids are usually given to help flush the toxins from the blood stream and out the kidneys. Other drugs may be required if your dog has any heartbeat irregularities or seizures.
Most dogs make a full recovery after a bout of chocolate overindulgence but, of course, the best treatment is always prevention. So, keep the chocolates out of reach of your canine companion, or consider gift certificates or flowers next year.
Type of chocolate Theobromine content
Milk chocolate 58 mg/oz.
Semi-sweet chocolate chips 138 mg/oz.
Cocoa bean hulls 255 mg/oz.
Unsweetened baking chocolate 393 mg/oz.
Cocoa powder 737 mg/oz.