Friday, November 4, 2011

The skinny on chocolate (toxicity)

This is my favorite time of year, hands down. I love the holidays - especially Thanksgiving and Christmas. For the first time in more than 5 years, I have both major holidays off of work and will be spending them with my family! I am very excited about this. It will be unlikely to occur again for many years. Well, unless I get pregnant again soon and go on maternity leave that happens to correspond with the holidays.

One of the small things I love about the holidays is the abundance of candy. Starting at Halloween and continuing through the end of the year, chocolate treats abound. I'm trying to be **more** careful about these sweet treats due to my gestational diabetes and predisposition for Type 2 diabetes, but it's hard. Imagine then how hard it must be for a dog! They have no sense of "good idea or bad idea" - they only know that chocolate smells (and tastes) delicious.

Chocolate ingestion is something I see all the time in the ER. The numbers certainly go up around the major fall holidays. Thus, I thought we could talk frankly about chocolate toxicity here.

My take on it? Chocolate toxicity does not exist.

I say that slightly tongue in cheek. But not really. Let's first talk about why chocolate causes problems for dogs (and people who eat too much of it). Chocolate contains 2 important substances : theobromine and caffeine.

Theobromine is an alkaloid found in chocolate. It is a fascinating compound that has medicinal effects. One of these is the treatment of asthma, as it relaxes the smooth muscles in the bronchi, allowing bronchodilation. Caffeine is actually metabolized into theobromide within the human body. Theobromide leads to increased heart rate and vasodilation leading to decreased blood pressure. It can also lead to tremors, nervousness/excitability, and seizures at higher amounts.

In small quantities, theobromide is not toxic. This is why we can all enjoy chocolate deliciousness. However, in large quantities in people and in dogs (who metabolize chocolate more slowly), toxicity CAN occur.

The early signs of chocolate OD in dogs are vomiting, diarrhea, and increased urination (diuresis). As the amount of exposure increases, the clinical signs worsen leading to tremoring and possibly seizures. Death can occur.

Still, I have only seen a couple of severe cases - dogs with heart rates of 190-250. They responded well to fluid diuresis, mild sedation, and beta blockers to slow the heart rate. And I have seen one dog that presented for chocolate intoxication die. His death was sudden and inexplicable. It was a small chihuahua. His heart rate was very high, but he was alert and active. He had no other health problems. He was in his kennel, receiving fluids, barking his head off, and about to be sedated, when he suddenly and unexpectedly dropped dead. Resuscitation was not successful. I still have no idea to this day if this was really a chocolate related death or some other problem (underlying heart disease).

The vast majority of the dogs that eat chocolate do just fine with no treatment. It is massive ingestion that is worrisome. Also, the darker the chocolate, the more concerning. Pure cocoa is bad! Milk and white chocolates are barely worth concerning oneself over.

Rule of thumb? Apply common sense. If your 70 pound Labrador ate 1 snack size KitKat, he is not going to die. If your 70 pound Lab ate an entire bag of dark baking chocolate, a trip to the ER is warranted. The reason I say that chocolate toxicity "does not exist" is because it is very, very, very rare to see serious consequences as a result of chocolate ingestion. Most dogs just don't eat enough or the right kind (dark) of chocolate to have any problems other than mild hyperexcitability.

When in doubt, call your local veterinary ER - we are happy to talk to owners about quantity and toxicity. We do it ALL the time.

1 comment:

Nicki said...

There is no end to the calls about 3 m&ms, 2 chocolate chip cookies, one brownie, 4 small hershey bars...

At least we get to make people happy and tell them their dog will be ok.