How toxic is chocolate for your pets?

By Charlie Powell, Tooth & Nail

The call came from a friend Saturday night, even though he knows I am not a veterinarian.

“My dog ate my brownies, will he be OK?”

While he and his significant other were concerned, they also did not want to begin spending money for a perhaps unnecessary emergency veterinary call either. So, they called a friend who might know.

“So tell me what happened,” I asked.

The caller told me earlier in the evening his dog ate a whole plate of about a dozen brownies baked in the shape of cookies. He also said he’d given the dog hydrogen peroxide to drink and he’d seemingly thrown up all of the cookies.

Hydrogen peroxide can be used to induce vomiting in dogs, pigs, ferrets and cats according to the ASPCA’s Animal Poison Control Center.

“The dosage (of 3-percent hydrogen peroxide) is 1 teaspoon per 5 lbs., not to exceed 3 tablespoons,” writes veterinarian Jill A. Richardson. “It should be administered undiluted — not mixed into water or food. However it is helpful to feed a small, moist meal of either canned food or a slice of bread before inducing vomiting, as it makes emesis more productive by giving the toxicant something to adhere to.

“Bulb syringes, feeding syringes, or turkey basters aid in administration. Hydrogen peroxide causes vomiting through mild gastric irritation. Vomiting usually occurs within minutes and can be repeated once if not initially successful at causing emesis.”

At the time of the call, the dog was resting comfortably and seemed fine. But I had to ask another question.

“Were the brownies ‘magic’ brownies by chance?” Meaning, had the well-meaning baker maybe mixed some cannabis in for a better Saturday night?

There was a long pause. As I listened, I thought that either means they were magic brownies and he was a little embarrassed or he was trying to process old English from the 1960s and ’70s. Fortunately, it was the latter.

“Oh no, nothing like that, just a regular batch of brownies,” he said.

“Well to be safest, you should call a veterinarian and likely there will be little or no charge,” I said. “Alternatively, you can call the ASPCA’s Animal Poison Control Center for a telephone consultation and there is a small charge for that.”

Given the size of the dog, the forced vomiting of what appeared to be most of the brownies, and the fact the dog was not showing signs of intoxication, I also said, “As a layperson ... if the dog were mine, I’d wait and watch. If he gets sicker, take him in.”

Most people know that “chocolate is toxic,” but like most things in the biologic and sociologic worlds, it’s not that simple. It is a component in chocolate, theobromine, that is the toxic agent. Yes, the caffeine, excess fats and sugars don’t help either.

Chocolate is rarely fatal but can make dogs and cats quite ill. Every veterinarian can tell you stories about the elderly couple with the small dog that eats chocolate every day because its owners eat chocolate every day. The dog has become adept at begging, eye contact and inducing guilt in the primates, thus forcing them to feed it. Who’s trained who?

Medicinally, theobromine and caffeine are both used on occasion to stimulate the heart, make animals urinate, dilate blood vessels and relax smooth muscles.

Both chemicals are not metabolized well by dogs and so they tend to hang around in the system, making the animals relatively more sensitive. How much is too much?

We’ll track that next week as we get closer to Halloween.

Charlie Powell is the public information officer for the Washington State University College of Veterinary Medicine, which provides this column as a community service. For questions or concerns about animals you’d like to read about, email

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