Q: Our dog Riley ate a lot of semisweet chocolate bits. His veterinarian advised us to use hydrogen peroxide to make him throw up. After Riley vomited all the chocolate, he was fine. What are the toxic effects of chocolate? How much does it take to make a dog sick? A: Before I became a veterinarian, one of my golden retrievers ate a big bag of Hershey’s Kisses. His vet gave me the same advice—and up came all the Kisses, most still in their foil wrappers with the little paper plumes standing in salute. Once I entered the veterinary field, I learned how dangerous chocolate can be for dogs. Part of the problem is that dogs devour chocolate until it’s gone, ingesting more than even I, who love the sweet, can eat at one sitting. Fortunately, you witnessed Riley’s indiscretion and acted quickly. If you hadn’t, he might have experienced …