In 2013, my life was changed by adopting a former lab dog, a floppy-eared beagle named Hammy, who spent his first several years in a research facility. When I first brought Hammy home, he was scared of sounds and sights in the real world, which made him shake with fear. Time and again, I crouched down to comfort him. 

I showed friends and strangers the ID tattooed inside Hammy’s velvety ear: CAICWZ. Most were shocked to learn we still experiment on dogs and asked questions I couldn’t answer. That led me on a journey with Hammy, a story I tell in my new book, "Lab Dog." 

In my reporting, I learned that dogs and humans share hundreds of diseases, and for centuries, we’ve used dogs and other animals to understand the workings of the human body. The first blood transfusion, in the 1600s, was between two dogs – a procedure that surely saved my life years ago when I needed pints of donor blood.

Dogs have helped us learn about anemia, diabetes, sleep apnea and a variety of cardiac, renal and age-related diseases. Today, dogs are

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