As science journalist Melanie D.G. Kaplan describes in her new book, “Lab Dog,” tens of thousands of beagles are used in the U.S. for medical research, testing chemical safety, and more. In “Lab Dog,” Melanie goes on a journey with her beloved adopted beagles, Hammy, a retired research dog, to find out where he came from. Along the way, she explores the ways that dogs contribute to medical research, the potential and limitations of substitutes for animals in the lab. In this episode, we discuss the ethics of animal research, Hammy’s story, the U.S. government’s attempt to move away from animal research, and why the number of beagles used in lab research has dropped from 70,000 when she adopted Hammy to 40,000 today.