<P>Over the course of the twentieth century, the relationship between Americans and their domestic animals has changed dramatically. In the 1890s, pets were a luxury, horses were the primary mode of transport, and nearly half of all Americans lived or worked on farms. Today, the pet industry is a multibillion-dollar-a-year business, keeping horses has become an expensive hobby, and consumers buy milk and meat in pristine supermarkets. Veterinarians have been very much a part of these changes in human-animal relationships. Indeed, the development of their profession—from horse doctor to medical scientist—provides an important perspective on these significant transformations in America's social, cultural, and economic history.</P><P>In <I>Valuing Animals</I>, Susan D. Jones, trained as both veterinarian and historian, traces the rise of veterinary medicine and its impact on the often conflicting ways in which Americans have assessed the utility and worth of domesticated creatures. She first looks at how the eclipse of the horse by motorized vehicles in the early years of the century created a crisis for veterinary education, practice, and research. In response, veterinarians intensified their activities in making the livestock industry more sanitary and profitable. Beginning in the 1930s, veterinarians turned to the burgeoning number of house pets whose sentimental value to their owners translated into new market opportunities. Jones describes how vets overcame their initial doubts about the significance of this market and began devising new treatments and establishing appropriate standards of care, helping to create modern pet culture.</P><P>Americans today value domestic animals for reasons that typically combine exploitation and companionship. Both controversial and compelling, <I>Valuing Animals</I> uncovers the extent to which veterinary medicine has shaped—and been shaped by—this contradictory attitude.</P>