Published: Feb. 17, 2003

Chickens, dogs, cows and cats are all domesticated animals found in America today. While some sleep on personalized beds in our homes, others are packed by the hundreds under one roof awaiting a date with the dinner table.

So why do we eat some and treat others as members of our families?

Susan D. Jones, a practicing veterinarian and history professor at the University of Colorado at Boulder recently published a book that answers this question, and delves into the issue of how Americans have reconciled animal welfare concerns with our reliance on animals for food and other products.

In her book "Valuing Animals: Veterinarians and Their Patients in Modern America," Jones shows that over the past century veterinarians have heavily influenced the way Americans value and interact with pets, livestock and other domesticated animals today.

"For example, although animals are usually considered to be property and sources of profit, Americans' interest in animal companions has transformed the status of pets during the past century," Jones said. At the same time, the animals that are used for food have become nearly invisible to most Americans.

And veterinarians helped shape this transformation, according to Jones, one of only two practicing veterinarians in the nation with a doctoral degree in history.

At the beginning of the 20th century, most veterinarians focused on treating animals that provided transportation, food or other material resources. They were essentially horse doctors, according to Jones. As horses' significance in society was eclipsed by motorized vehicles, veterinarians turned their attention to the livestock industry, hoping to make it more sanitary and profitable. All the while, the public still perceived animals as mostly economic assets.

With the spread of factory farming, the number of animal producers declined, cutting into the customer base of many rural veterinarians, forcing yet another job description change for the field.

In the 1930s many veterinarians began focusing their expertise on pets, Jones said. Pets, particularly dogs, became increasingly popular, especially with war stories promoting animal heroism. Rin-Tin-Tin became a cultural icon, and Lassie a movie star. By the end of the century, veterinary medicine in America concentrated largely on the health of pets, allowing pet care to become integrated into our mass consumer culture.Ìý

"Veterinarians recognized and took advantage of the sentimental value of pets, which they transferred into a mandate for pet medical care and thus an animal care industry," Jones said. "People in America now have the money to care for their pets more extensively. But more importantly we are willing to spend the money because these animals are valuable to us as companions."

At the same time, other animal industries such as meat and egg production have been removed from the public eye. "We interact daily with our pets, but purchase our meat shrink-wrapped in the grocery store," she said. "This has helped Americans to view our relationships with domesticated animals as more humane than ever before in our history."

The book also highlights the important roles that animals have played in American history.

Jones joined the CU-Boulder history department in fall 1998 and has since introduced four new courses, including "Gender and the History of Science" and "Health and Disease in the United States."

She completed veterinary school at the University of Illinois at Champaign-Urbana and worked as a veterinarian for three years. While working in the field, she decided to become a teacher, and went back to school to earn her doctorate in the history and sociology of science.