The potential for a disease to pass from animals to people had been understood for millenniums, but it was not until the late 18th century, when Edward Jenner developed a vaccine for smallpox, that someone found a way to prevent it. The idea that government could take a systematic approach to fighting disease in animals to protect people did not take hold until the middle of the 20th century, when, according to a N.Y. Times obituary, Dr. James Steele led the way.

He helped establish mass vaccination and prevention programs in the United States for diseases like rabies and bovine brucellosis. After setting up federal programs, he helped start them at the state level. He visited dozens of countries to start veterinary public health programs and to help trace specific diseases, like Rift Valley fever in Nigeria, where he traveled in the 1970s. He constantly looked beyond his immediate field: in 1964, he published a paper titled “The Socioeconomic Responsibilities of Veterinary Medicine.”

He participated via Skype this summer at the annual conference of the American Veterinary Medical Association in Chicago during a lecture series, “The James Steele Challenge: A Better World Through One Health.” It focused on his lifelong passion: convincing people that economic prosperity was rooted in animal, human and environmental health. Scores of students cite him as their mentor.

In 1942, a year after Dr. Steele received his doctor of veterinary medicine degree from Michigan State University, he became one of the first veterinarians to receive a master’s degree in public health from Harvard. In 1945 he started the veterinary public health program at the United States Public Health Service in Washington. In 1947, he and the unit moved to Atlanta, to what is now called the Centers for Disease Control and Prevention.

Two years after that he went to work for the office of the surgeon general as chief veterinary officer. He became the nation’s first assistant surgeon general for veterinary affairs in 1968 and deputy assistant secretary for health and human services in 1970. The formal name for the types of diseases Dr. Steele dealt in, which pass from animals to humans, is zoonoses. While he had strong science and field experience — his interest in pursuing a veterinary degree increased after he helped investigate a brucellosis outbreak in a lab at Michigan State in the 1930s — his special talent was in finding practical ways to address disease on a large scale.

“He had to take all that science and translate it into a disease control program,” said Dr. Peter Cowen, who teaches epidemiology and public health in the college of veterinary medicine at North Carolina State University. “Jim took the science and protected public health.”

James Harlan Steele was born on April 3, 1913, in Chicago to James Hahn Steele and the former Lydia Norquist. He grew up, all the way to 6-foot-7, in Chicago, and stayed there into his 20s, selling insurance to help his family before he entered Michigan State.

In 1971, he became a professor at the University of Texas School of Public Health in Houston.

“The impact of veterinary research through the years has been startling,” he wrote in the 1960s. “It has opened vast areas of continents to animal husbandry, given a base to many industries and improved human nutrition beyond expectation. Probably in no other creative area has an investment returned so great a dividend for mankind.”

He retired in 1983. His survivors include his wife, Brigitte; his sons, Michael, James and David; and four grandchildren. His first wife, the former Aina Oberg, died in 1969.