Atlanta ? When medical detectives track the source of a new outbreak, increasingly they look no farther than the animal world.

That’s because about 75 percent of all new infectious diseases — including high-profile ones like SARS, bird flu, monkeypox and West Nile virus — originate from animals.

As a result, veterinarians and other animal disease researchers are often needed to help combat these emerging germs among humans.

“Many of the world’s major diseases are either diagnosed or the initial control is done by veterinarians,” said Dr. Keith Prasse, dean of the college of veterinary medicine at the University of Georgia. “They are on the front lines of public health itself.”

Vets have helped investigate outbreaks on cruise ships and led field teams during the 2001 attacks of anthrax, traditionally a disease seen in cattle.

“You’re just as likely to find a bioterrorist agent in an animal health diagnostic lab or vet office as a physician’s office or hospital,” said Dr. Lonnie King, dean of the Michigan State University college of veterinary medicine.

Animal researchers have been instrumental in working to understand the avian flu outbreak in Asia and the West Nile virus at home. Both originated in birds.

“We have a new world in terms of the epidemiological convergence of animal health” and human health, King said. “It’s an epidemiologic collision.”

The collision comes from an ever-shrinking planet that increasingly allows humans and animals to trade maladies. Humans have given tuberculosis to wildlife. Last year’s monkeypox cases in the Midwest were spread by prairie dogs bought as pets that were infected by imported African rodents carrying the disease.

While vets are important to disease control, it’s difficult to attract them to public health, Prasse said.

That’s because private practice for vets, just as for medical doctors, can be more lucrative than a career in public service. Another problem is that many vet students aren’t familiar with public health careers.

“I discovered public health by accident,” said Dr. Jennifer McQuiston, a veterinary epidemiologist with the Centers for Disease Control and Prevention.

The importance of vets is highlighted at the CDC, which has 80 vets on its staff as epidemiologists. The agency recently created a new office to coordinate its vets, who work in different disease branches, and to recruit new ones as future disease detectives.