When people feel sick, doctors treat them. So, who treats animals? Veterinarians（兽医）are doctors for animals. But they also protect human health.

Veterinarians are the first line of defense against animal diseases that can spread quickly. Diseases, like some kinds of bird flu, can spread to humans. Others, like foot and mouth disease（口蹄疫）, cause economic damage.

Some veterinarians in the United States inspect animals raised for food. Some study diseases. Others work for drug companies and medical companies. And about half of all veterinarians care for more than one-hundred-million cats and dogs that Americans keep for pleasure.

Becoming a veterinarian is hard work. Students take two years of preparatory studies in college. They must learn in the classroom about animal biology, diseases, medicines and treatments.

Then, they attend four years in a college of veterinary medicine. There, students work in laboratories and treatment centers to gain real experience with animal health. They also learn to perform medical operations.

There are twenty-eight schools of veterinary medicine in the United States. More than eight-thousand-five-hundred students study the subject. Seventy-five percent of the students are women. About two-thousand new veterinarians enter the job market each year.

States give veterinarians official permission to treat animals. A veterinarian must take a test to receive a license from any state where he or she works.

A number of groups help veterinarians. The American Veterinary Medical Association is one of the oldest. It started in eighteen-eighty-nine. The organization officially approves schools that teach veterinary science.

The Department of Agriculture established the National Veterinary Accreditation Program in nineteen-twenty-one. The program was designed to teach veterinarians how to work with federal and state officials supervising animals raised for food. The program gives veterinarians extra training.

Veterinarians have always been important to agriculture and public health. They set broken bones, treat infectious diseases, perform operations and help animals give birth. Many also are involved in the study of diseases that spread among animals.

This VOA Special English Agriculture Report was written by Mario Ritter. This is Steve Ember.