TO GUARD THE HEALTH OF MAN AND ANIMALS--Our Goal

ANIMAL DISEASES

THE UNITED STATES DEPARTMENT

OF AGRICULTURE - WASHINGTON, D.C.

the yearbook of agriculture 1956

Our Battle Against Animal Diseases

D. VAN HOUWELING

A NEW YORK milkman named Peter Dunn bought a milk cow in 1843 from the captain of the Washington, a British ship. It seemed to Peter Dunn that he was getting the cow at a big bargain, but she turned out to be just as expensive as Mrs. O'Leary's cow, which supposedly caused the big fire that destroyed one-third of Chicago in 1871. Peter Dunn's cow introduced contagious pleuropneumonia into these United States and cost our livestock Owners untold dollars.

Before Peter Dunn's time, animal diseases were a minor problem in the United States. Until the colonization of America, native livestock were free Of many of the diseases that trouble us today. Stock later imported from Europe brought diseases with them, but lack of transportation limited the spread of the diseases. As the country and the livestock population grew, however, our livestock disease problems grew in proportion.

Enterprising stockmen were continually improving our breeds through importations of the choicest animals from the best herds and flocks of the Old World. The glowing prospects of an extensive export trade in animals and their products gave an impetus to the livestock industry and brought our people to realize more fully the importance of this phase of agriculture.

On the farms of this country in 1883, the year before the establishment of an organized animal-disease-eradication program, there were an estimated 10,838,111 horses, and 1,871,079 mules, 41,171,762 cattle, 49,237,291 sheep, and 43,270,086 hogs a total of 146,388,329 animals valued at 2,338,241,519 dollars.

But up to 1883 livestock diseases had received little attention from State or National Governments. Contagious pleuropneumonia had existed along the Atlantic coast since Peter Dunn's fateful purchase 40 years before. From 25 million to 30 million dollars' worth of hogs were dying each year from hog cholera. Sheep raising had become precarious in many sections because of scab and other parasitic diseases. Tuberculosis and brucellosis were spreading. Anthrax and blackleg were on the increase in most of the States.

Cattle raisers lived in fear of Texas fever. The causes of the most destructive animal diseases were unknown or in dispute, and livestock owners to a large extent were defenseless, as veterinary science had not been able to provide effectual prophylactic or medical treatment.

Vexatious and expensive quarantines were increasing--some were for protection, but some were only for retaliation. Our system of interstate and export animal transportation was denounced as a disgrace and an outrage on the first principles of humanity. There was a growing demand for protection of the public health in connection with the meat supply.

Contagious pleuropneumonia, introduced by Peter Dunn's cow, developed to such an extent that our export cattle and sheep were denied admission into Great Britain and were condemned to slaughter within a limited time on the docks where they landed. Our pork had been prohibited entrance into most of the markets of Europe.

That was the situation in 1883 when the Veterinary Division of the Department of Agriculture was established to meet the urgent needs for reliable, official information concerning the nature and prevalence of animal diseases and of the means required to control and eradicate them. Dr. D. E. Salmon was appointed chief of the new division, and a 7-acre farm was acquired to be used as an experimental station.

Much more was needed. Livestock men realized soon enough that an executive agency to carry into effect regulations to control and eradicate disease and to protect the growing animal industry at home and abroad had become even more necessary than the research work. Vigorous agitation and insistent demands for governmental assistance finally culminated in the act of Congress of May 29, 1884 "An act for the establishment of a Bureau of Animal Industry, to prevent the exportation of diseased cattle, and to provide means for the suppression and extirpation of pleuropneumonia and other contagious diseases among domestic animals."

THE ACT SPECIFIED that a competent veterinary surgeon should be chief of the Bureau, that the force should not exceed 20 persons at any one time, and that the Commissioner of Agriculture was authorized to appoint two competent agents who should be either practical stockraisers or experienced in livestock business matters. The sum of 150,000 dollars was appropriated to put the law into effect.

The wording of the act indicated that the first duty of the Bureau was to take charge of the eradication of pleuropneumonia in cooperation with the authorities of the States where the disease existed. Massachusetts and Connecticut had succeeded in eradicating the disease, but lack of laws, interest, and funds in other States had permitted the disease to spread from Long Island, where it appeared in 1843, into Pennsylvania, New York, New Jersey, Maryland, Virginia, West Virginia, and the District of Columbia by 1884. Reinfection occurred in Connecticut. Outbreaks in the Western States were reported in 1885.

It cost the National Government 5 years of work and 1,509,100.72 dollars to eradicate contagious pleuropneumonia from the United States. The United States was the first of the large countries to extirpate contagious pleuropneumonia. It was a signal achievement, especially in view of the doubts as to the possibility of eradicating the disease, the fact that the States were unprepared to cooperate effectively, the widespread opposition to "government interference," occasioned by the restrictions and temporary sacrifices experienced by individual owners, and the experiences of the other countries, which had labored a much longer time and made greater expenditures of money without success. Thus the new Bureau of Animal Industry accomplished its first undertaking.

Out of this first experience in disease eradication came an important lesson control of a contagious disease cannot be left to individual initiative. The clean herd of a good husbandman can be infected by his careless neighbor. A contagion does not stop at political boundaries. Only combined efforts at community, State, national, and international levels give us any degree of security against it.

Pleuropneumonia was only one of many problems. Although the slow boats that brought animals to this country were in one sense a floating quarantine, where many contagions ran their course before infected animals landed, many animal ills of the Old World had been imported with livestock. Anthrax, scab, the mange, blackleg, tuberculosis, the fowl plague, and pox were some of the more important ones. Tick fever had been imported, probably from the West Indies and Mexico. We also developed a disease of our own. Hog cholera appeared in Ohio in 1833 and by 1884 was a real killer.

To FIND THE CAUSE of tick fever was the next task of the Bureau of Animal Industry.

Tick fever probably entered this country as early as the 17th century by way of the West Indies and Mexico. By the 1860's trail herds from Texas ad brought pestilence and death to cattle in Indian Territory, Missouri, Kansas, and Arkansas.

Farmers were the first to suspect the cattle tick. Theobald Smith, the Bureau's first pathologist, began systematic experiments with tick fever in 1888. In 1 year he found the disease to be caused by a protozoan parasite in the blood of infected animals. Cooper Curtice, a Bureau zoologist, worked out the life cycle of the tick. F. L. Kilborne, working with Dr. Smith, tested the theory of the relation of ticks to the disease. Bulletin No. 1 of the Bureau of Animal Industry, issued in 1892, announced the momentous discovery that infection can be carried from one animal to another through the agency of an intermediate host the tick.

This first classic example of animal research cost 65,000 dollars. Today it saves farmers at least 60 million dollars a year. But even more important: The discovery unlocked the mysteries of such human diseases as malaria, yellow fever, typhus, bubonic plague, and Rocky Mountain spotted fever.