Animal diseases.

  • United States Department of Agriculture
Date:
[1956]
Catalogue details

Licence: Public Domain Mark

Credit: Animal diseases. Source: Wellcome Collection.

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    enough to be difficult to detect and stamp out. Complete eradication will first require the devising of new tech- niques, and studies along this line have been started. Other complications develop. Com- municable disease of livestock can be eradicated only when we prevent dis- eased animals from mingling with sus- ceptible ones. On the other hand, the freedom we have enjoyed from many diseases makes our cattle highly sus- ceptible should one of them strike. Then there are the problems gen- erated by increased numbers of ani- mals. Authorities in England have pointed out that disease problems are directly related to the increase in live- stock population. When animals dou- ble in number, disease problems in- crease by four times in a geometric progression that piles up troublesome crises faster than they can be resolved. Modern traffic in livestock accel- erates those troubles. Today’s live- stock producer must cope with many diseases to which his_ predecessor’s herds were not exposed. Modern transportation and marketing mingle livestock from different parts of the country and multiply the opportuni- ties for exposure. A steer these days may live in 3 or 4 States before he is slaughtered in Chicago. Mobility and mingling magnify problems of disease control. It took 15 years after hog cholera was first di- agnosed in 1833 for it to spread across the land. Some States remained free of the disease for 30 years. Tick fever of cattle moved across North Carolina at a rate of 4 miles a year in the 1870’s. But when vesicular exanthema of hogs broke out of California in 1952, the disease was diagnosed in 20 States within 3 months. So diseases of animals become more and more a concern of everyone, not merely the affected livestock owner. We have been working with hog cholera for 75 years, but only in 1956 did we reach a point where we could experimentally try to achieve com- plete eradication in an area. It is not merely a matter of giving medicines to an ailing animal. We need to pay even more attention, for example, to parasites, which take a heavy toll of the livestock industry. Many instances have been reported in which parasites are the main agents in causing outbreaks of disease. We need to control spectacular outbreaks, but frequently that pressing need de- lays the bringing of available resources to bear on the chronic, nonfatal dis- orders. Like mastitis, which causes an estimated 5-percent loss in total milk production, many do great damage. Other problems arise because new diseases arise. Some diseases just ap- pear. Often we do not know where they come from. Viruses, bacteria, and parasites are prolific, insidious, elusive, and_ in- visible. They strike suddenly, without warning. As livestock populations in- crease, as diseases and parasites cause new ravages, and as our standards of farm management rise, the -task be- comes bigger and more exacting. A livestock industry that can supply ~ an adequate amount of meat, milk, and eggs to maintain good diets for an increasing population is our heritage. An understanding of the threats to this capability that animal diseases present and maintaining ceaseless watch against them are our responsi- bility. M. R. CLarKson became deputy ad- ministrator of the Agricultural Research Service in 1952. A veterinarian, Dr. Clark- son has had long experience in the admin- istration of regulatory programs and in Federal-State cooperative activities. . He began his career in the Department of Agri- culture in 1930 as a veterinary meat inspec- tor. Among his assignments in the Depart- ment’s field service and in Washington. was work in the fight against foot-and-mouth disease in Mexico from 1947 to 1955. A native of Ferndale, Wash., he holds the degrees of bachelor of science and doctor of veterinary medicine from Washington State College and bachelor of laws from ews cee town University.