Bovine Spongiform Encephalopathy

Only a British Concern?

Abstract

Between November, 1986, and August, 1991, 35,100 clinical cases of bovine spongiform encephalopathy (BSE) were confirmed histopathologically by the staff of the Central Veterinary Laboratory (CVL) Ministry of Agriculture, Fisheries and Food in Weybridge, England. It is not known how many cases of BSE went unreported during this time period, but informal estimates range from several hundred to several thousand. These losses occurred within the prime production population of the United Kingdom's dairy and beef herds which number approximately four million adult animals (twelve million total cattle) in a geographic area approximately the size of Oregon. During the same period, novel spongiform encephalopathies were confirmed in nine zoo animals of various species, but all from the family bovidae. Also, spongiform encephalopathy was confirmed in nineteen domestic cats during the last sixteen months, and BSE was identified in native-born dairy cattle in Switzerland (7 cases confirmed) and France (4 cases confirmed) during the past ten months.

The advent of a novel, progressive, and transmissible spongiform encephalopathy in cattle and its rise to epidemic levels in the United Kingdom has caused substantial economic hardship for the dairy, beef, and rendering industries of that country. In addition, it has led to increased public concern about the quality of agricultural products in general and the effectiveness of the government agencies that regulate the production and consumption of those products. These concerns have been transmitted internationally such that a recurring question in Europe and the Americas is "Can BSE happen here?". A simple answer to this question is not available, but awareness on the part of U.S. bovine practitioners of the disease characteristics and the factors that contributed to the problem in the U.K. will help prevent a BSE-like epidemic from occurring in the United States.