Mad cow disease, or bovine spongiform encephalopathy (BSE), is a fatal brain disorder that occurs in cattle.

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To the cattle industry, an outbreak of mad cow disease is an ever-looming nightmare. In the 1980s and '90s, the brain disorder infected 180,000 livestock in Europe and claimed dozens of human lives, devastating the British cattle industry. Britain, the United States and most other major cattle-producing nations have imposed stringent measures to control the disease, but another outbreak is a very real possibility.

In this article, we'll discuss what mad cow disease is, how it works, what the consequences for humans are and what is being done to control and prevent its occurrence.