The history of bovine spongiform encephalopathy (BSE), also commonly named mad cow disease, began in the mid-1980s and even lingers today. Read the full article: The cow that stole Christmas – an oral history

Cooper david
Managing Editor / Progressive Cattle

Here were the key moments surrounding its spread and containment over four decades.


Cattle in the United Kingdom (U.K.) are diagnosed with a condition similar to scrapie in sheep, nicknamed “mad cow disease” due to behavior of sick cows. Scientists begin to suspect the feeding of rendered sheep meat infected with prions.


U.S. bans the import of cattle from countries where bovine spongiform encephalopathy (BSE) is known to exist in native livestock. 


U.K. bans feeding of meat and bone meal to animals and its use as farm fertilizer and begins tracking individual animals and testing any cow over 30 months old that is intended for human consumption.



The first three victims of a new variant Creutzfeldt-Jakob disease (vCJD), a fatal brain disease in humans, die in the U.K.

August 1997

The FDA bans protein made from cows, sheep, deer and other so-called ruminants used in feed for other ruminants. Spinal cord, brain and nervous system tissue are also banned from use in the cattle feed supply.

September 2001

The first outbreak of BSE occurs in Japan.

May 20, 2003

An 8-year-old cow in Alberta tests positive for BSE, the first confirmed case in North America. U.S. closes its border to Canadian cattle. The cow did not enter the food supply.

Aug. 8, 2003

U.S. and Mexico partially lift ban on some Canadian beef products.

Dec. 23, 2003

U.S. Secretary of Agriculture Ann Veneman announces a Holstein cow in Mabton, Washington, that originated from Canada tests positive for BSE. More than 30 countries close their borders to U.S. beef, including Japan, Mexico, South Korea and a partial ban from Canada. The cow was born in April 1997 – four months before the U.S. and Canada began banning the use of specified risk materials entirely from the food supply.

Dec. 30, 2003

The USDA bans sick and injured (“downer”) cattle from the human food supply, as well as specified risk material and tissues, such as brain and spinal cord, from cattle over 30 months old and mechanically separated meat.

January 2004

DNA tests confirm the Washington cow came from an Alberta herd.

New safeguards from FDA include banning chicken waste from cattle feed, as well as restaurant meat scraps.

Commodity Futures Trading Commission launches probe into whether some commodity market players knew of the first U.S. case before it was announced to the public. No illegalities are found.

March 2004

The USDA announces plan to test nearly 750,000 cattle annually for BSE. Mexico lifts ban on imports of boneless U.S. beef 30 months and under, but ban continues on live calves and cattle from U.S.

Dec. 29, 2004

U.S. announces plan to reopen its border to nearly all Canadian exports of beef and live cattle.

March 2005

U.S. judge in Montana District Court overturns USDA plan to allow live Canadian cattle and expanded beef imports, after a legal filing from R-CALF USA.

U.S. Senate rejects the plan to reopen the border to Canadian imports by a 52-46 vote. USDA officials appeal the court decision that kept border closure in place.

June 30, 2005

The USDA confirms a case of BSE in Texas, marking the first case from an animal that lived its entirety in the U.S.

July 14, 2005

U.S. 9th Circuit Court of Appeals overturns ban on Canadian cattle. Hours later, U.S. Secretary of Agriculture Mike Johanns reopens border to live Canadian cattle.

December 2005

Japan opens its borders to boneless U.S. beef aged 20 months or less after a two-year shutdown over BSE concerns.

January 2006

Japan again closes borders to U.S. beef imports just weeks after starting trade, when a veal shipment didn’t pass inspection.

July 2006

Japan lifts its ban on U.S. beef imports. Beef 20 months old and under and without specified risk materials is accepted.

July 2007

South Korea begins lifting restrictions on U.S. beef imports, but protests are staged by activists critical of the move with concerns of food safety and anti-American consumer groups. The ban goes back into effect over Korean concerns.

May 2008

South Korea’s new government led by Lee Myung-bak resumes a new campaign to allow U.S. beef into the country. The decision leads to protests in the hundreds of thousands in cities, known as the “Million Citizen Protests.” The staged protests continue through the summer.

June 2008

South Korean TV network MBC is criticized for its inaccurate reporting in a “PD Notebook” news broadcast mistranslating information about BSE from America and asserting vCJD’s presence in American beef. The erroneous reporting is cited as a cause for the Korean protests.

U.S. and Korea trade agreements proceed with amended terms limiting shipments to cattle 30 months or under (TMU) and certification of age, and Korean inspections of U.S. slaughter facilities.

Sept. 5, 2008

Canada announces discovery that leads to diagnostic testing of BSE in live cattle, rather than postmortem.

February 2013

The World Health Organization (WHO) upgrades the U.S. status for BSE to “negligible risk” – the highest status available, after USDA’s pattern of millions of BSE tests.

Japan extends access of U.S. beef imports to include beef products from cattle 30 months old.

June 5, 2014

Mexico lifts all regulations on U.S. cattle over 30 months old and all beef products from cattle of any age.

May 17, 2019

Japan and U.S. sign trade deal lifting all restrictions on U.S. beef products, regardless of age, eliminating age-based BSE testing.


  • Including the 2003 case in Washington, only six cases of BSE have been discovered in the U.S. and no cases detected in humans.
  • Canada had a total of 19 cases. The U.K. has experienced around 180,000, according to the National Institute of Health. 
  • Only three cases of vCJD have been documented in the U.S. Two individuals were originally from the U.K., and a third lived in Saudi Arabia.