Here’s a look at mad cow disease, a deadly brain disease found in cattle.
It has been linked to a fatal brain disease in humans called variant Creutzfeldt-Jakob disease (vCJD).
The official name for mad cow disease is bovine spongiform encephalopathy (BSE). BSE lesions are characterized by spongy changes seen under an ordinary microscope.
Consumption of contaminated meat or other products from cattle (excluding dairy products) with BSE is thought to be the cause of vCJD.
BSE is transmitted from cow to cow through the practice of recycling bovine carcasses into meat and bone meal proteins, which are fed back into other cattle.
Mad cow disease and vCJD are deadly.
Symptoms of vCJD involve psychiatric symptoms and behavioral changes, movement deficits, memory impairment, and cognitive impairment.
BSE cases in North America from 1993 to August 2018: 26 confirmed cases, 20 in Canada and 6 in the United States. One of the dead infected cows in the United States was born in Canada. One of the infected Canadian cows was imported from the United Kingdom.
Since 1996, 231 cases of vCJD have been identified in 12 countries:
United Kingdom – 178
France – 27
Spain – 5
Ireland – 4
United States – 4
Italy – 3
Netherlands – 3
Portuguese – 2
Japan – 1
Saudi Arabia – 1
Taiwan – 1
1986 – Mad cow disease is first discovered in the UK. From 1986 to 2001, a UK epidemic affected around 180,000 cattle and devastated farming communities.
January 1993 – The BSE epidemic in Britain is reaching its peak with nearly 1,000 new cases reported per week.
1996 – The first case of vCJD is reported.
1996-1999 – The European Union bans British beef. France extends the ban for another three years.
May 20, 2003 – The first case of mad cow disease in Canada is confirmed in an 8-year-old cow in Alberta. Canadian officials say the cow did not enter the food chain.
May 21, 2003 – Mexico, Japan and South Korea join the United States in temporarily banning Canadian beef.
December 23, 2003 – The United States Department of Agriculture confirms the first case of mad cow disease in the United States. The infected cow was discovered on a farm in Washington State in early December. Japan, China and South Korea stop importing US beef. The infected cow was born in Canada in April 1997 – just four months before the United States and Canada began banning the use of brain and spinal cord tissue in cattle feed.
January 9, 2004 – The USDA says it will begin destroying about 130 cattle that were “herdmates” of the cow that tested positive for the first-ever US case of mad cow disease.
January 26, 2004 – New guarantees against mad cow disease are announced by the Food and Drug Administration. They include banning chicken waste in livestock feed and banning the use of restaurant meat scraps in animal feed.
January 28, 2004 – The Commodity Futures Trading Commission is launching an investigation into whether certain commodity futures market participants may have known of the first US case of mad cow disease before it was announced to the public.
June 20, 2004 – Charlene Singh, the first known person to live in the United States with vCJD, dies.
January 2, 2005 – Canadian health authorities confirm that test results have identified a 10-year-old dairy cow in Alberta as having mad cow disease. This is the second case of BSE in Canada in two years.
June 24, 2005 – The second American case of BSE is confirmed.
March 13, 2006 – The third US case of BSE is confirmed after an Alabama cow tested positive.
September 5, 2008 – Canadian scientists announce a discovery that paves the way for diagnostic testing on live cattle, rather than post-mortem.
September 13, 2008 – A research study from Alabama shows that mad cow disease can sometimes be caused by genetic mutations.
March 10, 2009 – According to a British medical study, an antimalarial drug known as quinacrine, which has shown promise against mad cow disease, has no effect on the disease.
March 14, 2009 – The The U.S. government permanently prohibits the slaughter of cows that are too sick or too weak to fend for themselves, seeking to further minimize the contraction of mad cow disease.
April 24, 2012 – The USDA confirms the fourth case of BSE, found in a dairy cow in central California. The ad maintains that the cow was never presented for slaughter for human consumption and poses no risk.
March 2014 – After 15 years, the United States lifts the embargo on beef from the European Union, pending inspections.
June 11, 2014 – USDA announces recall of 4,000 pounds of beef; a spokesperson cites “an abundance of caution”. The meat comes from the Fruitland American Meat processing plant in Jackson, Missouri.
March 24, 2016 – France confirms the first case of BSE since 2011.
October 18, 2018 – Scotland confirms that an “isolated case” of mad cow disease has been discovered on a farm in Aberdeen.