May 20, 2003: Canadian Food Inspection Agency announces a black Angus cow from northern Alberta has been found to have bovine spongiform encephalopathy. United States immediately closes its border to Canadian beef and cattle. About 40 countries follow suit.
June 17: Federal Agriculture Minister Lyle Vanclief announces a beef industry compensation package, cost-shared with provinces, of up to $460 million. A day later, he announces changes to slaughter rules: cattle tissues at high risk to carry BSE — notably brain and spinal cord — must be removed at the slaughterhouse from cattle older than 2.
Aug. 8: U.S. and Mexico partially lift ban on some Canadian beef products.
Dec. 23: U.S. Agriculture Secretary Ann Veneman announces the first U.S. case of mad cow — a Holstein in Washington state. About 30 countries eventually close their borders to U.S. beef. Canada imposes a partial ban.
Jan. 6, 2004: DNA tests confirm the Washington cow came from an Alberta herd.
Jan. 9: Bob Speller, successor to Vanclief as agriculture minister, announces $92 million will be spent over five years to increase mad cow testing.
Feb. 24: Statistics Canada reports farm income fell to its lowest level in three years in 2003 due in part to the mad cow crisis.
March 22: Prime Minister Paul Martin visits Alberta cattle country to announce an extra $995 million in mad cow aid. Two-thirds will go directly to cattle producers.
April 19: U.S. government changes import rules and begins accepting more beef products from Canada. It later reaches a deal with R-CALF USA, a protectionist cattle group, to halt imports of Canadian-processed beef products.
Nov. 29: Report from BMO's economics department says Canadian cattle producers have lost about $5 billion since the crisis began.
Dec. 29: U.S. announces plans to reopen the border March 7, 2005, to nearly all Canadian exports of beef and live cattle.
Dec. 30: CFIA announces that preliminary tests show BSE is suspected in a 10-year-old Alberta dairy cow. U.S. officials say the news won't change plan to reopen the border.
Jan. 2, 2005: Tests confirm dairy cow has BSE. American Meat Institute, a packers' lobby, sues U.S. Department of Agriculture to remove all restrictions on Canadian beef.
Jan. 11: Agriculture Minister Andy Mitchell confirms another case of BSE in Canada, again in an Alberta cow, probably due to contaminated feed. Officials say no part of the animal has entered human food or animal feed systems.
Jan. 13: Wilhelm Vohs, owner of latest Alberta mad cow, says he used commercial feed sold a year after federal rules banned ruminant parts in cattle feed.
Jan 14: Alberta Premier Ralph Klein says humans would have to eat billions of servings of bovine spinal cords, eyeballs and tonsils to get mad cow disease.
Jan 20: New research suggests proteins that cause BSE can be found in more tissues than previously thought.
Feb. 11: CFIA investigation into the last case of mad cow disease in Canada concludes that feeds manufactured after the national ban on parts in feed probably spread the disease.
Feb 25: Report by U.S. Agriculture Department technical team says Canada has robust inspection, overall compliance with feed ban is good and ban is reducing risk of BSE transmission in Canadian cattle.
March 2: U.S. judge slams shut the door to live Canadian cattle and expanded beef imports, granting R-CALF's request to postpone reopening the border.
March 3: U.S. senators voice fierce resistance to resuming cattle trade with Canada. Vote 52-46 to reject U.S. Agriculture Department's plan to start importing Canadian cattle.
March 7: Alberta, Saskatchewan and Manitoba pledge more money to help beef industry.
March 10: Ottawa kicks in $50 million for a campaign to reclaim and expand markets for Canadian beef.
March 11: The National Meatpackers Association files a long-shot emergency appeal with a San Francisco court to try to overturn a Montana judge's ruling that Canadian beef poses health hazards.
March 17: U.S. officials announce decision to appeal the court-imposed extension of the border closure.
March 29: Agriculture minister Mitchell announces that Canadian farmers will get $1 billion more in income support.
April 11: Canada's cattle producers file four class-action lawsuits accusing the federal government of negligence on the BSE file. Seek $7 billion in compensation.
April 12: Former inspector for the U.S Agriculture Department says his government is covering up mad cow disease. Lester Friedlander says he was fired from his job as head of inspections at a large meat-packing plant in Philadelphia in 1995 after criticizing what he called unsafe practices.
May 18: Alberta Agriculture Minister Doug Horner announces that province will require high-tech branding to verify age of all cattle slaughtered after March 2007.
June 29: Washington confirms a case of mad cow in a cow from Texas that was killed in November.
July 14: Federal appeals court in San Francisco overturns ban on Canadian cattle. Hours later, the U.S. agriculture secretary reopens border to live Canadian cattle.