WASHINGTON (AP) - More cases of mad cow disease in Canada have halted U.S. plans for a major increase in Canadian beef and cattle imports, the Agriculture Department said Friday.
Canada has found seven cows infected with mad cow disease, four this year. Some were born after Canada took safety precautions related to cattle feed that should have prevented the animals from being infected.
The Bush administration was poised to resume imports of older cattle and beef from older animals.
But the department has halted those plans, which had been under final consideration by the White House, until an investigation into Canada's recent cases has been completed.
''We're committed to resuming normal trade with Canada and other trading partners based on scientific and international guidelines,'' Agriculture spokesman Ed Loyd said. ''But we also want to ensure that all the scientific information is taken into account in the development of those guidelines.''
Canada's most recent case was born in the spring of 2002, nearly five years after Canada erected its primary firewall against mad cow disease.
The firewall is a ban on ground-up cattle remains in cattle feed; the disease is believed to spread only when cattle eat feed containing diseased cattle tissue.
The U.S. imposed blanket restrictions against Canadian cattle and beef after Canada found its first case of the disease in May 2003.
In December 2003, an infected cow from Canada was discovered in Washington state; it became the first U.S. case of the disease.
Imports of beef from younger cattle resumed relatively quickly, but a court battle with a Western ranchers' group kept the border from reopening to live cattle until July 2005. Imports have been restricted to animals younger than 30 months, a cutoff set because infection is believed to spread with age.
Canada shipped $1.2 billion worth of beef and veal to the U.S. last year, according to the Agriculture Department. That amount totaled 368,540 metric tons, about 812 million pounds. That's about a quarter of the 3.6 billion pounds of beef imported last year.
In addition to meat, 544,858 cattle have been shipped to the U.S. from Canada this year.
Known medically as bovine spongiform encephalopathy, or BSE, mad cow is a brain-wasting disorder that infected more than 180,000 cows and was blamed for more than 150 human deaths during a European outbreak that peaked in 1993.
Humans can get a related disease, variant Creutzfeldt-Jakob Disease, by eating meat contaminated with mad cow.