OTTAWA -- Canada has found what may be a second case of mad cow disease, officials said Thursday, just a day after the United States said it planned to reopen its border to Canadian beef.
The border was closed 19 months ago when a cow in northern Alberta tested positive for mad cow disease, or bovine spongiform encephalopathy (BSE). The U.S. Department of Agriculture said Wednesday the border could be opened in March.
The Canadian Food Inspection Agency released few details on the new suspect case, except to identify it as a 10-year-old dairy cow.
The preliminary testing results were completed on Wednesday, said the agency, adding that the testing was conducted after the cow was identified as a "downer" -- unable to walk.
The finding is not definitive, but the Canadian agency says multiple screening tests have yielded positive results. No part of the animal entered the human food or animal feed systems, said the agency.
Samples are currently being analyzed at the Canadian Science Center for Human and Animal Health in Winnipeg, Manitoba, and confirmation is expected in three to five days.
The CFIA said U.S. authorities have been notified of the tests and added that the government's normal policy is to report only confirmed results.
"However, given the unique situation created by the United States' border announcement . . . it was decided that the most prudent action would be to publicly announce the available information and provide stakeholders with a full understanding of the current situation," said the CFIA.
The new U.S. policy announced Wednesday will permit imports of cattle younger than 30 months and certain other animals and products from Canada, which the Agriculture Department said has effective measures to prevent and detect mad cow disease.
The department said the ruling, which will take effect March 7, came after determining Canada is a "minimal-risk region," the first country recognized as such.
Since confirming BSE in Canada in 2003, CFIA officials have stated that finding more cases in North America was possible.
Dennis Laycraft of the Canadian Cattlemen's Association said Thursday he expected the border to reopen on schedule because the finding, if positive for BSE, would still fall within U.S. guidelines maintaining Canada as a minimal risk country.
"It's a little unbelievable in terms of the timing within a few hours of the U.S. announcement," Laycraft said. "But early indications are that things will continue to move ahead."
BSE is a chronic, degenerative disorder affecting the central nervous system of cattle. Since it was first diagnosed in Great Britain in 1986, there have been more than 180,000 cases.
Before the trade ban, animals regularly crossed the border and Canada sold more than 70 percent of its live cattle to the U.S. That market was worth US$1.5 billion in 2002.