The Agriculture Department plans to test 5,000 to 10,000 Washington state cattle for mad cow disease as part of a $70 million effort to find out whether the infection is present in the United States and, if so, at what level.

The one-time, intensive program, which begins Tuesday, aims to test at least 220,000 animals nationwide over the next 12 to 18 months.

Agriculture Department officials say they would not be surprised to find a small number of cattle infected with bovine spongiform encephalopathy (BSE), the scientific name for the disease first detected in the United States in December in a cow slaughtered near Yakima, Wash.

"It's important to acknowledge that, in fact, it is possible we will find an additional BSE-positive cow," W. Ron DeHaven, the agency's chief veterinarian, said last week.

Relying on rapid tests that give results in 24 hours or less, the new program will screen more than 10 times the number of animals tested in 2003. The expanded testing program will examine less than 1 percent of the 35 million cattle slaughtered in the United States each year. But DeHaven said it will target the animals most likely to carry the disease and should be able to detect the disease at a level of one case in 10 million cattle.