The Republic of Ireland last week became the fourth European country to fall victim to the outbreak, which has already devastated Britain and spread to France and the Netherlands.
Fever is followed by the development of blisters, chiefly in the mouth or on the feet.
The disease is rarely fatal, except in very young animals. Nor is any one vaccine 100 percent effective against a single type. The disease now is confirmed in Argentina, where the government has been reluctant to undermine sales of Argentine beef on world markets after only recently overcoming an export slump related to an earlier outbreak of the disease. Argentine cattle industry leaders said the government knew about and hid the renewed outbreak until just last week. The Washington Post Foreign Service reported that Argentine ranchers and beef industry officials said authorities were aware of the outbreak at the end of last year and, largely in agreement with the meat industry, hid the problem, while continuing to export beef to the United States and other nations.