Fifteen cows in the Far East Primorye region are exhibiting symptoms of foot and mouth disease, Russian officials said, suggesting the illness was spreading.
Earlier this week, authorities said 123 head of cattle in a neighboring region, Khabarovsk, which borders on China, had the Asia-1 strain of the disease.
The chief of the Primorye branch of the veterinary monitoring agency, Vladimir Semenov, had said that the disease spreads on average by 120 to 150 kilometers (75 to 94 miles) every day.
Foot and mouth disease is a highly contagious viral illness that affects cloven-hoofed animals such as cattle, sheep and pigs. It causes sores, blisters and fever. It is deadly for livestock, but harmless to people.