A pet cow named Veronika can scratch her own back with a broom — the first scientifically documented case of tool use in cows, researchers say.

The idea of cows grazing in a pasture seems idyllic. We asked experts how their emissions stack up compared to factory farms.

© Photo by Ruth Fremson/The New York Times

Researchers are not just worried about the virus popping up on American farms. Other types are causing trouble around the world.

© Tim Gruber for The New York Times