The Swiss veterinary authorities have registered the first case of bluetongue disease in the country, after cows were infected near Basel.
The illness, which is not considered dangerous for humans but can devastate animal herds, has spread from Germany and France and is affecting much of northwestern Europe.
The Federal Veterinary Office announced on Sunday that six of 19 animals in a herd had tested positive for bluetongue. One cow presented severe symptoms and was put down.
Patrick Gerber, whose farm sits north of the Rhine, told Swiss television that it was obvious that something was wrong with some of his animals on Thursday.