West Nile Virus Spreads Among German Horses Amid Rising Insect Activity

A mild, wet winter in Germany has created ideal conditions for mosquitoes and ticks, leading to a notable increase in insect populations around stables and pastures. The surge has coincided with the spread of West Nile virus, a disease originally from Africa that first appeared in European birds in the 1960s and was detected in German birds in 2018.

Since then, the virus has been confirmed in horses, with recent cases reported in southern Lower Saxony. While many infections in horses are asymptomatic, about eight percent develop severe neurological symptoms such as fever, ataxia, weakness, tremors and, in some cases, paralysis. Mortality among severe cases can reach up to 50 percent, and survivors may suffer lasting effects. In response, an increasing number of horse owners are opting for prophylactic West Nile vaccination.

The German Weather Service (Deutscher Wetterdienst) has recorded unprecedented rainfall—approximately 1,000 L per square metre over the past year—further supporting the proliferation of disease‑carrying insects.