Agriculture. Lumpy skin disease: first outbreak confirmed in Ain

What is lumpy skin disease (LSD)?

LSD is a strictly animal viral disease that only affects cattle, buffalo, and zebu. It is not transmissible to humans, either through contact with infected cattle, or through the consumption of products from contaminated cattle, or through the bites of vector insects such as horseflies or stomoxys (biting flies).

If infection is confirmed, management measures for detected outbreaks involve depopulation of all cattle in the outbreak. Due to the characteristics of this disease, its contagiousness and its long incubation period (28 days according to the World Organisation for Animal Health), the eradication of LSD is only possible by applying total depopulation of cattle in the outbreaks, in addition to movement control and biosecurity measures (disinfestation of buildings and vehicles).

Even if they appear healthy, cattle in an infected group can silently carry the virus for several weeks. They can contribute to its transmission without it being able to be detected with certainty, even with laboratory tests. Depopulating the outbreak of only those animals showing symptoms carries a risk of spreading the disease.

Lumpy skin disease (LSD) in cattle was detected in France for the first time on June 29, 2025 in Savoie.

As of August 20, 2025, 75 outbreaks have been detected in France, spread across two departments: Savoie (31 outbreaks) and Haute-Savoie (44 outbreaks). These outbreaks concern 40 farms. The last one was detected on August 14.