First clinical identification of pseudo-lumpy skin disease in France

Since the first cases of lumpy skin disease (LSD) were observed in France on 29 June 2025, the measures implemented to limit the spread of this disease have proven effective in the two departments of Savoie in the French Alps. However, subsequent outbreaks in other close (Ain, Rhône, Jura) or remote departments (Pyrénées Orientales), as well as in Catalonia (Spain), show that we were not immune to the illegal movement of infected animals, transported to disease-free areas. The increase in suspected cases of LSD that tested negative, even in disease free geographical areas far from confirmed outbreaks, led to the first observation in France of pseudo-lumpy skin disease, which is caused by a herpesvirus and has a benign course that would not have alerted farmers outside the context of LSD.