First documented cases of equine leishmaniasis caused by Leishmania (Mundinia) martiniquensis in France

Abstract

In this study, we describe the first documented cases of equine cutaneous leishmaniasis caused by Leishmania (Mundinia) martiniquensis in France and provide clinical and parasitological data relevant for the recognition of this emerging infection in horses. Three horses presenting localized cutaneous lesions were diagnosed with L. martiniquensis infection in different regions of France without spatial or temporal clustering. Lesions were clinically nonspecific and initially compatible with common equine dermatological conditions, including sarcoid-like tumors. Histopathological examination revealed granulomatous dermatitis with intrahistiocytic organisms morphologically consistent with Leishmania amastigotes in all cases. Molecular analysis of formalin-fixed paraffin-embedded tissue confirmed the presence of Leishmania DNA, and sequencing of the ITS1 locus identified L. martiniquensis. Direct agglutination test serology was negative in two horses and strongly positive in one. In one case, parasite isolation was achieved in culture. The disease remained localized in all animals, with spontaneous regression in one case, resolution following surgical excision in another, and complete healing after intralesional treatment with meglumine antimoniate in the third.