J. Cauchard , D. Carnicer , A. Madeline , E. Guitton , A. Giraudet , P. Buscher , L. H ebert , C. Laugier 1 ANSES, Dozul e Laboratory for Equine Diseases, Bacteriology and Parasitology Unit, 14430 Goustranville, France; 2 Institut National de Recherche Agronomique, Tours, France; 3 Ecole Nationale V et erinaire d’Alfort, Maisons Alfort, France; 4 Institute of Tropical Medicine, Department of Biomedical Sciences, Nationalestraat 155, B-2000 Antwerp, Belgium