Short communication Prevalence of Sarcocystis neurona and Neospora spp. infection in horses from Brazil based on presence of serum antibodies to parasite surface antigen Jessica S. Hoane a , Solange M. Gennari b , J.P. Dubey c , Ma ´rcio G. Ribeiro d , Alexandre S. Borges d , Lu ´cia E.O. Yai e , Daniel M. Aguiar b , Guacyara T. Cavalcante b , Ge ´rson L. Bonesi f , Daniel K. Howe a, * a Department of Veterinary Science, University of Kentucky, 108 Gluck Equine Research Center, Lexington, KY 40546-0099, United States b Faculdade de Medicina Veterina ´ria e Zootecnia, Universidade de Sa ˜o Paulo, Sa ˜o Paulo, SP, Brazil c United States Department of Agriculture, Agricultural Research Service, Animal and Natural Resources Institute, Animal Parasitic Diseases Laboratory, Beltsville, MD 20705-2350, United States d Faculdade de Medicina Veterina ´ria e Zootecnia, Universidade Estadual Paulista, Botucatu, SP, Brazil e Centro de Controle de Zoonoses, Prefeitura do Municı ´pio de Sa ˜o Paulo, Sa ˜o Paulo, SP, Brazil f Ministe ´rio da Agricultura, Pecua ´ria e Abastecimento, Delegacia Federal do Parana ´, Brazil Received 9 August 2005; received in revised form 10 October 2005; accepted 21 October 2005 Abstract Sera from 961 horses from Brazil were tested for antibodies against the major surface antigens SnSAG4 and NhSAG1 to determine the seroprevalence of Sarcocystis neurona and Neospora hughesi, respectively. Antibodies against SnSAG4 were detected in 669 (69.6%) of the horses, while antibodies against NhSAG1 were detected in only 24 (2.5%) of the horses. These serologic results suggest that there is a high concentration of S. neurona in the environment of Brazil, which results in marked exposure of horses to this parasite. Additionally, the data further confirm that infection with Neospora spp. is relatively uncommon in horses. # 2005 Elsevier B.V. All rights reserved. Keywords: Sarcocystis neurona; Neospora spp.; Seroprevalence; Horses; ELISA; Brazil 1. Introduction Equine protozoal myeloencephalitis (EPM) is a debilitating neurologic disease of horses that is caused by the protozoan parasites Sarcocystis neurona and Neospora hughesi (Dubey et al., 2001c; MacKay et al., www.elsevier.com/locate/vetpar Veterinary Parasitology 136 (2006) 155–159 * Corresponding author. Tel.: +1 859 257 4757x81113; fax: +1 859 257 8542. E-mail address: dkhowe2@uky.edu (D.K. Howe). 0304-4017/$ – see front matter # 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.vetpar.2005.10.023