%0 Journal Article %T Frequency of seropositive equines for Theileria equi in the Southern Rio Grande do Sul State, Brazil %A LEANDRO QUINTANA NIZOLI %A MARCELO MENDES G£¿TZE %A SAMUEL RODRIGUES F¨¦LIX %A SERGIO SILVA DA SILVA %J Parasitolog¨ªa latinoamericana %D 2008 %I %X A study on equine theileriosis was carried out in the southern region of the Brazilian state of Rio Grande do Sul (RS). Blood samples were collected from 113 mares from an equine breeding farm located in the city ofBag¨¦, latitude 31 "30'S and a longitude of 54 U10' W. The serological testing was carried out with the use of indirect fluorescence test (IFAT) and compared with Nested Polimerase Chain Reaction (nPCR). Among the sera collected from 118 horses, 25 were found positive to Theileria equi by the IFAT, while by nPCR 17 positive for T. equi was observed, corresponding to a frequency of22.1%> and 15.0%, respectively. The racial analysis showed 15.05% (14) thoroughbred and 55% (11) Crioulo breed horses to be positive by IFAT. Foi realizado um levantamento sobre theileriose equina em uma propriedade da regi o sul do estado do Rio Grande do Sul (RS). Amostras de sangue foram coletadas de 108 ¨¦guas de um haras localizado no municipio de Bag¨¦, latitude 31¡ã30' Sul e longitude 54¨²10' Oeste. A sorologia foi realizada com o uso da imunofluoresc¨ºncia indireta (IFAT) e utilizou-se a t¨¦cnica de Nested Reac o em Cadeia Polimerase (nPCR). Do total de amostras examinadas, 22% (24) foram positivas por IFAT e 15% (16) por nPCR). Na an¨¢lise por raca, 15.05% (14) dos anim¨¢is Puro Sangue Ingl¨ºs (PSI) foram soro-positivos, e dos anim¨¢is da ra a Crioula (RC), 55% (11) foram positivos por IFAT. %K Theileria equi %K IFAT %K prevalence %U http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-77122008000100008