The presence of anti-Leptospira agglutinins in 1.360 samples of ovine sera was determined. Clinically healthy sheep with more than one year of age, raised in pasture in 136 farms of 18 counties, 10 located in the southeast Mesorregions and 8 in the southwest Mesorregions of the state of Rio Grande do Sul, Brazil, between the months of January and March of 1999. Were used sera tested by the Microscopic Agglutination Technique (MAT), from the 1.360 samples of serum tested, 466 (34.26%) were positive and the titers of anti-Leptospira spp. agglutinins varied from 100 to 3.200. The serovars founded were: hardjo (Norma), 210 (28.4%), sentot, 152 (16.8%); hardjoprajitno, 133 (14.5%); fortbragg, 73 (6.3%); wolffi, 39 (4.7%); pyrogenes, 25 (1.8%); australis, 21 (1.6%); pomona, 20 (1.6%); sejroe, 19 (2.2%); castellonis, 18 (1.8%); hebdomadis, 17 (1.3%); icterohaemorrhagiae, 16 (0.5%); grippotyphosa, 9 (0.7%); canicola , 8 (0.6%); tarassovi, 7 (0.6%), bratislava, 4 (0.29%), autumnalis, 3 (0.2%). The results demonstrate that Leptospira spp are disseminated in the majority of the farms that raise sheep in the southeast and southwest Mesorregions of the State of Rio Grande do Sul, Brazil.
leptospirosis; sheep; epidemiology; Rio Grande do Sul
