DIAGNOSIS AND EPIDEMIOLOGY OF BRUCELLA-OVIS INFECTION IN RAMS

The relationship between clinical, serological and bacteriological dia gnostic criteria have been determined in Brucella ovis culture-positiv e and Brucella free control rams and also in 110 field rams belonging to 13 different flocks, in which an epidemiological survey was conduct ed. In control rams, a direct relationship was found among the existen ce of positive bacteriological results and the presence of a positive serological response in the gel diffusion (GD) and complement fixation (CF) tests for B. ovis. In field rams, the presence of macroscopic te sticular alterations (MTA) caused by B. ovis was correlated with bacte riological and serological results. The percentage of reactors and the percentage of rams showing MTA was not related to the size of flocks nor to the ratios of ram/ewes. The prevalence of B. ovis infection was significantly higher in rams from imported breeds than in those from local ones. Moreover, the younger and the oldest rams showed the lowes t prevalence of B. ovis infection, but the age of rams did not influen ce the prevalence of MTA not caused by B. ovis. (C) 1998 Elsevier Scie nce B.V. All rights reserved.