Prevalence of Besnoitia besnoiti infection in beef cattle from the Spanish Pyrenees.

Reports of recent outbreaks of bovine besnoitiosis in Europe have emphasized the need for prevalence studies to determine the importance of the disease. A previous cross-sectional study carried out in a northern province of Spain showed that seropositive cattle were beef breeds primarily located in regions where the disease is endemic (such as in the Pyrenees). The present study focused on this population. Sixty-three beef herds were selected and at least 50% of the animals in each herd were sampled (n = 3318). The herd, intra-herd and animal prevalence rates were calculated. All breeding bulls located in the same region were also sampled (n = 587), and the animal prevalence calculated. Sera were tested by ELISA. The herd prevalence rate of bovine besnoitiosis was 87.3%, and both sexes were similarly affected (approximately 50%). The results indicate that the disease is highly widespread in the Pyrenees, and that serological examination of cattle should be recommended when trading beef cattle.