Comparison of leptospiral infection in the horse and donkey

In order to compare the prevalence of leptospiral infection in horses and donkeys in Ahvaz, blood samples were taken from 61 horses and 90 donkeys. Sera were initially screened at dilution of 1:100 against 6 live serovars of Leptospira interrogans: Pomona, Canicola, Hardjo, Ballom, Icterohaemorrhagiae and Grippotyphosa using the microscopic agglutination test. The prevalence of leptospiral infection was 27.88% in horses and 40% in donkeys. Both the animal species had the highest titres to serovar Grippotyphosa (33.33% and 46.51%, respectively), followed in descending order by Ballom (23.81%), Pomona (14.28%), Canicula (14.28%), Icterohaemorrhagiae (9.52%), and Hardjo (4.76%) in horses and Icterohaemorrhagiae (23.25%), Ballom (13.96%), Pomona (9.30%), Hardjo (4.65%), and Canicola (2.33%) in donkeys. Statistical analysis showed significant difference between donkeys and horses (P<0.05). In horses there was relationship between infection and sex, so that females were infected more frequently than males but in donkeys this relationship was not seen. The prevalence of infection resulting from this survey is similar to those reported from other countries but there is difference in the predominant serotype. In addition, these results confirm that the majority of leptospiral infections is asymptomatic.