Equine Brucellosis: Current Understanding and Challenges.

Brucellosis in equines, including horses, donkeys, and mules, is characterized by abscesses in tendons, bursae, and joints. Reproductive disorders, which are common in other animals, are rare in both males and females. Joint breeding of horses, cattle, and pigs was found as the main risk factor for equine brucellosis, with the transmission from equines to cattle or among equines possible, although unlikely. Hence, evaluation of the disease in equines can be considered an indirect indicator of the effectiveness of brucellosis control measures employed for other domestic species. Generally, the disease in equines reflects disease status in the sympatric domestic species, mainly cattle. It is important to note that in equines, the disease has no validated diagnostic test, which limits the interpretation of available data. Finally, it is important to mention that equines also represent significant Brucella spp. infection sources for humans. Considering the zoonotic aspect of brucellosis, the significant losses due to infection, and the representativeness of horses, mules, and donkeys in the society, as well as the continuous efforts to control and eradicate the disease in livestock, in this review, we covered the various aspects of brucellosis in equines and compile the sparse and diffuse information on the subject.

Brucellosis in working equines of cattle farms from Minas Gerais State, Brazil.

The present survey aimed at estimating the seroprevalence of brucellosis in working equines of cattle farms from Minas Gerais State, Brazil, and investigating risk factors associated with the infection. Serum samples from 6439 animals, including 5292 horses, 1037 mules and 110 donkeys, were collected from 1936 herds, between September 2003 and March 2004, in 848 municipalities from the state of Minas Gerais, Brazil. The prevalence of antibodies against smooth Brucella spp. found in equines from Minas Gerais State was 1.37% (95% CI: 0.97-1.78), resulting in a prevalence of herds with infected animals of 4.28% (95% CI: 4.21-4.36). There were differences between regions but these were not of major epidemiological relevance nor were most of them statistically significant, given the considerable overlap of confidence intervals. Nevertheless, the point estimates suggest that the three northeastern regions have slightly higher prevalence than the rest of the state, both at the herd and animal levels. No association of Brucella spp. seropositivity with sex, age or host was observed. In conclusion, the present study showed a low but widespread prevalence of antibodies against smooth Brucella in equines kept in cattle farms in Minas Gerais, a state where bovine brucellosis is also widespread albeit with low prevalence.