Equine Brucellosis: Current Understanding and Challenges

•Brucellosis in equids is mainly caused by Brucella abortus and rarely by Brucella suis.•There is serological evidence of brucellosis in Equids worldwide.•Brucellosis in horses often manifest purulent localized lesions and rarely abortion.•Detection of anti-Brucella antibodies are widely used to diagnosed equine brucellosis.•Treatment of brucellosis in equines is not usually performed or recommended. 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.