Ovine contagious epididymitis: a review.

Ovine contagious epididymitis is predominantly associated with Brucella ovis, Actinobacillus seminis and a variety of organisms including Histophilus ovis. Transmission occurs venereally or by homosexual activity and, in the case of Actinobacillus seminis, ewe to lamb transmission is probably important. A chronic infection, mainly in the cauda epididymis may result in formation of spermatic granulomata and a reduction in ram fertility. Eradication of ovine brucellosis can be achieved by serological testing using a complement-fixation test in conjunction with palpation of lesions and removal of reactors. Vaccination to control ovine brucellosis is advocated in some countries. The nomenclature of the group of Gram-negative pleomorphic organisms to which Actinobacillus seminis and Histophilus ovis belong is urgently in need of review. This paper reviews the organisms capable of producing ovine contagious epididymitis, the pathogenesis of the condition as well as methods of diagnosis and control.