Symptoms, lesions and clinical evolution of Brucellosis in small ruminants

Abstract

Although brucellosis in small ruminants can be caused by Brucella abortus and B. ovis (sheep), B. melitensis is the major Brucella species involved in acute and chronic forms of this disease. Late abortions, stillbirths, weak neonates and epididymitis/orchitis are the main clinical signs. B. melitensis acute infections in pregnant females causes a macroscopic placentitis. In males necrotic epididymitis and orchitis can be observed. In the chronic form of the disease, the main clinical signs may not occur but the infected animals continue actively secreting B. melitensis into the environment and can infect other animals and man. B. abortus causes deterioration in the quality of the semen and acute edema and inflammation of the scrotum. Palpable lesions in the epididymis and tunicae of one or both testicles also can be observed. Usually, no clinical signs are seen in the ewe, but in some flocks, infection causes abortion, stillborn lambs or weak neonates. In infected lactating goats, mastitis due to B. melitensis can be a frequent occurrence instead of abortion.