Contagious agalactia of small ruminants is a syndrome which affects mainly the mammary glands, joints and eyes. The principal causal agents are Mycoplasma agalactiae in sheep and M. agalactiae, M. mycoides subsp. mycoides large colony type and M. capricolum subsp. capricolum in goats. In addition, M. putrefaciens can produce a similar clinical picture, particularly in goats. Contagious agalactia occurs on all five continents and is often enzootic. These infections are chronic in animals and in flocks. Symptomless shedding of mycoplasmas, mainly in the milk, may persist for a long time. Associated with carriage in the ears of healthy animals, these insidious infections are difficult to diagnose and control. The sale of carrier animals and contact during transhumance are the main modes of transmission between flocks, while transmission within a flock occurs through contact, suckling and milking. This review discusses clinical features, epidemiology, treatment, prevention and control.
