Contagious agalactia is a mycoplasmal disease of sheep and goats that can cause serious economic losses from mastitis, polyarthritis and keratoconjunctivitis. In lambs and kids, losses due to septicemia and pneumonia can be high. Some outbreaks may affect most of the animals on a farm. Mycoplasma agalactiae is the main cause of the disease in sheep and goats, but M. capricolum subsp. Capricolum, M.mycoides subsp. capri and M. putrefaciens produce a clinically similar disease, more often in goats, which may be accompanied by pneumonia.