We reviewed the disease process in goats caused by Mycoplasma capricolum, M. mycoides subsp. mycoides, and M. putrefaciens and compared mycoplasma-infected goats (particularly young kids) for microanatomic changes. M. capricolum and M. mycoides subsp. mycoides cause a nearly identical disease: septicemia leading to pyrexia, high morbidity and mortality, interstitial pneumonia, arthritis (including polyarthritis), and mastitis. Until recently, M. putrefaciens was known only as a cause of mastitis. However, a new isolate of M. putrefaciens may be transiently septicemic, as evidenced by polyarthritis with isolations from joints, lung, brain, kidney, pleural fluid, uterus, and urine.