Mycoplasmas are small fastidious wall-less bacteria which cause cause disease in all major species of animals including man. In small ruminants they can cause respiratory disease, mastitis, arthritis, genital disease and eye lesions. The most important of these diseases are contagious caprine pleuropneumonia (CCPP) and contagious agalactia (CA) which are designated by the Office of International Epizooties as List B diseases because of their  economic impact on the farming industry. Some of the mycoplasmas causing CCPP and CA are members of the "Mycoplasma mycoides" cluster which consists of six mycoplasmas, all of which are important pathogens of small and large ruminants.