Johne's disease occurs in cattle and goats in south-eastern Australia while northern and western parts are considered to have little or no endemic disease. During the early 1990's, the Australian cattle industries initiated the development of a national program to reduce the spread and impact of Johne's disease. The result is the National Johne's Disease Market Assurance Program, developed and implemented by the industries, in partnership with State veterinary services. It aims to identify and classify herds with a low risk of being infected with M. paratuberculosis so that cattle buyers can source cattle with increasing confidence of not buying infected cattle. The program is being launched in 1996 and will be supported by research, training and advisory programs, standardization of diagnostic techniques, control programs in infected herds and rules for control of animal movements. Participation in the market assurance program is voluntary and at the cattle owners' expense. As such, it will be driven by market forces and will appeal to breeders who aim to procure a price premium or retain access to some markets. Herd owners will engage veterinarians, trained and approved for the program, who will be responsible for the herd's compliance with the program's management and testing requirements. Herds and approved veterinarians will be audited. Herds will progress through sequential Tested Negative, or Monitored Negative, status's following negative tests of all animals over 2 years of age, or of a sample of older animals, at intervals of from one to two years. Testing comprises screening by the absorbed ELISA and follow-up of reactors by fecal culture in herds with no previous history or by post-mortem investigation in herds in which Johne's disease had been previously suspected or known to occur. Cattle producers will be encouraged to seek a written and signed vendor declaration of a herd's Johne's disease status before buying cattle for restocking. Johne's disease has been confirmed in a small number of alpaca and is endemic in a small proportion of sheep flocks in areas in south-eastern Australia. Control and assurance programs are being developed.