Low livestock productivity in many developing countries is commonly considered to reflect, among other factors, the inadequate supply of services to control disease. Veterinary services have traditionally been provided by the state, but public finance constraints have limited the availability and effectiveness of public services. The author explains how economic theory can be used to identify alternative delivery systems (beyond the state) for providing animal health care and proposes new roles for the state and private sector in service delivery. The author highlights a number of barriers that currently limit the potential contribution of the private sector to service delivery, and describes a variety of approaches that have been used by the state to create an enabling environment for the private sector.