Editing Paratuberculosis (section)

==Morbidity and mortality==
In an endemic herd, only a minority of the animals develops clinical signs; most animals either eliminate the infection or become [[asymptomatic]] carriers. The [[mortality rate]] is about 1%, but up to 50% of the animals in the herd can be asymptomatically infected, resulting in losses in production. Once the symptoms appear, paratuberculosis is progressive and affected animals eventually die. The percentage of asymptomatic carriers that develop overt disease is unknown.<ref>Paratuberculosis. In the Merck Veterinary Manual, 8th ed. Edited by S. E. Aiello. Whitehouse Station, NJ: Merck and Co. 1998.</ref>