Contagious Bovine Pleuropneumonia Pathology

The nature, cause, origin, and progress of Contagious Bovine Pleuropneumonia.

Contagious bovine pleuropneumonia (CBPP) is a slow–spreading, infectious disease of cattle, primarily affecting the lungs and joints.

CBPP is caused by Mycoplasma mycoides mycoides small-colony type (SC-type). M. mycoides mycoides large-colony type is pathogenic for sheep and goats but not for cattle. M. mycoides mycoides (SC-type) survives well only within a living animal and is quickly inactivated when exposed to normal external environmental conditions. The bacterial organism does not survive in meat or meat products and does not survive outside the animal in nature for more than a few days. Many of the routinely used disinfectants will effectively inactivate the organism.

Susceptibility
There are many reported breed differences with respect to susceptibility. In general, European breeds tend to be more susceptible than indigenous African breeds. The disease occasionally infects Asian buffalo. Humans are not susceptible to the disease.

Incubation Period
The time from natural exposure to overt signs of disease is variable but generally quite long. It has been shown that healthy animals placed in a CBPP-infected herd may begin showing signs of disease 20 to 123 days later. Experimentally, subsequent to instillation of large quantities of infective material at the tracheal bifurcation, the incubation period is 2 to 3 weeks. Infected cattle begin to breathe out bacteria during the incubation period - even before signs develop. Although not yet substantiated experimentally, it is thought that cattle that recover from CBPP may harbor a walled-off infection in their lungs; if stressed, the walls around the infection break down and the animal may become an active shedder of the organism again, and a source of infection, potentially showing no signs of disease.