Contagious bovine pleuropneumonia (CBPP) is an insidious pneumonic disease of cattle sometimes referred to as lung sickness. Clinically, CBPP is manifested by anorexia, fever and respiratory symptoms such as dyspnoea, cough and nasal discharges. CBPP is found in the acute, subacute and chronic forms.
The disease is characterized by the presence of sero-fibrinous interlobular oedema and hepatization giving a marbled appearance of the lung in acute to subacute cases, and capsulated lesions (sequestra) in the lungs of some chronically infected cattle. Joint infections are common in calves.
The causative agent of CBPP is Mycoplasma mycoides subspecies mycoides small colony variant (MmmSC). Phylogenetically, the organism is a member of the Mycoplasma mycoides cluster which are pathogens of ruminants and include M. mycoides subsp. mycoides large colony (LC), M. mycoides subsp. capri, M. capricolum subsp. capripneumoniae, M. capricolum subsp. capricolum and Mycoplasma bovine group 7, an unnamed group of bovine mycoplasma isolates. The occurrence of subacute symptomless infections and chronic carriers after the clinical phase of the disease, create major problems in the control of this disease.