Contagious Caprine Pleuropneumonia
Contagious caprine pleuropneumonia is a highly fatal disease that occurs in goats in the Middle East, Africa, and Asia. It was seen for the first time on European soil in Thrace, Turkey, in 2002, but does not appear to have spread to neighboring countries, Greece and Bulgaria. Outbreaks have recently been reported in sheep and captive wildlife, including gazelles and small ruminants.
Mycoplasma capricolum capripneumoniae (Mycoplasma biotype F38) is the causative agent. It appears to be transmitted by infective aerosol. Morbidity can be 100%, and mortality 60%–100%. The disease is introduced into a new region by healthy carriers. Gathering or housing animals together facilitates spread of the disease.
Pneumonia and pleuropneumonia can be caused by other mycoplasmas, including M mycoides capri. Taxonomic change means this subspecies also includes M mycoides mycoides large colony type. Morbidity and mortality rates are generally lower with M mycoides capri, and joint and udder infections may also be seen.
Weakness, anorexia, cough, hyperpnea, and nasal discharge accompanied by fever (104.5°–106°F [40.5°–41.5°C]) are often found. Exercise intolerance progresses to respiratory distress, with open-mouth breathing and frothy salivation. A septicemic form of the disease without specific respiratory tract involvement has been described.
Typically, there is an excess of straw-colored pleural exudate and acute fibrinous pneumonia. Consolidation is sometimes confined to one lung. The distention of interlobular septa by serofibrinous fluid, commonly seen in infections caused by M mycoides capri, is rarely seen in contagious caprine pleuropneumonia. In antibiotic-treated or recovered animals, the predominant lesion is a sequestrum similar to that seen in contagious bovine pleuropneumonia.
The clinical signs, epidemiology, and necropsy findings are used to establish a diagnosis. The causative organism should be isolated and identified, but isolation may be difficult, and special media is required for culture. PCR, which can be performed directly on the pleural fluid or affected lung, has greatly facilitated the diagnosis of contagious caprine pleuropneumonia. Serologic tests are complement fixation, passive hemagglutination, and ELISA; the latex agglutination test can be done in the field directly on whole blood as well as on serum samples in the laboratory. Serologic cross-reactions may occur with other members of the Mycoplasma mycoides cluster.