It is the acute or chronic inflammation of the pleural membranes. It is characterized by pain during respiration, pleural effusion, and shallow rapid respiration.
Etiology: It is associated with pneumonia, pulmonary abscess, peritonitis and penetrating wounds of the chest wall. Pasteurella multocida, P. hemolytica, M. bovis, M. tuberculosis, and Mycoplasma (contagious bovine pleuropneumonia) are some of the causes of pleurisy in cattle and buffaloes.
Clinical signs: There is rise in body temperature in early stage of the disease. Loss of appetite, rapid and shallow respiration, dyspnoea with depression is observed. Abducted elbows and abdominal respiration may be seen. Animal is not inclined to move. In chronic stage, there is weight loss, intermittent fever and reduced exercise tolerance test. Frictional rubs may be heard on auscultation. There is dullness over the fluid filled area of thorax. Pleuritic ridge is evident at the costal arch. Pain is evident on palpation in the intercostal spaces. Cough is painful, short and shallow. Extension of the inflammation to the pericardial sac is also present. Death is due to anoxia and toxemia.
Diagnosis: Thoracocentesis can be performed for laboratory examination. Fluid may be examined for colour, odour, viscosity, protein, blood and cells. Fluid may also be examined for aerobic and anaerobic bacteria. A foul odour of the pleural fluid and presence of gas bubbles indicate anaerobic organisms. Radiography of the chest is also suggested. Haematological investigations may not be specific and may indicate inflammatory process. Leukocytosis and increase in the protein concentration of pleural fluid may be seen in pleurisy.
Treatment: Prognosis of pleurisy is mostly unfavourable in the farm animals as disease is diagnosed quite late. Antibiotics, anti-inflammatory drugs and analgesics are helpful. Antibiotics may directly be administered in the pleural sac. Dexamethasone can be used to reduce the degree of pleural effusion. Pleural effusion once formed, may reduce the chances of recovery of animal.