It is inflammation of pulmonary parenchyma, usually accompanied by inflammation of bronchioles, and is characterized by cough, increased respiratory rate and abnormal lung sounds on auscultation.
Etiology: Pneumonia may be classified as (i) lobular pneumonia, (ii) lobar pneumonia, (iii) focal pneumonia, and (iv) interstitial pneumonia. Pasteurella multocida, P. hemolytica, Mycoplasma sp., Chlamydia sp., Streptococcus sp., Corynebacterium pyogenes, Mycobacterium bovis or M. tuberculosis, lung worm and bovine viral diarrhoea virus are the common causative agents.
Clinical signs: A bilateral mucopurulent nasal discharge may or may not be present depending upon the stage of pneumonia. There is rapid and shallow breathing. Bronchopneumonia is accompanied by moist rales and painful cough while interstitial pneumonia is accompanied by dry cough. In acute pneumonia there is increased body temperature. Dyspnoea may be either inspiratory or expiratory type. If there is severe pain it indicates pleuritis. Animal is anorexic. Chronic cases show depression and rough coat.
Diagnosis: Culture and drug sensitivity of nasal swabs gives an indication of bacterial involvement in pneumonia and the drug of choice for the treatment. White blood cell (WBC) count may be slightly elevated with shift to left in bacterial pneumonia. In acute viral pneumonia there is leukopenia and lymphopenia. Fibrinogen level is high in severe pulmonary diseases. X-ray of chest may be useful in the diagnosis.
Treatment: Selection of antibiotic for the treatment depends on the tentative diagnosis and drug sensitivity. Parenterally administered broad-spectrum antibiotic as well as parenteral and oral sulfonamides are effective in treating individual or herd cases. The affected animal should be kept in well ventilated warm room with provision of freshwater.