Affected animals normally have generalised signs such as depression, dullness, weakness and lethargy,
pyrexia and weight loss and decreased production. They will also have respiratory signs including bilateral nasal discharge,
dyspnoea,
tachypnoea and
coughing. Occasionally the only sign seen is sudden death. Typical pathological lesions are very suggestive of the disease – they are localised exclusively to the
lung and
pleura. Lungs are normally a port wine colour and abundant pleural
exudate and
pleuritis and adhesions are common. The pleural exudates may have solidified forming a gelatinous covering. Histological examination of the lung tissues may show acute serofibrinous to chronic fibrino-necrotic pleuropneumonia with neutrophilic inflammation in the
alveoli,
bronchioles, interstitial septae and subpleural connective tissue. ==Diagnosis==