Ultrasonographic findings in adult cattle with chronic respiratory disease

Modern portable ultrasound machines provide the veterinary practitioner with an inexpensive, non-invasive tool with which to examine the pleural surfaces and superficial lung parenchyma and help differentiate painful lesions in adult cattle that involve the pleurae (pleurisy, suppurative pneumonia), heart (pericarditis, endocarditis) and peritoneum (traumatic reticulitis, focal peritonitis). Systematic ultrasound examination need take the busy farm animal practitioner no more than 5 minutes. Ultrasonographic examination of the chest is most helpful in the definitive diagnosis of chronic suppurative pulmonary disease (CSPD) where there are numerous hypoechoic columns extending 2 to 6 cm into the lung parenchyma which are bordered distally by bright white (hyperechoic) lines as the transmitted sound waves contact normal aerated lung. Pleural effusion, present in many cases of dilated cardiomyopathy, thymic lymphosarcoma and diffuse fibrosing alveolitis is readily identified as an anechoic area which increases in depth as the probe head is moved ventrally with consequent dorsal displacement of the ventral margins of the lung lobes which may be consolidated. Pleural abscess(es) appear echogenically as an anechoic area containing many hyperechoic dots ("snowstorm appearance") allowing immediate differentiation from an effusion. In cattle with fibrinous pleurisy the visceral pleura appears thicker than normal and often displaced 2 to 3 cm from the parietal pleura by fibrin exudation of varying echogenicity. Metastases to the lungs are only imaged on the lung surface, appearing as discrete 2-3 cm diameter hypoechoic areas without a marked capsule, but are present throughout all lung lobes. Arcanobacterium pyogenes is the most common bacterial isolate from CSPD in adult cattle. Extended treatment with procaine penicillin is generally effective where lesions do not extend more than 5-10 cm above the level on the chest wall indicated by the point of the olecranon.