829
edits
Changes
→Diagnosis
==Diagnosis==
==Diagnosis==
===Diagnostic Tests===
===Diagnostic Tests===
Hematological and biochemical analysis of blood samples may be useful to diagnose several underlying causes for acquired megaoesophagus, such as myositis with an elevated creatine kinase (CK) concentration.
===Diagnostic Imaging===
===Diagnostic Imaging===
Most cases of megaoesophagus can be diagnosed on '''plain radiographs of the chest'''. The following features may be observed:
*A large radiolucent structure dorsal to the trachea on lateral radiographs, but it should be noted that it is normal for the oesophagus to contain air if the animal is under general anaesthesia.
*The tissue between the trachea and oesophagus may be compressed producing a radio-opaque '''tracheal stripe sign''' along the dorsal surface of the trachea on a lateral radiograph. The trachea may also appear to deviate ventrally. On a dorso-ventral radiograph of the chest, the trachea may be pushed to the right by the enlarged oesophagus.
*Chronic regurgitation increases the risk of developing '''aspiration pneumonia'''. If it is present, it produces an alveolar pattern in the cranial and ventral lung lobes.
*With vascular ring anomalies, the oesophagus is usually only dilated cranial to the base of the heart.
The presence of megaoesophagus can be confirmed by feeding '''barium contrast medium''', either as a liquid or mixed with meat (a 'barium meal'). The advantage of the barium meal is that it distends the oesophagus (to show the extent of its dilation) and it provides better definition of the point of constriction in animals with a vascular ring anomaly.
'''Endoscopy''' allows the operator to visualise the dilated oesophagus directly but this is rarely required to reach a diagnosis.
==Treatment==
==Treatment==