Small Animal Radiology and Ultrasound: A Diagnostic Atlas and Text

130 Small Animal Radiolo g y and Ultrasono graphy
Fig. 2-103 A 5-month-old female Airedale brought for evaluation
of a grade 5/6 holosystolic murmur. The cardiac silhouette is
enlarged. A, On the ventrodorsal radiograph the right margin of
the cardiac silhouette is rounded. A bulge is present in the area of
the pulmonary artery segment (arrows). B, On the lateral radiograph
there is increased sternal contact and cranial bulging of
the cardiac margin. The pulmonary artery enlargement is also evident
cranial to the cardiac silhouette (arrows). The pulmonary
vessels appear small. The radiographic findings are indicative of
right heart and main pulmonary artery segment enlargement.
Diagnosis: Pulmonic stenosis.
A
B
Left Atrial Enlargement. On the lateral radiograph, the silhouette of the enlarged left atrium
produces a wing-shaped shadow caudal to the tracheal bifurcation and dorsal to the caudal
vena cava (Fig. 2-104). The caudal cardiac margin becomes straight and forms a sharp angle
with the dorsal cardiac margin, with loss of the caudal cardiac waist. Caudal to the tracheal
bifurcation, the main stem bronchi are elevated, the left more markedly than the right.