Small Animal Radiology and Ultrasound: A Diagnostic Atlas and Text

138 Small Animal Radiolo g y and Ultrasono graphy
FIG. 2-109 A 9-month-old female
Cocker Spaniel was brought in for
evaluation of a continuous murmur.
The cardiac silhouette is markedly
enlarged. A, On the lateral radiograph
the cranial and caudal cardiac
margins appear rounded, and a
soft-tissue density is present in the
area of the left atrium (arrows). B,
On the ventrodorsal radiograph
there are bulges on the left cardiac
margin at the site of aorta (a) and
left atrium (l). The cardiac apex is
rounded. The pulmonary vessels
appear increased in size. The radiographic
findings indicate left-sided
cardiomegaly with pulmonary arterial
and aortic aneurysmal dilations.
The increased size of pulmonary vessels
indicate the presence of a left-toright
shunt. Diagnosis: Patent
ductus arteriosus.
A
B
ventrodorsal radiograph along the left side of the aorta at the level of the fourth or fifth
intercostal space. Additionally, a pulmonary arterial aneurysmal dilation or knob often is
visible at the same level or slightly caudal to the aortic aneurysm, and a third bulge representing
an enlarged left atrial appendage may be visible caudal to the pulmonary
aneurysm.