Small Animal Radiology and Ultrasound: A Diagnostic Atlas and Text

160 Small Animal Radiolo g y and Ultrasono graphy
Fig. 2-137 A and B, A 1-year-old
male cat with a 2-week history of
lethargy and anorexia. The cat had a
grade 4/6 holosystolic murmur. The
cardiac silhouette is enlarged
markedly. The ventrodorsal view
reveals marked biatrial prominence.
There is a small amount of pleural
fluid in the caudal mediastinum. A
pleural fissure line is present dorsal
to the cardiac silhouette (arrows).
The caudal vena cava appears
enlarged. The radiographic findings
are indicative of generalized cardiomegaly
with pleural fluid.
Diagnosis: Hypertrophic cardiomyopathy.
A
B
Hypertrophic cardiomyopathy is a relatively rare disease in the dog. 411 Breeding trials
have shown that a form of hypertrophic cardiomyopathy is heritable in Pointer dogs. 412
Many other breeds have had individuals that were affected. Radiographs rarely reveal significant
findings. In some individuals, left atrial enlargement may be noted.
Echocardiography usually reveals a global hypertrophy of the left ventricle. A muscular
ridge of tissue may be identified in the left ventricular outflow tract. Left atrial enlargement
and systolic anterior motion of the mitral valve also may be present.