Page 133 - Problem-Based Feline Medicine

9 – THE CAT WITH ABNORMAL HEART SOUNDS AND/OR AN ENLARGED HEART 125

● Diaphragm.
● Thoracic skeleton.
WHAT?
● Most cats with heart murmurs are not symptomatic for heart disease.
● The most common form of acquired heart disease in cats is hypertrophic cardiomyopathy.
● Some cats with cardiac enlargement have normal physical exam findings.

QUICK REFERENCE SUMMARY
Diseases causing abnormal heart sounds and/or an enlarged heart
DEGENERATIVE

● Valvular endocardiosis (p 155)
A murmur localized to the left sternal apex is heard. It is a rare disease of old cats. Some cats may
present with congestive heart failure.
ANOMALY
● Ventricular septal defect* (p 140)
A congenital systolic murmur is heard which is loudest over the right sternal border. Most cats are
asymptomatic.

● Patent ductus arteriosus (p 142)
A congenital continuous murmur loudest over the left cranial thorax is heard. A palpable thrill is
usually present. It is more common in Siamese and Persian cats.

● Tetralogy of Fallot (p 149)
A systolic murmur is heard over the left cranial thorax (pulmonic area). A split second heart sound
may also be found. Cyanosis is usually present.
● Atrial septal defect (p 144)
A breed predilection in Persian cats is reported. A systolic murmur over the left cranial thorax is
heard.
● Mitral valve dysplasia/stenosis (p 145)
This is the most commonly encountered congenital valvular malformation and is associated with a
systolic and/or diastolic murmur over the left cardiac apex.
● Aortic stenosis (p 146)
Aortic stenosis is associated with a systolic murmur over the left aortic area. There is an increased
incidence in Siamese cats.
● Pulmonic stenosis (p 148)
Pulmonic stenosis is associated with a systolic murmur over the pulmonic area and is usually seen
with other defects.
● Tricuspid dysplasia
Tricuspid dysplasia is associated with a low-frequency systolic murmur over the right thorax.

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