18-month-old spayed female Labrador Retriever
Presented for a grade 4/6 heart murmur first noted at 8 weeks of age. The murmur became worse after a canoeing accident in which she almost drowned. The fractional shortening was 42% (Normal range > 25%). The e point septal separation was 0.10 cm (<0.6 cm normal). The ratio of the left atrium to the aorta was 1.46 (<1.3 is normal). Velocity measured was 4.2 m/s with a pressure of 74 mmHg