Mitral Valve Dysplasia in Dogs

Category: Heart
Breeds documented: 1
Published sources: 3

Overview

When the mitral valve develops abnormally before birth, it may fail to close properly. Blood can leak backward instead of moving forward through the heart. Over time, this can enlarge the left side of the heart. Severe leakage may lead to fluid in the lungs and an irregular heartbeat. The severity of the defect varies between affected animals.

Signs to watch for

Coughing
Difficulty breathing
Weakness
Fainting

The defect is present from birth; mild cases may show no signs for years.

Emergency Go to an emergency vet now if your dog has difficulty breathing.

Diagnosis and tests

A vet may first suspect the problem after hearing a heart murmur. An ultrasound examination of the heart shows the malformed valve and checks for backward blood flow. Chest X-rays can reveal heart enlargement or fluid in the lungs, while an electrocardiogram records abnormal heart rhythms.

Breeds with documented risk

1 breed

By breed size

1 Medium

Bull TerrierMedium · Terrier Group

Inheritance

Not yet known
None of the sources we use states how this is inherited in dogs yet.

We've gathered what published sources say about this condition, so you can talk it through with your vet. It isn't veterinary advice: you and your vet know your dog best.