Mitral Valve Stenosis

Heart valve disease is a condition in which one or more of the heart valves don't work properly. The heart has four valves: the tricuspid, pulmonary, mitral, and aortic valves. These valves have tissue flaps that open and close with each heartbeat. The flaps make sure blood flows in the right direction through the heart's four chambers and to the rest of the body.

Mitral valve stenosis is a narrowing of the mitral valve opening caused by abnormalities of the mitral valve. This obstructs blood inflow to the left ventricle. The defect is rare in dogs and is most often seen in the Bulldog, Chihuahua, Great Danes, Keeshond, and Cavalier King Charles Spaniel. It can occur together with other congenital defects such as subaortic stenosis, mitral valve dysplasia, and pulmonic stenosis.

Congenital Mitral Valve Stenosis

Congenital mitral valve stenosis occurs infrequently in dogs often in association with subaortic stenosis. Newfoundlands and bull terriers appear predisposed.² Other large breed dogs are also affected, such as German Shepherd dogs, Labrador Retrievers, Old English Sheepdogs, and Great Danes.³

Birth defects, age-related changes, infections, or other conditions can cause one or more of the heart valves to not open fully or to let blood leak back into the heart chambers. This can make the heart work harder and affect its ability to pump blood.

Signs of Mitral Valve Stenosis

Loss of consciousness due to lack of blood flow to the brain occurs in some dogs with these defects.

Treatment of Mitral Valve Stenosis

Dogs with mitral stenosis may be prescribe diuretics (to help eliminate fluid buildup) and put on a low-salt diet. Diuretic use need to be carefully monitored by a veterinarian because it can cause excessive urine output, which may severely reduce blood flow from the heart. Surgery and other treatments are rarely performed because they involve both considerable risk for the animal and high cost.

References

1. Cynthia M. Kahn, Scott Line. The Merck/Merial manual for pet health
2. John K. Dunn. Textbook of small animal medicine
3. Mike W. S. Martin, Brendan M. Corcoran. Notes on cardiorespiratory diseases of the dog and cat

Related Topics

• Aortic Stenosis
• Atrial Septal Defect
• Central Core Myopathy
• Bacterial Endocarditis
• Circulatory Disorders
• Conotruncal Heart Malformation
• Cor Triatriatum Dexter.aspx
• Dilated Cardiomyopathy
• Endocardial Fibroelastosis
• Familial Thoracic Aortic Aneurysm
• Heart Failure
• Heart Muscle Diseases
• Heart Valve Diseases
• Mitral Valve Stenosis
• Polymicrogyria and Asymmetrical Ventricular Dilation
• Pulmonic Stenosis
• Subaortic stenosis
• Tachycardia
• Tricuspid Valve Dysplasia
• Endotoxin Shock
• Veterinary Drugs