Tricuspid Valve Dysplasia

Tricuspid Valve Dysplasia (TVD) is one of the many pathological conditions involving any of the various heart valves. Heart valves are flaps of tissue that prevent regurgitation of blood from the heart ventricles to the heart atria or from the pulmonary arteries or aorta to the ventricles. A tricuspid valve is a valve consisting of three cusps situated between the right atrium and right ventricle of the heart.

In tricuspid valve dysplasia, valves can become too thick or short. The malformed valve does not close tightly and allows regurgitation of blood back into the right atrium.

This defect occasionally is seen in dogs at birth. Breeds most likely to have this condition are German Shepherds, Great Danes, Old English sheepdog and Labrador Retrievers. Other defects of the heart may also be observed in affected dogs such as atrial septal defect or malformed mitral valve complex.

The blood leaking from the valve into the right atrium causes the right side of the heart to enlarge. TVD can be mild to severe. Puppies with mild TVD can live somewhat normal lives, but puppies with severe TVD will die before they are one year of age as the condition often results in congestive heart failure with clinical signs that include rapid breathing, exercise intolerance, and bluish coloration of mucous membranes and gums.

Treatment of Tricuspid Valve Dysplasia

Treatment is aimed at the signs of congestive heart failure and is similar to treatment for chronic valve disease seen in adult dogs. Surgical correction or valve replacement may be available in the future. Anti-arrhythmic drugs may become necessary in cases of irregular heart beat.

In Labrador Retrievers, TVD is a heritable disorder. Affected dogs and dogs closely related to affected dogs should not be used for breeding.

References

1. Mike Martin, Brendan Corcoran. Notes on Cardiorespiratory Diseases of the Dog and Cat
2. K. V.F. Jubb, Peter C. Kennedy, Nigel Palmer. Pathology of Domestic Animals, Volume 3 (4th Edition)
3. Famula TR, Siemens LM, Davidson AP, Packard M. Evaluation of the genetic basis of tricuspid valve dysplasia in Labrador Retrievers
4. Schweiz Arch Tierheilkd. Tricuspid valve dysplasia in fifteen dogs