Congenital Heart Disease in Dogs

 Jan Grebe

An excellent presentation was given by Samantha Kovacs on work she and Dr. Joshua Stern of the UC/Davis Vet School have done focused on updates on two of the most common congenital (present at birth) heart defects in dogs.  Subaortic stenosis and Pulmonic stenosis are the most common inherited heart diseases and occur most often in certain breeds : Golden Retriever, Newfoundland, Rottweiler, Bouvier des Flandres, Bullmastiff, Bulldog, and French Bulldog. Of those, Bullmastiffs and Newfoundlands had the highest incidence of Subaortic stenosis, while Pulmonic stenosis was most commonly found in Bulldogs and French Bulldogs.

Pulmonic Stenosis (PS) is a heart disease, often inherited, caused by one or more abnormalities of the pulmonic valve that controls the ejection of blood from the right ventricle of the heart into the pulmonary artery leading to the lungs.  Research has identified genetic markers of Pulmonic stenosis in Bulldogs, and researchers are working to identify similar genetic markers in French Bulldogs.  In Bulldogs, studies have found that inherited pulmonic stenosis is caused by autosomal recessive genes.  This is identified when a given dog or bitch seems to produce puppies with this defect more than the average breedings do, and genetic studies have found common genetic markers associated with it.  

The identification of a mutation in Bulldogs will aid breeders in making responsible decisions to reduce the prevalence of this condition. The first step in this study will be clinical evaluation and genetic sample collection to be followed by a genome wide association study, which looks at genetic markers throughout the entire dog genome. The results from dogs that have the disease are then compared with healthy dogs. The investigators expect to identify a chromosomal region that is likely to contain a mutation for PS in this breed, which can then lead to a diagnostic test, the first step on the path to reducing the prevalence of this devastating disease in Bulldogs.

Dr. Stern and his group at UC/Davis Vet school want to conduct a similar study in Frenchies, and have asked that any breeders who seem to find certain breedings producing such Pulmonic stenosis more often than others contact them at sterngenetics@ucdavis.edu. Results of studies of this sort can identify mutations, and ultimately genetic markers that would help breeders inform future selection of breeding pairs and make responsible decisions to reduce the incidence of this congenital heart disease in our breed.