“Familial subvalvular aortic stenois in golden retrievers: inheritance and echocardiographic findings”

Subvalvular aortic stenosis (SAS) is a very common congenital heart disease in canines, particularly in Newfoundlands, Rottweilers, and Golden Retrievers. This study investigated whether subvalvular aortic stenosis is familial in Golden Retrievers. The researchers studied 73 Golden Retrievers, determined whether each dog had SAS based off echocardiographic measurements, and analyzed three-generation pedigrees of the dogs.

Diagnoses of SAS was determined by subcostal continuous-wave Doppler measurements aortic velocities. An aortic velocity greater than 2.5 m/s, along with a presence of a left basilar systolic ejection murmur, was found in 32 golden retrievers, who were classified as having SAS. An aortic velocity less than 1.8m/s caused the dogs to be considered to be unaffected by SAS and occurred in 27 of the Golden Retrievers. The remaining 14 dogs with aortic velocities between 1.8m/s and 2.5m/s fell into the category of equivocal. 

The affected dogs were then further studied to identify whether SAS in golden retrievers is phenotypically similar to SAS in other breeds. Data of whether the SAS-diagnosed dogs had three echocardiographic characteristics of SAS was collected. These three characteristics are aortic insufficiency (AI), left ventricular hypertrophy (LVH), and a visible subvalvular ridge. Of the 32 SAS-affected Golden Retrievers, 20 had AI, 12 had LVH, and 20 had a subvavular ridge. A disease status score per dog was then calculated by adding the number of echocardiographic characteristics and, thus, ranged from 0 to 3. The median of the disease status score was 2. Statistical analysis revealed a correlation between aortic velocity and disease status score, supporting the idea that the more severe the disease, the greater frequency these characteristics occur. The results of the ranges of aortic velocities and the echocardiographic characteristics in SAS-affected Golden Retrievers indicate that SAS in Golden Retrievers is phenotypically similar to SAS in other breeds. The disease status score being affected by the age of the dogs was ruled out as the disease status score did not correlate to age.

Three generation pedigrees for 66 of the 73 golden retrievers were then studied. It was concluded that SAS is, in fact, familial for golden retrievers. In the pedigree analysis, the researchers also evaluated that the genes responsible for SAS could not be autosomal dominant, X-linked dominant, or X-linked recessive. However, they were unable to definitively determine what the mode of inheritance is.

 

Stern, J., Meurs, K., Nelson, O., Lahmers, S. and Lehmkuhl, L., 2012, Familial subvalvular aortic stenosis in golden retrievers: inheritance and echocardiographic findings. Journal of Small Animal Practice, 53: 213–216.

http://onlinelibrary.wiley.com/doi/10.1111/j.1748-5827.2011.01187.x/full