Subvalvular Aortic Stenosis (SAS)
Subvalvular Aortic Stenosis (SAS) is a defect which occurs under the juncture of the aorta and the main chamber of the heart. It is called that because there is a partial obstruction under this juncture (hence SUBaortic) of the flow of blood into the heart's chamber. Some symptoms of SAS include a heart murmur, exercise intolerance, fainting and/or coughing.
A doppler echocardiogram is the definitive tool in diagnosing SAS,which is a genetic condition. It can be diagnosed at 12 months.Heart murmurs are graded on a 0 to 6 scale: 0/6 means no murmur; 1/6 and 2/6 are considered "mild"; 3/6 and 4/6 are considered "moderate"; and 5/6 and 6/6 are considered "severe".
While a qualified veterinarian could hear a murmur, the definitive tool is the echocardiogram. As with boxer cardiomyopathy, there is debate about a dog who might not present with a murmur at 12 months but develop SAS at a later date. It is important, both as a breeder and a boxer puppy buyer, to do research about all health issues. Screening tests are not a guarantee but a smart breeder will be aware and have had their breeding stock tested to the best of their ability.
At this time, the Orthopedic Foundation of American (OFA) is the registry for not only cardio testing but for orthopedic results for hips and elbows. OFA has not yet given permission to link to their site, but good amount of information is available there.