AORTIC STENOSIS IN DOGS: CLINICAL CHARACTERISTICS AND SuRVIVAL IN 80 CASES

Eighty cases of dogs with aortic stenosis (AS) examined at the University Small Animal Clinic in Ljubljana, Slovenia between 2002 and 2007 were analysed. Our focus was on breed predisposition, natural course of the disease and survival of dogs with different grades of AS. German Boxer was the most common breed (56 dogs), followed by 8 Golden Retrievers, 3 Newfoundlands and 2 German Shepherds. Eleven breeds had only one representative. The genders were equally represented. Syncope occurred in 22% of dogs with mild AS, 20% of those with moderate AS and 37% of those with severe AS; in the last group, syncope occurred more frequently. Heart failure was a rare consequence of AS alone (4%) - most dogs with heart failure had a concurrent cardiac disorder. Fifty-one dogs had mild, 10 had moderate and 19 had severe AS. Most of the dogs had a subvalvular type of AS (94%). A positive correlation was found between murmur intensity and AS pressure gradient. A negative correlation was found between murmur intensity, left ventricular systolic diameter and survival days, and between AS pressure gradient and aortic root diameter. Pulmonic stenosis was the most common concurrent diagnosis (35% of dogs). Average survival for all dogs (n=55) was 2053±1198 days (range 312-4619 days) and no significant differences in survival were found between groups. 29% of dogs died by the end of the study, in the severe group mostly as a consequence of AS, and in the other groups because of concurrent cardiac or noncardiac diseases. 38% of dogs with severe AS lived as long as dogs from the other two groups. A good screening program is essential for lowering the incidence of aortic stenosis.