A screening program for subaortic and pulmonic stenosis in the Italian boxer dog population: prevalence and preliminary analysis

Subaortic (SAS) and pulmonic (PS) stenosis are congenital heart defects commonly affecting some dog breeds. The aim of this study was to assess the prevalence of SAS and PS in the Italian Boxer dog population, to investigate variation of the cardiac murmur grade and echocardiographic measures, and to perform a risk analysis of heart defects through logistic regression. Cardiovascular examination was carried out by 7 different veterinarians on 999 random dogs. Female dogs were 53.85% of the sample and the same proportion resulted in the sub-sample of affected dogs. The diagnosis was based on clinical and echocardiographic findings (peak velocity, flow type, obstruction severity). Based on value of the peak pressure gradient, SAS and PS were classified into 3 categories: mild, moderate and severe. For 68% of the dogs the cardiac murmur was absent or physiological, for 23% mild, and for 9% pathological. In agreement with other european studies, the prevalence of SAS was 7.8% whereas that of PS was 3.2%. The linear model used to analyse echocardiographic dimensional measures explained 20-38% of variation whereas the logistic regression analysis showed the role of the murmur grade as a risk factor for stenosis occurence.