Prevalence of congenital heart disease in Boxers in Italy

Abstract OBJECTIVE: To evaluate the prevalence of congenital heart disease in boxers in Italy by auscultation and echocardiography. METHODS: This randomized study involved 500 boxers. The inclusion criteria were that the animals should be asymptomatic, older than 1 year and with a pedigree. Dogs with a heart murmur underwent a complete echo-Doppler examination. The criteria for the diagnosis of aortic or pulmonic stenosis were: heart murmur on cardiac auscultation; direct imaging of the obstructive lesions; turbulent aortic or pulmonic flow with peak velocity of >2 m/sec and > 1.5 m/sec, respectively. RESULTS: 265 out of 500 dogs exhibited a heart murmur on cardiac auscultation. According to echo-Doppler examination, 89 (17.8%) dogs were affected with congenital heart disease. Subaortic stenosis and/or pulmonic stenosis accounted for all cases identified, although subaortic stenosis was more prevalent. Type I (63.75%) and Type II (21.25%) subaortic stenosis were the most common forms of the disease. Type A was the most prevalent type of pulmonic stenosis (74.2%). None of the dogs with a heart murmur of grade 1/6 or 2/6 complied with all the pre-selected criteria, and they were not considered to be affected with congenital heart disease. CONCLUSIONS: The prevalence of congenital heart disease in boxers in Italy appears to be very high (17.8%). In this study, subaortic stenosis and pulmonic stenosis accounted for all identified heart diseases. These findings support a the suspicion of these diseases when a heart murmur is found in a boxer, but only Doppler echocardiography can differentiate between subaortic stenosis and pulmonic stenosis.