12, a Specific echocardiographic reference values have been established for several breeds, 13– 17 but evaluation of normal echocardiographic variation within a breed remains problematic, particularly for breeds such as the Boxer, which is characterized by large variation in body size. Previous studies have documented significant variability in echocardiographic measurements in dogs of different somatotypes 12 and have demonstrated the limitations of linear regression models in predicting echocardiographic measurements even among dogs of the same breed. 9– 11 Prior echocardiographic studies have focused on the LV outflow tract of the Boxer and have confirmed a smaller LV outflow tract area and aortic size contributing to the higher aortic velocities and murmurs noted in the breed. 1, 2 Echocardiography is the least invasive method of diagnosing aortic stenosis, but confirmation of mild or equivocal disease remains problematic because of the high incidence of cardiac murmurs and intrinsically higher aortic velocities documented in Boxers. Subaortic stenosis is also prevalent in the Boxer and is the most common congenital cardiac disease in the breed according to most reports. 4 Although some Boxers also develop overt myocardial failure and dilated cardiomyopathy, the relationship between ARVC and the presence or development of left ventricular (LV) dysfunction is unclear. In a prior study of 188 Boxers assessed by 24-hour ambulatory ECG (AECG), more than 30% of the dogs had more than 100 ventricular premature depolarizations in 24 hours, which has been proposed as a criterion for the diagnosis of ARVC. 1– 5 Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a common entity in the breed, 4, 6 characterized by serious ventricular arrhythmias, syncope, and high risk of sudden death.

Boxer dogs are routinely screened by echocardiography and ECG to exclude congenital and acquired heart disease.

Boxer dog big