The Prevalence of Spontaneously Occuring Cardiovascular Disease in Dogs

Abstract

Three thousand dogs have been screened by clinical methods for the presence of cardiovascular disease. In 290 animals reliable signs of heart disease were found through clinical and post-mortem studies. Three hundred and twenty-two additional dogs presented signs suggesting heart disease, but the diagnosis could not be confirmed on further examination or the animals were not seen again. The clinical screening methods consisted of palpation of the cardiac region, auscultation of the heart, palpation of the femoral arteries and the recording of a single lead, precordial ecg. Confirming studies included 10 lead ecg''s phonocardiograms, blood pressure determinations, thoracic roentgenograms, angiocardiograms, and clinical laboratory studies. The most common types of cardiovascular disease found were: (1) chronic valvular fibrosis; (2) myocardial disease (necrosis, degeneration, myocarditis), sclerosis of the deep coronary arteries, and right ventricular dilatation and hypertrophy associated with Dirofilaria immitis infestation; and (3) congenital heart diseases. Of the 15 cases of congenital heart disease the 3 most common lesions were pulmonic stenosis (6), patent ductus arteriosus (4), and aortic stenosis (3). Of 275 cases of acquired heart disease there were 143 with chronic valvular disease there were 143 with chronic valvular disease, 35 with myocardial disease, 67 with both these lesions and 30 with other miscellaneous lesions. The prevalence rate of heart disease in different age groups increased from 47/1000 in the 1-4 age group to 367.3/1000 in the 13 and older group. Ninety-five of the 3000 dogs showed a total of 124 abnormal cardiac arrhythmias and conduction disturbances including the common forms of atrial and ventricular premature beats, A-V conduction disturbances, bundle branch block and W-P-W syndrome.