Bacterial endocarditis is an inflammation of the endocardium, where a bacterial colonization produces vegetation in the cardiac valve, which can alter its normal function causing regurgitations and hemodynamic alterations. Also, this infection can cause septic thromboembolism or inflammatory alterations like immune complexes. The present study describes the case of a female canine of 2.5 years of age that presented fever, depression, anorexia and a severe murmur (IV/VI) on the left side of the thorax. Laboratory exams revealed leukocytosis with left shift and renal failure. Besides, the echocardiography showed vegetation at the aortic valve that altered the hemodynamics producing a diastolic regurgitation jet. It was concluded that the lesion was compatible with bacterial endocarditis.