HISTORY

A 18 kg 5-month-old female Rottweiler puppy was referred with a 5-week history of hemorrhagic diarrhoea, progressive lethargy, anorexia, weight loss and a sudden onset of a heart murmur. Physical examination showed depression, dehydration and pyrexia (39,8°C). The mucous membranes were pale and dry. The abdominal palpation was moderately painful. Other physical abnormalities included tachycardia (160 beats/min) and a left apical grade IV/VI systolic heart murmur. Biochemical abnormalities included elevated levels of serum alkaline phosphatase, hypoproteinemia and hypoalbuminemia. The cell blood count showed severe neutrophilic leukocytosis, monocytosis and a normocytic normochromic anemia. Urinalysis confirmed microscopical hematuria and leukocyturia. Echo-Doppler revealed a large cauliflower like mass (15 mm) on the septal leaflet of the mitral valve, with severe mitral regurgitation. Holter monitoring showed rare premature, monomorphic and isolated left ventricular complexes. Severe structural alterations of left kidney with signs of retroperitonitis were observed on abdominal ultrasonography. Histology of echo-guided percutaneous renal biopsy showed a severe necrotic and suppurated pyelonephritis. Blood culture confirmed bacteremia (Enterococcus faecalis). The same organism was isolated from urine bacterial culture (104/mL). Size of mitral valves, were doubled despite of medical treatment and five days later, dog developed a septic shock. Owners decided the euthanasia. Autopsy confirmed all the lesions.

DISCUSSION

The most common bacteria isolated in dogs with vegetative endocarditis are Staphylococcus aureus, E. Coli, b-hemolytic streptococci, Corynebacterium, Pseudomonas aeruginosa, and Erysipelothrix rhusiopathiae. In our knowledge, Enterococcus faecalis has never been reported with spontaneous vegetative endocarditis in small animal medicine. As in this case, definitive diagnosis of bacterial endocarditis is based on positive blood culture associated with varying clinical signs, laboratory abnormalities and ultrasound visualization of vegetative cardiac lesions. In our case, hemorrhagic gastro-enteritis and presence of Enterococcus faecalis in blood culture allow to establish the intestinal origin of bacteremia. Suppurated pyelonephritis was probably due to septic emboli. The kidneys (as here) and the spleen are the most common organs of secondary infection. Human echocardiographic studies suggest that patients with large vegetations (diameter more than 10 mm, as found as in the mitral valve of our dog) are at higher risk for these infective embolic complications. Human echocardiographic studies also suggest that persistence or increase of vegetation size during the treatment (as seen here) worsens prognosis.

This case illustrates that echocardiography associated with abdominal ultrasound has become an essential tool for the diagnosis of bacterial endocarditis and for the detection of septic embolisations, while waiting for blood culture results.