Abstract
A 10-year-old male mixed breed dog was brought to the Veterinary Medical Center at Obihiro University because of continuing fever and depression for three weeks. A heart murmur and echocardiographic findings that revealed vegetation in the mitral valves were observed in the dog. Although antibiotics and other drugs were administered, the clinical symptoms of heart failure worsened on Day 7, and the dog died of pulmonary edema on Day 10. At the necropsy, a gross examination revealed mild cardiac dilatation and multifocal vegetations in the mitral valves. Staphylococcus haemolyticus had been detected by blood culture, while DNA fragments with 100 % similarity to Streptococcus canis were detected by PCR and sequence analysis using the vegetation. It was thought that the result of the blood culture was more likely to be contamination, and molecular techniques revealed that the infective endocarditis in the case was caused by Streptococcus canis. It was necessary to consider that the bacterium which causes infective endocarditis might be different from that cultured from blood.
