Aorto-left atrial fistula secondary to aortic infective endocarditis in a dog with a bicuspid aortic valve.

An 11-year-old male neutered American bulldog was presented for evaluation of thrombocytopenia, acute onset of ataxia, and vomiting. A new murmur was auscultated on physical examination. Transthoracic echocardiographic examination revealed a bicuspid aortic valve, vegetative lesions on the aortic valve, and continuous shunting from the aortic root to the left atrium through an aorta to left atrial fistula. The dog was euthanized due to its guarded prognosis and critical condition. Pathological examination confirmed presence of a bicuspid aortic valve, aorto-left atrial fistula, and aortic infective endocarditis. Antemortem blood culture revealed two unusual organisms: Achromobacter xylosoxidans and Fusobacterium mortiferum.

Infective endocarditis due to Erysipelothrix rhusiopathiae in a dog - a case report.

BACKGROUND: Infective endocarditis is a rare but severe condition associated with a high mortality rate in small animal patients. This condition is caused by a microbial (most often bacterial) infection of the valvular portion of the endocardium, from which proliferative and/or erosive lesions on the cardiac valves or immediately adjacent structures develop. The two most commonly affected cardiac valves are the aortic and mitral valves. CASE PRESENTATION: We report the clinical case of a 4-year old male neutered Bull terrier, 27.6 kg, body condition score 4/9, that presented with a 3-months history of pyrexia and general weakness. The patient history also revealed a transient left hind limb lameness (grade 2/4), which coincided with the onset of clinical signs about 3 months before presentation. On physical examination, a left-sided systolic heart murmur (grade 3/6) with the same intensity at the left heart base and apex, and an irregularly irregular heart rhythm were noted. Electrocardiography showed ventricular premature complexes, and echocardiography revealed lesions consistent with endocarditis involving the aortic and mitral valve. Bacterial culture of blood yielded a positive result, and the organism isolated was identified as Erysipelothrix rhusiopathiae. The extended patient history revealed that the dog lived close to a farm housing pigs and other livestock. CONCLUSION: We report a rare case of the premortal diagnosis of infective bacterial endocarditis in a dog due to E. rhusiopathiae infection. Most reports about this condition are from necropsy series. This clinical case report emphasizes that E. rhusiopathiae infection and bacteremia should be considered as a differential diagnosis in dogs with suspected infective endocarditis, especially in dogs living in rural areas with access to livestock and particularly farm pigs. Also, particular emphasis should be placed on the zoonotic potential of this infectious disease.