Endocarditis and Meningitis Caused by Streptococcus suis after Cardiac Surgery in a Sheep

A female Dorset-cross sheep developed labored respirations and was anorexic, weak, ataxic and febrile (42.0°C) 15 days after implantation of a cardiac device. Clinical pathologic evaluation identified a mild leukocytosis (11,800 cells/μ1), neutrophilia (8,969 cells/μ1), and hypokalemia (2.9 mmol/L). Despite intensive therapy, the animal was euthanized 7 days later. Necropsy of the sheep revealed meningitis and vegetative endocarditis associated with the cardiac device. Blood cultures collected antemortem and tissue cultures collected at necropsy yielded Steptococcus suis. Histopathology confirmed the diagnosis of bacterial valvular endocarditis and meningoencephalitis. A variety of environmental and host factors are proposed as contributing to the infection, and the zoonotic potential of S. suis is discussed.