ABSTRACT
Infection of the cardiac valves and other endocardial tissue is relatively uncommon. Congestive heart failure (CHF) is a common sequela. Invasion and infection of the endocardial surface occurs from bacteria or other microbes present in blood flowing past it. Endocarditis usually involves the aortic, mitral, or both valves in dogs, cats, and horses. Recurrent bacteremia can result from infections of the skin, mouth, urinary tract, prostate gland, lungs, gut, or other organs, and also from prolonged IV catheter placement. Endothelial damage, with secondary platelet and fibrin aggregation, probably serves as a nidus for circulating bacterial colonization in most cases of endocarditis. The possible effect of immunosuppressive therapy in predisposing to infective endocarditis is unclear. Endothelial disruption stimulates platelet activation and a local coagulation response, with resulting aggregate of fibrin, platelets, red blood cells (RBCs) and leukocytes. Colonizing bacteria can secrete enzymes that damage valve tissue and promote vegetative lesion proliferation.
