Fibrinous pericarditis in the horse

During a period of 18 months, between July 1978 and January 1980, 4 adult horses were referred to the New York State College of Veterinary Medicine with evidence of congestive heart failure. Characteristic clinical abnormalities included marked muffling of heart sounds, tachycardia, jugular vein distention, and peripheral edema. Treatment with antibiotics, diuretics, and anti-inflammatory drugs was unsuccessful, and all four died or were euthanatized and necropsied. At necropsy, there was marked distention of the pericardial sac with fluid, and thick layers of fibrin were deposited uniformly over the epicardium. In 3 cases, attempts to isolate bacteria and viruses from pericardial fluid were unsuccessful; in the 4th case, Actinobacillus equuli was isolated on culture of the pericardial fluid.