Infective vegetative endomyocarditis of the posteromedial papillary muscle in a cat

Abstract An 8‐year‐old female neutered Burmese cat was referred for suspected congestive heart failure and thromboembolism of the right thoracic limb. Echocardiography revealed a large proliferative lesion in the left‐ventricular outflow tract attached to the posteromedial papillary muscle and oscillating across the aortic valve. Blood cultures documented growth of alpha‐haemolytic Streptococcus species. Antibiotic and supportive therapy were instigated; however, the cat was euthanased several days later for recurrent congestive heart failure signs that were refractory to treatment. Histopathology of the lesion revealed a fibrino‐haemorrhagic exudate with necrosis and embedded bacterial colonies, confirming a diagnosis of infective endomyocarditis.