RESUMEN
INTRODUCTION: Sepsis is a serious problem in felines with a mortality rate ranging from 29-79%. Neisseria spp. is considered a commensal microorganism of the oral cavity of dogs and cats and is usually isolated from human wounds resulting from bites of these animals. CASE REPORT: The present report describes clinical, imaging and laboratory findings of a feline with sepsis wherein commensal and multidrug-resistant (MDR) Neisseria spp. was isolated. The feline presented a history of four days of anorexia, dyspnea, prostration, and, pericardial, pleural and abdominal effusions. Pericardiocentesis was performed and hemorrhagic exudate was observed. The animal died after 11 days of treatment with gentamicin and amoxicillin combined with clavulanic acid. During necropsy, the abdominal cavity was found to be filled with greenish-yellow content and the pericardial sac was thickened with a large amount of purulent secretion. Histopathology revealed sepsis with necrotizing suppurative pericarditis, diffuse mononuclear pneumonia and necrotic pleuritis, leading to secondary bacterial infection. CONCLUSIONS: Commensal Neisseria spp. are important zoonotic bacteria, which trigger a serious disease in felines. However, it has not been reported to cause sepsis with pneumonia, suppurative necrotizing pericarditis and pericardial effusion.