Abstract: A male British Shorthair cat, which was presented with respiratory distress and mild paralysis of the hind limbs, was diagnosed using basic information and history investigation, physical examination, laboratory tests and imaging examination, and with reference to the modified Duke diagnostic criteria. The results showed that physical examination revealed no femoral artery pulsation in both hind limbs and pain on palpation; serum creatine kinase concentration was mildly elevated to 1 019 U/L（reference range 0-386 U/L）; chest X-ray showed pleural cavity effusion; echocardiography showed the presence of a hyperechoic redundancy on the aortic valve leaflets and aortic regurgitation; abdominal B-mode ultrasonography showed incomplete embolization of the abdominal aortic cavity. Based on these findings, the cat was diagnosed with infective endocarditis（IE）; after treatment with oxygen, diuretics, analgesia, antithrombotic and anti-infective measures, the cat’s condition improved significantly. Survival time reached five months, which was relatively long. The results suggested that echocardiography was important in confirming the diagnosis of infective endocarditis, while for the more common feline cardiomyopathies and congenital heart disease, feline infective endocarditis had different treatment options and a worse prognosis.