A Bearded Collie was presented with clinical signs of intermittent weakness, intermittent pain in the back legs and a bilateral absence of the femoral pulse. Further diagnostic investigations revealed proteinuria, hypoproteinaemia, hyperlipidaemia and azotaemia. A quantitative estimation of the proteinuria using a protein/creatinine ratio indicated a loss of 483 mg kg-1 of protein per day. A large caudal aortic thrombosis was demonstrated by means of non-selective angiography and ultrasonographic examination. Autopsy confirmed an extensive aortic thrombus extending from the level of the fourth lumbar vertebra to include both iliac and femoral arteries at the level of the stifle joints. A large thrombus, 4 cm in length, was also found in the pulmonary artery. Histopathological examination of the kidneys revealed a subacute to chronic membranoproliferative glomerulonephritis.