Presumed renal arterial aneurysm in a cat.

A 3-year-old cat was presented for an abdominal ultrasound examination with apathy and anemia. The US revealed the enlargement of the left kidney with a hypoechoic subcapsular thickening. An abnormal, tortuous vessel was visible in the medulla with arterial flow on pulsed-wave Doppler examination. The CT examination confirmed the ultrasound findings and a presumptive diagnosis of the intraparenchymal renal aneurysm was made. Four days later, the cat presented again with a worsening of its condition. The US features were suggestive for that of an aneurysm rupture.