1. Dogs with bile-duct ligation retain salt and water and form ascites. The present study was undertaken to examine the role of haemodynamic factors in the aetiology of this sodium retention.
2. Haemodynamic studies were performed in five dogs before and 5 weeks after bile-duct ligation.
3. After the operation there was an insignificant fall in mean arterial pressure, a significant rise in mean cardiac index and a significant fall in mean total peripheral resistance.
4. It is concluded that heart failure is not a factor in renal sodium retention of the dog with bile-duct ligation, since the central venous pressure was not elevated.
5. The haemodynamic pattern and the tendency to salt retention in the dog with chronic bile-duct ligation closely resemble findings reported in patients with cirrhosis of the liver, and it is suggested that oedema formation in patients with cirrhosis of the liver and dogs with chronic bile-duct ligation shares a common aetiology.