The results obtained in this investigaton indicated that estima tion of total serum cholesterol, blood urea and non-protein nitrogen as well as evaluation of the alterations in haematological constituents could be used successfully in prognostication of hepattc surgery. This was well exampiified in 5 dogs by the restoring of haematological constituents and serum cholesterol to their normal values within 20 days after cholecystectomy, and the elevation of blood urea and non-protein nitrogen levels 45 days post operation.