The effect of D-galactosamine (GalN) on the blood clearance of 99mTc-phytate (99mTc-P) in dogs was examined, and the blood clearance test of 99mTc-P was compared with the cases of the serum transaminase and bilirubin test. Serum transaminase and bilirubin levels in dogs increased dose-dependently after GalN administration, and the degree of increase in these parameters was much higher than the cases in rats. The disappearance rate of 99mTc-P from blood in dogs decreased with the increase in dose of GalN and with the passage of time after the GalN administration. Changes of the blood clearance of 99mTc-P after GalN treatment in dogs may be influenced by the disorder in the hepatocytes. The blood clearance test of 99mTc-P in dogs showed a sensitive reaction for the acute hepatic dysfunction induced by GalN equally to the serum transaminase and bilirubin test.