The use of a modified bromosulphthalein excretion test for the measurement of hepatic blood flow in calves.

Single intravenous injections of bromosulphthalein (BSP) were given to calves before and at intervals after the oral administration of 1000 metacercariae of Fasciola hepatica. The change in BSP concentration with time was analysed by computer to obtain the proportion of BSP extracted from plasma by hepatic cells (E) and the rate of hepatic blood flow (F). The increasing age of the normal calves during the 34 weeks of experiment had no significant effect on E or F. There was no significant effect of the duration of the fasciola lesion on E or F. When all tests on infected calves were compared as a group with tests on uninfected calves, there was a significant reduction in E(P less than 0.05) and in F(P less than 0.001) in the calves infected with F. hepatica. A survey of previously reported results suggests that sheep and cattle have a wide range of F values and that F is probably lower in 3-month-old calves than in adult cattle.