A STANDARDIZED ORAL ZINC TOLERANCE-TEST FOR ASSESSMENT OF ZINC-ABSORPTION IN DOGS

Three oral zinc tolerance tests using increasing doses of elemental zi nc (0.5, 0.75 and 1.0 mg/kg) given as zinc sulphate (ZnSO4.7H2O) were carried out in eight normal beagles. The zinc tolerance curves obtaine d were similar to those described in man, with the peak plasma zinc co ncentration occurring 2 h after dosing. There was a considerable varia tion between individual animals in the peak plasma zinc concentration achieved with each dose. This would appear to limit the value of a zin c tolerance test in assessing the efficiency of zinc absorption in ind ividuals, although it may be of value in making comparisons between gr oups of dogs.