This study followed the uptake, distribution, and elimination of sodium arsenate administered in a single dose and in multiple doses, respectively, to Iranian dairy sheep and goats. In the single dosing study, the blood concentration data fit an open two-compartment model of the form:C b (t)=-(A+B)e (-kat) +Ae (-αt) +Be (-βt) Absorption distribution and elimination rate constants were statistically significantly different for the two animal species. In the multiple dosing study, arsenic accumulated in the blood of both animal species, as expressed by a one compartment model of the form:C t =C ss (1-e (-kt) ) Arsenic was eliminated rapidly at the termination of dosing, with the blood washout half-life being shorter in sheep than in goats. Urinary excretion was the major elimination route from the body of both species.