Influence of route of administration on the plasma concentrations of ivermectin in reindeer

The concentration of ivermectin in the plasma of reindeer was measured after it was administered either topically as a pour-on preparation at 500 μg kg⁻¹ bodyweight at different seasons to animals of different ages, or after subcutaneous and oral doses of 200 μg kg⁻¹ bodyweight. The plasma concentrations of ivermectin were highest and least variable after it was administered subcutaneously.