For deworming undomesticated herd horses as well as wild animals in reserves (bison, red deer, wild boars, etc.), an antiparasitic supramolecular complex preparation based on ivermectin and polymers (arabinogalactan and HDPE) was developed in the ratios of wt.%: 2:49:49; it is a light cream powder with particle size 1.0-10 microns, which was obtained using the method of mechanochemistry. When evaluating the parameters of acute and acute cutaneous toxicity, the supramolecular complex of ivermectin administered through the enteric route to white mice and applied to the skin according to GOST 12.1.007-76 belongs to class IV of low toxic substances, and according to the accepted classification (L.I. Medved, 1964), class of substances with subtle accumulation. The supramolecular complex of ivermectin does not have immunotoxic activity. The drug is administered in a mixture with food individually in a prescribed therapeutic dose of 0.15 mg / kg, as well as by the method of group feeding in a mixture with feed compound in a dose of 0.2 mg / kg. Deworming of herd horses with a preparation to be used in a mixture with food is technically convenient and practically not difficult, while excluding physical stress during fixation of animals, and industrial injuries. No side effect is observed after deworming.