Relevance. Psoroptosis of sheep and goats is a chronic disease caused by the Psoroptes ovis, occurring in a subacute, acute, chronic, sometimes generalized form. It is characterized by a lesion in sheep and goats of thick-haired parts of the body, in goats — sometimes the auriclesIn view of the above, the determination of the most cost-effective modern broad-spectrum acaricidal and antiparasitic agents in the conditions of the Caspian region of the Russian Federation is an urgent task.Мethods. The prophylactic effect of the antiparasitic drugs Santomectin and Ivermek was studied on 90 animals, divided into 2 experimental groups and one control group. Animals of the first group were injected with the drug Ivermek (ivermectin — 10 mg and tocopherol acetate — vitamin E — 40 mg) once, at a dosage of 1 ml of the drug per 50 kg of body weight of the animal. The second group was administered Santomectin (1 ml of the preparation contains 5 mg of ivermectin and 125 mg of closantel). Santomectin was injected into the subscapular region intramuscularly, once, at a dose of 1 ml of the drug per 50 kg of animal body weight. The third control group was not treated with chemoprophylactic drugs. Animals were observed for 30 days.Results. The data obtained in the course of production experiments on the effect of the acaricidal activity of the preparations indicate that the use of the Santomectin preparation with a single injection with an active substance concentration of 0.1 mg ivermectin per 1 kg of live weight gives a preventive effect against Psoroptes ovis by 16.7% higher than the use of the drug “Ivermek” at a concentration of 200 µg of ivermectin per 1 kg of live weight.