RESISTANCE OF GASTROINTESTINAL STRONGYLATES IN SHEEP TO IVERMECTIN

Abstract

The research was conducted to determine the effectiveness of a suspension, which was prepared in the laboratory of veterinary medicine of the All-Russian Research Institute of Sheep and Goat Breeding, branch of the FSBSI “North Caucasus Federal
Agricultural Research Center”. It contained 2.5% of Praziquantel and 0.5% of Ivermectin
against the gastrointestinal strongylates in sheep.
The studies were carried out in 2021 in sheep breeding farms of the Stavropol Territory: APC collective farm “Rossiya” in the Apanasenkovsky District and APC breeding
farm “Vostok” in the Stepnovsky District. The drug was given once, individually. Infection
of animals with gastrointestinal strongylates was determined by the results of scatoscopy
before and 14-15 days after the administration of the drug, by flotation technique, using an
aqueous solution of ammonium nitrate. It was found that the effectiveness of a suspension
control sample, which contained 2.5% of Praziquantel and 0.5% of Ivermectin was not the
same in sheep farms of the Stavropol Territory. Thus, in the APC collective farm “Rossiya”
in the Apanasenkovsky District, a suspension in doses of 0.4, 0.6, 0.8, 1.0 ml/10 kg of animal weight showed low efficiency – 12.1, 41.0, 60.4, 67. 0%, and no animal was completely
free from parasites. Absolutely different situation was in the APC breeding farm “Vostok”
in the Stepnovsky District. The use of the suspension already at a dose of 0.4 ml/10 kg of
animal weight provided 70% of animals completely free of parasites and 65.2% of helminths in relation to their number in the initial state before the use of the anthelmintic. The
next dose of 0.6 ml/10 kg of animal weight provided already high number of animals completely free of parasites (90%) and 81.6% of helminths in relation to their number in the initial state before the use of the anthelmintic. The next doses of 0.8 and 1.0 ml/10 kg of animal weight completely freed the animals from the gastrointestinal strongylates. From the
obtained data, it can be concluded that Ivermectin, which has been used for several decades
in various dosage forms in the Stavropol Territory, provides different effectiveness, which,
in our opinion, indicates the occurrence of resistance of gastrointestinal strongylates to
Ivermectin.