Efficacy of a modified albendazole and ivermectin formulation on treatment and the seasonal dynamics of sheep helminthosis

The aim of this study was to develop a complex antiparasitic compound containing albendazole (ABZ) and ivermectin (IVM) based on solid dispersion to increase the bioavailability of the active substances, to evaluate the efficacy of the formulation, and to monitor the effect of its use on the seasonal dynamics of sheep helminthosis for one year. To obtain the complex, a mechanochemical technology with joint grinding of ABZ, IVM, and polymer (polyvinylpyrrolidone, PVP) was used. The formulation was then used to study its efficacy in sheep helminthosis using coprological methods. Additionally, the sheep were treated both in spring and autumn to study the seasonal dynamics of infection with nematodes, cestodes, and trematodes. The suspension, administered at a rate of 0.2 mg IVM and 3 mg ABZ/kg body weight, showed 100% efficacy against the entire complex of helminths in both spring and autumn treatments. Furthermore, sheep admitted to winter stall maintenance presented fairly low rates of extensiveness (10.0–13.7%) and intensity (9.5–14.7 EPG) of infection with all types of helminths. The present study showed that administrations of the newly formulated anthelminthic (CAPS-AI) twice in the year, i.e., in the spring (before going out to pasture) and in the fall (before placing them in stalls), ensured a relatively low level of sheep helminthoses, making it possible to prevent the clinical manifestation of helminthosis and subsequently economic losses.