Anthelmintic resistance of horse strongyle nematodes to ivermectin in São Paulo state, Brazil.

Autor: de Favare GM; Universidade Estadual Paulista (UNESP), School of Agrarian and Technological Sciences (FCAT), Dracena, SP 17900-000, Brazil. Electronic address: giordani.mascoli@unesp.br., de Almeida Cipriano I; Universidade Estadual Paulista (UNESP), School of Agrarian and Technological Sciences (FCAT), Dracena, SP 17900-000, Brazil., do Carmo TA; Universidade Estadual Paulista (UNESP), School of Agrarian and Technological Sciences (FCAT), Dracena, SP 17900-000, Brazil., Mena MO; Universidade Estadual Paulista (UNESP), School of Agrarian and Technological Sciences (FCAT), Dracena, SP 17900-000, Brazil., Guelpa GJ; Universidade Estadual Paulista (UNESP), School of Agrarian and Technological Sciences (FCAT), Dracena, SP 17900-000, Brazil., do Amarante AFT; Faculty of Veterinary Medicine and Animal Science - Unesp/FMVZ, Botucatu, SP, Brazil., de Soutello RVG; Universidade Estadual Paulista (UNESP), School of Agrarian and Technological Sciences (FCAT), Dracena, SP 17900-000, Brazil.
Jazyk: angličtina
Zdroj: Veterinary parasitology, regional studies and reports [Vet Parasitol Reg Stud Reports] 2023 Jun; Vol. 41, pp. 100864. Date of Electronic Publication: 2023 Mar 30.
DOI: 10.1016/j.vprsr.2023.100864
Abstrakt: The indiscriminate use of drugs to control gastrointestinal helminths in horses can lead to serious consequences for the animals, which represents a growing problem for health, animal welfare and productivity. Therefore, the present study aimed to evaluate the anthelmintic efficacy of ivermectin in naturally infected horses in the western region of the state of São Paulo. From May 2021 to April 2022, 123 naturally infected adult horses in 12 equine breeding farms (7 to 14 animals per farm) were evaluated with the fecal egg count reduction test. The horses had not been treated with anthelmintic drugs for at least 60 days before the start of the study. The animals were treated with ivermectin (0.2 mg/kg; Eqvalan®, Merial) administered orally according to recommended dosage by the manufacturer. Individual fecal samples were collected directly from the rectal ampulla and used to determine the eggs per gram of feces (EPG) and perform coproculture for identification of larvae on the day of anthelmintic treatment (D0) and 14 days later (D14). The fecal egg count reduction (FECR) on each property was calculated using the program Shiny-egg Counts R version 3.6.1, and the presence of anthelmintic resistance was confirmed when the FECR percentage was less than 95%, and when the lower confidence limit [LCI] was less than 90%. The pre-treatment average EPG count in the 12 properties was 991. In five properties the FECR was lower than 90%; in three properties between 90% and 95%; and in four properties equal to or greater than 95% after treatment with ivermectin. The occurrence of cyathostomins with resistance to ivermectin was recorded in the majority of the farms.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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