TY - JOUR
T1 - Egg reappearance periods of anthelmintics against equine cyathostomins
T2 - The state of play revisited
AU - Macdonald, Stephanie L.
AU - Abbas, Ghazanfar
AU - Ghafar, Abdul
AU - Gauci, Charles G.
AU - Bauquier, Jenni
AU - El-Hage, Charles
AU - Tennent-Brown, Brett
AU - Wilkes, Edwina J.A.
AU - Beasley, Anne
AU - Jacobson, Caroline
AU - Cudmore, Lucy
AU - Carrigan, Peter
AU - Hurley, John
AU - Beveridge, Ian
AU - Nielsen, Martin K.
AU - Jabbar, Abdul
AU - Hughes, Kristopher J.
N1 - Funding Information:
The authors are members of the Australian Equine Parasitology Advisory Panel supported by AgriFutures Australia and Boehringer Ingelheim Animal Health Australia. 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.
Publisher Copyright:
© 2022 The Authors
Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.
PY - 2023/4
Y1 - 2023/4
N2 - Cyathostomins are the most common and highly prevalent parasites of horses worldwide. Historically, the control of cyathostomins has mainly relied on the routine use of anthelmintic products. Increasing reports on anthelmintic resistance (AR) in cyathostomins are concerning. A potential method proposed for detecting emerging AR in cyathostomins has been estimating the egg reappearance period (ERP). This paper reviews the data available for the ERP of cyathostomins against the three major classes of anthelmintics, macrocyclic lactones, tetrahydropyrimidines, and benzimidazoles. Published peer-reviewed original research articles were obtained from three databases (PubMed, CAB Direct and Web of Science) and were evaluated for their inclusion in a systematic review. Subsets of articles were then subjected to a review of ERP data. A total of 54 (of 134) studies published between 1972 and 2022 met the criteria for inclusion in the systematic review. Until the beginning of 2022, there was no agreed definition of the ERP; eight definitions of ERP were identified in the literature, complicating the comparison between studies. Additionally, potential risk factors for the shortening of the ERP, including previous anthelmintic use and climate, were frequently not described. Reports of shortened ERP for moxidectin and ivermectin are frequent: 20 studies that used comparable ERP definitions reported shortened moxidectin and ivermectin ERPs of 35 and 28 days, respectively. It is unclear whether the ERPs of these anthelmintics reduced to such levels are due to the development of AR or some biological factors related to horses, cyathostomin species, and/or the environment. The ERPs for other anthelmintics, such as fenbendazole and pyrantel, were frequently not reported due to established resistance against these drugs. Future research in horses is required to understand the mechanism(s) behind the shortening of ERP for cyathostomins. Based on this systematic review, we propose recommendations for future ERP studies.
AB - Cyathostomins are the most common and highly prevalent parasites of horses worldwide. Historically, the control of cyathostomins has mainly relied on the routine use of anthelmintic products. Increasing reports on anthelmintic resistance (AR) in cyathostomins are concerning. A potential method proposed for detecting emerging AR in cyathostomins has been estimating the egg reappearance period (ERP). This paper reviews the data available for the ERP of cyathostomins against the three major classes of anthelmintics, macrocyclic lactones, tetrahydropyrimidines, and benzimidazoles. Published peer-reviewed original research articles were obtained from three databases (PubMed, CAB Direct and Web of Science) and were evaluated for their inclusion in a systematic review. Subsets of articles were then subjected to a review of ERP data. A total of 54 (of 134) studies published between 1972 and 2022 met the criteria for inclusion in the systematic review. Until the beginning of 2022, there was no agreed definition of the ERP; eight definitions of ERP were identified in the literature, complicating the comparison between studies. Additionally, potential risk factors for the shortening of the ERP, including previous anthelmintic use and climate, were frequently not described. Reports of shortened ERP for moxidectin and ivermectin are frequent: 20 studies that used comparable ERP definitions reported shortened moxidectin and ivermectin ERPs of 35 and 28 days, respectively. It is unclear whether the ERPs of these anthelmintics reduced to such levels are due to the development of AR or some biological factors related to horses, cyathostomin species, and/or the environment. The ERPs for other anthelmintics, such as fenbendazole and pyrantel, were frequently not reported due to established resistance against these drugs. Future research in horses is required to understand the mechanism(s) behind the shortening of ERP for cyathostomins. Based on this systematic review, we propose recommendations for future ERP studies.
KW - Anthelmintic resistance
KW - Anthelmintics
KW - Cyathostomins
KW - Egg reappearance period
KW - Horse
KW - Strongylid
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U2 - 10.1016/j.ijpddr.2022.12.002
DO - 10.1016/j.ijpddr.2022.12.002
M3 - Review article
C2 - 36543048
AN - SCOPUS:85144478697
SN - 2211-3207
VL - 21
SP - 28
EP - 39
JO - International Journal for Parasitology: Drugs and Drug Resistance
JF - International Journal for Parasitology: Drugs and Drug Resistance
ER -