Susceptibility of helminth species from horses against different chemical compounds in Brazil.
Abstract: By means of parasitological necropsies, the present study aimed to evaluate, in six experiments, the degree of susceptibility or resistance of different helminth species which naturally infect horses to ivermectin 0.2 mg/kg, abamectin 0.2 mg/kg, moxidectin 0.4 mg/kg, trichlorfon 35 mg/kg, ivermectin 0.2 mg/kg+praziquantel 2.5 mg/kg, abamectin 0.2 mg/kg+praziquantel 2.5 mg/kg and ivermectin 0.2 mg/kg+6.6 mg/kg pyrantel. At experimental day zero, the horses were allocated to treatment groups based on average counts of strongylid eggs per gram of feces (EPG) obtained on days -3, -2 and -1. Oxyuris sp. infections were confirmed as positive or negative. All the animals in the six experiments were naturally infected by this helminth species. Each group (control or treated) consisted of six animals. All the assessed Habronema muscae populations analyzed were susceptible to ivermectin, abamectin and moxidectin. Of the six Trichostrongylus axei populations, four were susceptible to ivermectin, abamectin, moxidectin, trichlorfon and ivermectin+praziquantel, and two were resistant to abamectin+praziquantel and ivermectin+pyrantel. Both Strongyloides westeri populations analyzed were susceptible to ivermectin, abamectin, moxidectin and abamectin+praziquantel. For O. equi, resistance was found in four different populations treated with ivermectin, abamectin, moxidectin, trichlorfon and ivermectin+praziquantel. Only combinations of abamectin+praziquantel and ivermectin+pyrantel were effective against this parasite species. All the large strongyles diagnosed in the present study (Strongyus edentatus, Strongyus vulgaris and Triodontophorus serratus) were susceptible to all the chemicals tested, with the exception of trichlorfon. Of the Cyathostominae populations, one was diagnosed as resistant to ivermectin and another to trichlorfon. The remaining populations from this nematode group were considered to be sensitive to ivermectin, abamectin, moxidectin, ivermectin+praziquantel, abamectin+praziquantel and ivermectin+pyrantel. New studies should be performed in different regions to evaluate the efficacy of trichlorfon in others field populations of helminthes.
Copyright © 2015 Elsevier B.V. All rights reserved.
Publication Date: 2015-08-06 PubMed ID: 26277565DOI: 10.1016/j.vetpar.2015.07.041Google Scholar: Lookup
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- Journal Article
Summary
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This study investigates the effectiveness of various chemical compounds in combating specific types of parasitic worms in horses in Brazil and identifies which worms are susceptible or resistant to these treatments.
Research Methodology
- The research was conducted by conducting parasitological necropsies in six experiments.
- Horses naturally infected by various helminth species were allocated into treatment groups based on the average counts of strongylid eggs per gram of feces (EPG) three days prior to the start of the experiment.
- The presence of Oxyuris sp. infections was determined and all animals included were naturally infected by this parasite.
- Each trial group, whether treated or control, consisted of six horses.
Treatments Assessed
- The anti-parasitic compounds tested included ivermectin, abamectin, moxidectin, trichlorfon, ivermectin+praziquantel, abamectin+praziquantel, and ivermectin+pyrantel.
- The authors evaluated the effectiveness of these treatments against various helminth populations, focusing on Habronema muscae, Trichostrongylus axei, Strongyloides westeri, O. equi, Cyathostominae and large strongyles such as Strongyus edentatus, Strongyus vulgaris and Triodontophorus serratus.
Findings
- All assessed Habronema muscae populations were susceptible to ivermectin, abamectin and moxidectin.
- Out of six Trichostrongylus axei populations, four were susceptible to the tested compounds while two were resistant to abamectin+praziquantel and ivermectin+pyrantel.
- Both Strongyloides westeri populations analyzed were susceptible to ivermectin, abamectin, moxidectin and abamectin+praziquantel.
- Four different O. equi populations demonstrated resistance to all tested compounds except abamectin+praziquantel and ivermectin+pyrantel.
- All large strongyles were susceptible to all the tested chemicals barring trichlorfon.
- Of the Cyathostominae populations, one was found resistant to ivermectin, and another one was resistant to trichlorfon. The remaining populations were sensitive to most tested treatments.
Conclusion and Future Research
- The study provides valuable information regarding the susceptibility and resistance of various helminth species to specific anti-parasitic compounds commonly used in horse treatment.
- The authors recommend that further research should be conducted in different regions to evaluate the effectiveness of trichlorfon and potentially identify other field populations of helminths that may have developed resistance.
Cite This Article
APA
Felippelli G, Cruz BC, Gomes LV, Lopes WD, Teixeira WF, Maciel WG, Buzzulini C, Bichuette MA, Campos GP, Soares VE, Bergamasco PL, de Oliveira GP, da Costa AJ.
(2015).
Susceptibility of helminth species from horses against different chemical compounds in Brazil.
Vet Parasitol, 212(3-4), 232-238.
https://doi.org/10.1016/j.vetpar.2015.07.041 Publication
Researcher Affiliations
- CPPAR - Animal Health Research Center, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, Via de acesso Prof. Paulo Donatto Castellane, s/n°. CEP: 14884-900, Jaboticabal, São Paulo, Brazil.
- CPPAR - Animal Health Research Center, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, Via de acesso Prof. Paulo Donatto Castellane, s/n°. CEP: 14884-900, Jaboticabal, São Paulo, Brazil.
- CPPAR - Animal Health Research Center, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, Via de acesso Prof. Paulo Donatto Castellane, s/n°. CEP: 14884-900, Jaboticabal, São Paulo, Brazil.
- CPPAR - Animal Health Research Center, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, Via de acesso Prof. Paulo Donatto Castellane, s/n°. CEP: 14884-900, Jaboticabal, São Paulo, Brazil; Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO 74605-050, Brazil.. Electronic address: wdzlopes@hotmail.com.
- CPPAR - Animal Health Research Center, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, Via de acesso Prof. Paulo Donatto Castellane, s/n°. CEP: 14884-900, Jaboticabal, São Paulo, Brazil.
- CPPAR - Animal Health Research Center, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, Via de acesso Prof. Paulo Donatto Castellane, s/n°. CEP: 14884-900, Jaboticabal, São Paulo, Brazil.
- CPPAR - Animal Health Research Center, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, Via de acesso Prof. Paulo Donatto Castellane, s/n°. CEP: 14884-900, Jaboticabal, São Paulo, Brazil.
- CPPAR - Animal Health Research Center, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, Via de acesso Prof. Paulo Donatto Castellane, s/n°. CEP: 14884-900, Jaboticabal, São Paulo, Brazil.
- CPPAR - Animal Health Research Center, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, Via de acesso Prof. Paulo Donatto Castellane, s/n°. CEP: 14884-900, Jaboticabal, São Paulo, Brazil.
- CPPAR - Animal Health Research Center, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, Via de acesso Prof. Paulo Donatto Castellane, s/n°. CEP: 14884-900, Jaboticabal, São Paulo, Brazil.
- CPPAR - Animal Health Research Center, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, Via de acesso Prof. Paulo Donatto Castellane, s/n°. CEP: 14884-900, Jaboticabal, São Paulo, Brazil.
- CPPAR - Animal Health Research Center, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, Via de acesso Prof. Paulo Donatto Castellane, s/n°. CEP: 14884-900, Jaboticabal, São Paulo, Brazil.
- CPPAR - Animal Health Research Center, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, Via de acesso Prof. Paulo Donatto Castellane, s/n°. CEP: 14884-900, Jaboticabal, São Paulo, Brazil.
MeSH Terms
- Animals
- Anthelmintics / pharmacology
- Brazil / epidemiology
- Drug Resistance
- Helminthiasis, Animal / epidemiology
- Helminthiasis, Animal / parasitology
- Helminths / drug effects
- Horse Diseases / parasitology
- Horses
Citations
This article has been cited 7 times.- Nielsen MK. Apparent treatment failure of praziquantel and pyrantel pamoate against anoplocephalid tapeworms. Int J Parasitol Drugs Drug Resist 2023 Aug;22:96-101.
- Tombak KJ, Hansen CB, Kinsella JM, Pansu J, Pringle RM, Rubenstein DI. The gastrointestinal nematodes of plains and Grevy's zebras: Phylogenetic relationships and host specificity. Int J Parasitol Parasites Wildl 2021 Dec;16:228-235.
- Barlaam A, Traversa D, Papini R, Giangaspero A. Habronematidosis in Equids: Current Status, Advances, Future Challenges. Front Vet Sci 2020;7:358.
- Ullah A, Geng M, Chen W, Zhu Q, Shi L, Zhang X, Akhtar MF, Wang C, Khan MZ. Effect of Parasitic Infections on Hematological Profile, Reproductive and Productive Performance in Equines. Animals (Basel) 2025 Nov 14;15(22).
- Rodriguez Velazquez D, Forte L, Varela Guerrero JA, Díaz Alvarado T, Elghandour MMMY, Maggiolino A, De Palo P, Salem AZM. Could Mesquite (Prosopis juliflora) Help Control Gastrointestinal Parasites in Horses?. Animals (Basel) 2025 Apr 28;15(9).
- Américo L, Aquino LPCT, Moura AB, Ribeiro GSN, Fonteque JH, Chryssafidis AL. Cutaneous and conjunctival habronemosis in horses treated at the Veterinary Hospital of the Santa Catarina State University, Brazil. Rev Bras Parasitol Vet 2024;33(3):e004224.
- Nielsen MK. Anthelmintic resistance in equine nematodes: Current status and emerging trends. Int J Parasitol Drugs Drug Resist 2022 Dec;20:76-88.
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