FREE SHIPPING over $40
OVER 9000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Home / Equine Research Bank / Acta Vet Scand / A field survey on anthelmintic resistance in equine small st...
Acta veterinaria Scandinavica1995; 36(1); 135-143; doi: 10.1186/BF03547710

A field survey on anthelmintic resistance in equine small strongyles in Norway.

Abstract: A field survey at 17 stables involving 221 horses was performed to evaluate the presence of anthelmintic resistance in the equine small strongyles (cyathostomes). The horses were allocated into treatment groups, and resistance to fenbendazole (FBZ), pyrantel pamoate (PYR) and ivermectin (IVM) was tested by the faecal egg count reduction test (FECR-test). Faecal samples were collected at the time of treatment, 14 days post treatment and 90 days post treatment. Resistance to FBZ, which was defined as a faecal egg count reduction < 95%, was found in 14 out of 17 stables. In 2 of the 14 stables the egg reductions were close to the limit of 95%, 91 and 93%, respectively. In 1 stable the egg reductions indicated resistance to PYR as well as detection of resistance to FBZ, 94% reduction for PYR and 85% for FBZ. No signs of resistance were detected to IVM. The investigation was performed in late autumn and winter, and due to the climatic conditions and cleaning procedures in the stables no reinfection took place during this period. The faecal egg count reduction from treatment till day 90 post treatment was used as an expression of the effect of PYR and IVM on the early stage (hypobiotic), late third stage and fourth stage larvae in the gut wall. This was justified because there was no reinfection and because the 14 day post treatment egg counts were zero or close to zero for the PYR and IVM treatment groups. The effects of PYR and IVM on the larval stages were compared and no statistically significant differences were found.
Get Full Text
Publication Date: 1995-01-01 PubMed ID: 7572451PubMed Central: PMC8095490DOI: 10.1186/BF03547710Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Clinical Trial
  • Journal Article
  • Randomized Controlled Trial
  • Research Support
  • Non-U.S. Gov't

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research article discusses a field survey conducted in Norway that investigated the presence of anthelmintic resistance in equine small strongyles (a type of horse parasite) against three specific drugs. The study found resistance to two of the drugs but none to the third.

Field Survey Details

  • The survey was administered in 17 stables with a total of 221 horses. The goal was to evaluate the level of resistance small strongyles — a common type of horse parasite — had developed against three anthelmintic drugs: fenbendazole (FBZ), pyrantel pamoate (PYR) and ivermectin (IVM).
  • Horses were assigned to treatment groups, and resistance to the drugs was tested through the faecal egg count reduction test (FECR-test), with samples collected at the time of treatment, 14 days post treatment and 90 days post treatment.

Anthelmintic Resistance Results

  • The study found resistance to fenbendazole (FBZ) in 14 out of the 17 stables; resistance was classified as an egg count reduction of less than 95%. However, in two of the 14 stables, egg reduction rates were close to the 95% threshold, measuring 91% and 93%.
  • In one of the stables, a resistance to both FBZ and pyrantel pamoate (PYR) was detected. The egg reduction was 94% for PYR and 85% for FBZ.
  • The research indicated no resistance to ivermectin (IVM).

Investigation Period and Conditions

  • The survey was carried out during late autumn and winter. Due to the climatic conditions and stable cleaning procedures, no reinfections occurred during the investigation period.
  • The faecal egg count reduction from treatment to 90 days post treatment was used as a measure of PYR and IVM effect on early-stage, late third-stage, and fourth-stage larvae in the gut wall. Since no reinfection occurred and because the 14-day post-treatment egg counts were zero or near zero for the PYR and IVM treatment groups, this measure accurately depicted drug efficacy.

Drug Effect Comparisons

  • The study compared the effects of PYR and IVM on the larvae at different stages. No significant statistical differences were found between the two drugs in terms of their abilities to treat the larvae.

Cite This Article

APA
Ihler CF. (1995). A field survey on anthelmintic resistance in equine small strongyles in Norway. Acta Vet Scand, 36(1), 135-143. https://doi.org/10.1186/BF03547710

Publication

Acta veterinaria Scandinavica
ISSN: 0044-605X
NlmUniqueID: 0370400
Country: England
Language: English
Volume: 36
Issue: 1
Pages: 135-143

Researcher Affiliations

Ihler, C F
  • Department of Large Animal Sciences, Norwegian College of Veterinary Medicine, Oslo.

MeSH Terms

  • Animals
  • Antinematodal Agents / therapeutic use
  • Drug Resistance
  • Fenbendazole / therapeutic use
  • Horse Diseases / drug therapy
  • Horse Diseases / parasitology
  • Horses
  • Ivermectin / therapeutic use
  • Norway
  • Parasite Egg Count / veterinary
  • Pyrantel / therapeutic use
  • Strongyle Infections, Equine / drug therapy
  • Strongylus / drug effects

References

This article includes 37 references
  1. Anderson N, Lord V. Anthelmintic efficacy of oxfendazole, fenbendazole and levamisole against naturally acquired infections of Ostertagia ostertagi and Trichostrongylus axei in cattle.. Aust. vet. J. 1979;55:158–162.
    doi: 10.1111/j.1751-0813.1979.tb15262.xpubmed: 464935google scholar: lookup
  2. Anon. Report of the working party for the animal health committee of the standing committee on agriculture: Anthelmintic resistance.. SCA Technical report series-no. 28, CSRIO Australia, East Melbourne 1989.
  3. Barger IA, Lisle IA. Benzimidazole resistance in small strongyles of horses.. Aust. vet. J. 1979;55:594–595.
    doi: 10.1111/j.1751-0813.1979.tb07056.xpubmed: 539943google scholar: lookup
  4. Bauer C, Merkt JC, Janke-Grimm G, Burger HJ. Prevalence and control of benzimidazole resistant small strongyles in German thoroughbred studs.. Vet. Parasit. 1986;21:189–203.
    doi: 10.1016/0304-4017(86)90065-8pubmed: 3529602google scholar: lookup
  5. Borgsteede FHM. The difference between two strains of Ostertagia ostertagi in resistance to morantel tartate.. Int. J. Parasit. 1988;18:499–502.
    pubmed: 3417377
  6. Bjorn H, Sommer C, Schougdrd H, Henriksen SA, Nansen P. Resistance to benzimidazole anthelmintics in small stongyles of horses in Denmark.. Acta vet. scand. 1991;32:253–260.
    doi: 10.1186/BF03546987pmc: PMC8127888pubmed: 1803938google scholar: lookup
  7. Dash KM, Hall E, Barger IA. The role of arithmetic mean worm egg counts in faecal egg count reduction tests and in monitoring strategic drenching programs in sheep.. Aust. vet. J. 1988;65:66–68.
    doi: 10.1111/j.1751-0813.1988.tb07359.xpubmed: 3355458google scholar: lookup
  8. Dorny P, Vercuysse J, Berghen P. Resistance of equine small strongyles to benzimidazoles in Belgium.. J. vet. Med. B. 1988;35:72–75.
    doi: 10.1111/j.1439-0450.1988.tb00469.xpubmed: 3376627google scholar: lookup
  9. Drudge JH, Elam G. Preliminary observations on the resistance of the horse strongyles to phenothiazine.. J. Parasit. 1961;47:38–39.
    doi: 10.2307/3274973pubmed: 0google scholar: lookup
  10. Drudge JH, Lyons ET. Newer developments in helminth control and Strongylus vulgaris research.. Proc. 155th Meeting Amer. Ass. Eq. Prac. 1965, 378–383.
  11. Drudge JH, Lyons ET. Benzimidazole resistance of equine strongyles. Critical test of six compounds.. Amer. J. vet. Res. 1979;40:590–594.
    pubmed: 517836
  12. Eysker M, Boersema JH, Kooyman FNJ. Effect of early season ivermectin and pyrantel treatments on strongylid infections in young Shetland ponies in the Netherlands.. Vet. Parasit. 1991;38:33–39.
    doi: 10.1016/0304-4017(91)90005-Gpubmed: 2024428google scholar: lookup
  13. Eysker M, Boersema JH, Kooyman FNJ. The effect of ivermectin against inhibited early third stage, late third stage and fourth stage larvae and adult stages of the cyathostomes in Shetlands ponies and spontaneous expulsion of these helminths.. Vet. Parasit. 1992;42:295–302.
    doi: 10.1016/0304-4017(92)90071-Gpubmed: 1496789google scholar: lookup
  14. Fisher MA, Jacobs DE, Grimshaw WTR, Gibbons LM. Prevalence of benzimidazole-resistance in equine cyathostome populations in south east England.. Vet. Rec. 1992;130:315–318.
    doi: 10.1136/vr.130.15.315pubmed: 1595158google scholar: lookup
  15. Gibson TE. The effect of repeated anthelmintic treatment with phenothiazine on the fecal egg counts of housed horses with some observations on the life cycle of Thrichonema spp. in the horse.. J. Helmint. 1953;27:29–40.
    doi: 10.1017/S0022149X00023488google scholar: lookup
  16. Gibson TE. Some experiences with small daily doses of phenothiazine as a mean of control of the strongylid worms in the horse.. Vet. Rec. 1960;72:37–41.
  17. Giordano DJ, Tritschler JP, Colers GS. Selection of ivermectin-resistant Trichostrongylus colubriformis in lambs.. Vet. Parasit. 1988;30:139–148.
    doi: 10.1016/0304-4017(88)90161-6pubmed: 3245107google scholar: lookup
  18. Helle O. Tiabendazol og fenbendazol til bekjempelse av parasitter hos unghest. (Treatment against parasites with thiabendazole and fenbendazole in young stallions. Development of resistance in small strongyles).. Norsk Vet.Tids. 1986;98:623–631.
  19. Ihler CF. Anthelmintika resistens hos gastrointestinal nematoder hos drpvtyggere, gris og hest. (Anthelmintic resistance in gastrointestinal nematodes of ruminants, pig and horses).. Norsk Vet. Tids. 1992;104:905–914.
  20. Johansen MV. An evaluation of techniques used for the detection of anthelmintic resistance in nematode parasites of domestic animals.. Vet. Res. Comm. 1989;13:455–466.
    doi: 10.1007/BF00402569pubmed: 2698534google scholar: lookup
  21. Kelly JD, Webster JH, Griffin DL, Whitlock HV, Martin ICA, Gunawan M. Resistance to benzimidazole anthelmintics in equine strongyles. 1. Frequency, geographical distribution and relationship between occurrence, animal husbandry procedures and anthelmintic usage.. Aust. vet. J. 1981;57:163–171.
    pubmed: 7271605
  22. Klei TR, Chapman MR, French DD, Taylor HW. Evaluation of ivermectin at an elevated dose against encysted equine cyathostome larvae.. Vet. Parasit. 1993;47:99–106.
    doi: 10.1016/0304-4017(93)90180-Upubmed: 8493773google scholar: lookup
  23. Lacey E. The role of the cytoskeletal protein, tubulin, in the mode of action and mechanism of drug resistance to benzimidazoles.. Int. J. Parasit. 1988;18:885–936.
    doi: 10.1016/0020-7519(88)90175-0pubmed: 3066771google scholar: lookup
  24. Lichtenfels JR. Parasites of domestic equids. Proc, helmint. Soc. Wash. 1975; p. 42.
  25. McKenna PB. The detection of anthelmintic resistance by the faecal egg reduction test: An examination of some of the factors affecting performance and interpretation.. N. Z. vet. J. 1990;38:142–147.
    doi: 10.1080/00480169.1990.35640pubmed: 16031600google scholar: lookup
  26. Nilsson O, Lindholm A, Christensson D. A field evaluation of anthelmintics in horses in Sweden.. Vet. Parasit. 1989;32:162–171.
    doi: 10.1016/0304-4017(89)90117-9pubmed: 2773268google scholar: lookup
  27. Pereira MC, Kohek I, Jr., Campos R, Lima SB, Foz RPP. A field evaluation of anthelmintics for control of cyathostomes of horses in Brazil.. Vet. Parasit. 1991;33:121–129.
    doi: 10.1016/0304-4017(91)90122-Cpubmed: 1858282google scholar: lookup
  28. Prichard RK, Hall CA, Kelly JD, Martin ICA, Donald AD. The problem of anthelmintic resistance in nematodes.. Aust. vet. J. 1980;56:239–251.
    doi: 10.1111/j.1751-0813.1980.tb15983.xpubmed: 7002142google scholar: lookup
  29. Roepstorff A, Bjorn H, Nansen P. Resistance of Oesophagostumum spp. in pigs to pyrantel citrate.. Vet. Parasit. 1987;24:229–139.
    doi: 10.1016/0304-4017(87)90044-6pubmed: 2956755google scholar: lookup
  30. Round MC, Simpson DJ, Haselden CS, Glendinning ESA, Baserville RE. Horse strongyle tolerance to anthelmintics.. Vet. Rec. 1974;95:517–518.
    doi: 10.1136/vr.95.22.517pubmed: 4462733google scholar: lookup
  31. Sangster NC, Kelly JD, Whitlock HW, Gunawan M, Porter CI. Trichostrongylus colubriformis and Ostertagia circumcincta resistant to levamisole, morantel tartrate and thiabendazole: Occurence of field strains.. Res. vet. Sci. 1979;27:106–110.
    doi: 10.1016/S0034-5288(18)32867-4pubmed: 504797google scholar: lookup
  32. Slocombe JOD, Cote JF. Small strongyles of horses with cross resistance to benzimidazole anthelmintics and susceptibility to unrelated compounds.. Can. vet. J. 1977;18:212–217.
    pmc: PMC1697636pubmed: 890649
  33. Taylor MA. Anthelmintic resistance in helminth parasites of domestic animals.. Agri. Zool. Rev. 1992;5:1–50.
  34. Uhlinger CA. Equine small strongyles: Epidemiology, pathology and control.. Comp. Cont. Ed. Pract. Vet. 1991;13:863–869.
  35. van Wyk J A, Malan FS. Resistance of field strains of Haemonchus contortus to ivermectin, closantel, rafoxanide and the benzimidazoles in South Africa.. Vet. Rec. 1988;123:226–228.
    doi: 10.1136/vr.123.9.226pubmed: 3176284google scholar: lookup
  36. Whitlock HV, Kelly JD, Porter CJ, Griffin DL, Martin ICA. In vitro field screening for anthelmintic resistance in strongyles of sheep and horses.. Vet.Parasit. 1980;7:215–232.
    doi: 10.1016/0304-4017(80)90026-6google scholar: lookup
  37. Xiao L, Herd RP, Majewski GA. Comparative efficacy of moxidectin and ivermectin against hypobiotic and encysted cyathostomes and other equine parasites.. Vet. Parasit. 1994;53:83–90.
    doi: 10.1016/0304-4017(94)90020-5pubmed: 8091622google scholar: lookup

Citations

This article has been cited 8 times.
  1. Jamshidpour R, Nabavi R, Moadab H, Rezaie F, Chale AC, Sargison N. Evaluation of Benzimidazole Resistance in Equine Cyathostomins in the Kermanshah Province of Iran Using Coprological Analysis and Allele-Specific PCR. Iran J Parasitol 2025 Jul-Sep;20(3):389-399.
    doi: 10.18502/ijpa.v20i3.19614pubmed: 41181201google scholar: lookup
  2. Cabaret J. Independent Development of Resistance to Main Classes of Anthelmintics by Gastrointestinal Nematodes of Ruminants and Horses. Pathogens 2025 Sep 5;14(9).
    doi: 10.3390/pathogens14090898pubmed: 41011797google scholar: lookup
  3. Dauparaitė E, Kupčinskas T, Varady M, Petkevičius S. Anthelmintic resistance of horse strongyle nematodes to fenbendazole in Lithuania. Acta Vet Scand 2022 Sep 15;64(1):26.
    doi: 10.1186/s13028-022-00645-ypubmed: 36109767google scholar: lookup
  4. Zanet S, Battisti E, Labate F, Oberto F, Ferroglio E. Reduced Efficacy of Fenbendazole and Pyrantel Pamoate Treatments against Intestinal Nematodes of Stud and Performance Horses. Vet Sci 2021 Mar 5;8(3).
    doi: 10.3390/vetsci8030042pubmed: 33807857google scholar: lookup
  5. Traversa D, von Samson-Himmelstjerna G, Demeler J, Milillo P, Schürmann S, Barnes H, Otranto D, Perrucci S, di Regalbono AF, Beraldo P, Boeckh A, Cobb R. Anthelmintic resistance in cyathostomin populations from horse yards in Italy, United Kingdom and Germany. Parasit Vectors 2009 Sep 25;2 Suppl 2(Suppl 2):S2.
    doi: 10.1186/1756-3305-2-S2-S2pubmed: 19778463google scholar: lookup
  6. Lind EO, Kuzmina T, Uggla A, Waller PJ, Höglund J. A field study on the effect of some anthelmintics on cyathostomins of horses in sweden. Vet Res Commun 2007 Jan;31(1):53-65.
    doi: 10.1007/s11259-006-3402-5pubmed: 17186406google scholar: lookup
  7. Königová A, Várady M, Corba J. Comparison of in vitro methods and faecal egg count reduction test for the detection of benzimidazole resistance in small strongyles of horses. Vet Res Commun 2003 May;27(4):281-8.
    doi: 10.1023/a:1024079907895pubmed: 12872828google scholar: lookup
  8. Authier S. Strongyle resistance to fenbendazole in horses. Can Vet J 2000 Apr;41(4):268.
    pubmed: 10769763
Subscribe to our newsletter
Join 99,383 horse owners like you who receive our email updates on horse health and nutrition.