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Veterinary parasitology1984; 15(1); 75-83; doi: 10.1016/0304-4017(84)90112-2

The prevalence and intensity of internal parasites of horses in the U.S.A.

Abstract: Fifty-five adult horses were necropsied over a 15-month period, and their worm burdens counted and speciated. Twenty-one species of Cyathostominae were recovered. Ten species: Cyathostomum catinatum, Cylicocyclus nassatus, Cylicostephanus longibursatus, Cyathostomum coronatum, Cylicostephanus goldi, C. calicatus, C. minutus, Cylicocyclus leptostomus, C. insigne and Cyathostomum pateratum, comprised 98.9% of the total cyathostome burdens. These same 10 species also demonstrated high prevalences in 4 previous surveys. Eight of these 10 species have been shown to be resistant to benzimidazole anthelmintics. Anthelmintic resistance apparently had little effect on the prevalence of a species, but appeared to increase its relative abundance within a mixed population. The prevalence of other internal parasites was similar to previous reports, but Strongylus vulgaris adults and arterial lesions were less common.
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Publication Date: 1984-07-01 PubMed ID: 6237483DOI: 10.1016/0304-4017(84)90112-2Google Scholar: Lookup
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  • Journal Article

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 involved necropsying 55 adult horses over a 15-month period to identify, count, and classify internal parasite species. The study found high prevalence and benzimidazole anthelmintic resistance in 10 species, and noted less frequent occurrence of Strongylus vulgaris and related arterial lesions compared to previous surveys.

Methodology and Species Identified

  • The study involved a post-mortem examination (necropsy) of 55 adult horses over a period of 15 months. During this necropsy, worm burdens were counted and identified or speciated.
  • The research identified 21 species of Cyathostominae, a subfamily of small strongyles or redworms that are common internal parasites in horses.
  • Out of these 21 species, 10 were found to comprise 98.9% of the total cyathostome burdens, including Cyathostomum catinatum, Cylicocyclus nassatus, Cylicostephanus longibursatus, Cyathostomum coronatum, Cylicostephanus goldi, C. calicatus, C. minutus, Cylicocyclus leptostomus, C. insigne and Cyathostomum pateratum.

Prevalence and Anthelmintic Resistance

  • The same 10 species were found to display high prevalence in four previous studies, suggesting their dominant presence in the horse population studied.
  • The study discovered that eight out of the 10 dominant species have shown resistance to benzimidazole anthelmintics, a class of deworming agents commonly used to control parasite burdens in horses.
  • The research presents an interesting finding, noting that anthelmintic resistance doesn’t appear to affect the prevalence of a particular species. Instead, it was found to increase the relative abundance of that species in a mixed population, suggesting that resistance may allow these species to thrive amidst anthelmintic treatment.

Prevalence of Other Parasites

  • The prevalence of other internal parasites found in the horses was largely in line with the findings of previous studies, suggesting a consistent pattern of parasitic colonization in these animals.
  • The study noted that the prevalence of Strongylus vulgaris adults, a species of large strongyles, and the occurrence of arterial lesions related to this parasite were less common compared to surveys conducted in the past.

Cite This Article

APA
Reinemeyer CR, Smith SA, Gabel AA, Herd RP. (1984). The prevalence and intensity of internal parasites of horses in the U.S.A. Vet Parasitol, 15(1), 75-83. https://doi.org/10.1016/0304-4017(84)90112-2

Publication

Veterinary parasitology
ISSN: 0304-4017
NlmUniqueID: 7602745
Country: Netherlands
Language: English
Volume: 15
Issue: 1
Pages: 75-83

Researcher Affiliations

Reinemeyer, C R
    Smith, S A
      Gabel, A A
        Herd, R P

          MeSH Terms

          • Animals
          • Antinematodal Agents / pharmacology
          • Drug Resistance
          • Female
          • Horse Diseases / epidemiology
          • Horse Diseases / parasitology
          • Horses
          • Male
          • Spirurida Infections / epidemiology
          • Strongyle Infections, Equine / drug therapy
          • Strongyle Infections, Equine / epidemiology
          • United States

          Citations

          This article has been cited 27 times.
          1. Šarkūnas M, Schwahn A, Suleimanova K. A pilot study on the potency of injectable vs. oral moxidectin formulation to suppress strongyle egg excretion in horses at twice lower dose. Helminthologia 2025 Jun;62(2):87-94.
            doi: 10.2478/helm-2025-0018pubmed: 41058774google scholar: lookup
          2. Lu Y, Ru P, Qin S, Zhang Y, Fu E, Cai M, Tuohuti N, Wu H, Zhang Y, Zhang Y. Epidemiological Patterns of Gastrointestinal Parasitic Infections in Equine Populations from Urumqi and Ili, Xinjiang, China. Vet Sci 2025 Jul 6;12(7).
            doi: 10.3390/vetsci12070644pubmed: 40711304google scholar: lookup
          3. Kuzmina TA, Königová A, Antipov A, Kuzmin Y, Kharchenko V, Syrota Y. Changes in equine strongylid communities after two decades of annual anthelmintic treatments at the farm level. Parasitol Res 2024 Nov 25;123(11):394.
            doi: 10.1007/s00436-024-08417-5pubmed: 39585485google scholar: lookup
          4. Kuzmina TA, Königová A, Burcáková L, Babjak M, Syrota Y. Strongylids of Domestic Horses in Eastern Slovakia: Species Diversity and Evaluation of Particular Factors Affecting Strongylid Communities. Acta Parasitol 2024 Jun;69(2):1284-1294.
            doi: 10.1007/s11686-024-00854-7pubmed: 38775915google scholar: lookup
          5. Matthews JB, Peczak N, Lightbody KL. The Use of Innovative Diagnostics to Inform Sustainable Control of Equine Helminth Infections. Pathogens 2023 Oct 11;12(10).
            doi: 10.3390/pathogens12101233pubmed: 37887749google scholar: lookup
          6. Boisseau M, Dhorne-Pollet S, Bars-Cortina D, Courtot É, Serreau D, Annonay G, Lluch J, Gesbert A, Reigner F, Sallé G, Mach N. Species interactions, stability, and resilience of the gut microbiota - Helminth assemblage in horses. iScience 2023 Feb 17;26(2):106044.
            doi: 10.1016/j.isci.2023.106044pubmed: 36818309google scholar: lookup
          7. Malsa J, Courtot É, Boisseau M, Dumont B, Gombault P, Kuzmina TA, Basiaga M, Lluch J, Annonay G, Dhorne-Pollet S, Mach N, Sutra JF, Wimel L, Dubois C, Guégnard F, Serreau D, Lespine A, Sallé G, Fleurance G. Effect of sainfoin (Onobrychis viciifolia) on cyathostomin eggs excretion, larval development, larval community structure and efficacy of ivermectin treatment in horses. Parasitology 2022 Sep;149(11):1439-1449.
            doi: 10.1017/S0031182022000853pubmed: 35929352google scholar: lookup
          8. Mathewos M, Teshome D, Fesseha H. Study on Gastrointestinal Nematodes of Equines in and around Bekoji, South Eastern Ethiopia. J Parasitol Res 2022;2022:8210160.
            doi: 10.1155/2022/8210160pubmed: 35677390google scholar: lookup
          9. Elmeligy E, Abdelbaset A, Elsayed HK, Bayomi SA, Hafez A, Abu-Seida AM, El-Khabaz KAS, Hassan D, Ghandour RA, Khalphallah A. Oxidative stress in Strongylus spp. infected donkeys treated with piperazine citrate versus doramectin. Open Vet J 2021 Apr-Jun;11(2):238-250.
            doi: 10.5455/OVJ.2021.v11.i2.8pubmed: 34307081google scholar: lookup
          10. Johnson ACB, Biddle AS. The Use of Molecular Profiling to Track Equine Reinfection Rates of Cyathostomin Species Following Anthelmintic Administration. Animals (Basel) 2021 May 9;11(5).
            doi: 10.3390/ani11051345pubmed: 34065099google scholar: lookup
          11. Mathewos M, Fesseha H, Yirgalem M. Study on Strongyle Infection of Donkeys and Horses in Hosaena District, Southern Ethiopia. Vet Med (Auckl) 2021;12:67-73.
            doi: 10.2147/VMRR.S297951pubmed: 33791192google scholar: lookup
          12. Slivinska K, Klich D, Yasynetska N, Żygowska M. The Effects of Seasonality and Group Size on Fecal Egg Counts in Wild Przewalski's Horses (Equus Ferus Przewalskii, Poljakov, 1881) in The Chernobyl Exclusion Zone, Ukraine During 2014 - 2018. Helminthologia 2020 Dec;57(4):314-321.
            doi: 10.2478/helm-2020-0042pubmed: 33364900google scholar: lookup
          13. Bellaw JL, Nielsen MK. Meta-analysis of cyathostomin species-specific prevalence and relative abundance in domestic horses from 1975-2020: emphasis on geographical region and specimen collection method. Parasit Vectors 2020 Oct 12;13(1):509.
            doi: 10.1186/s13071-020-04396-5pubmed: 33046130google scholar: lookup
          14. Barlaam A, Traversa D, Papini R, Giangaspero A. Habronematidosis in Equids: Current Status, Advances, Future Challenges. Front Vet Sci 2020;7:358.
            doi: 10.3389/fvets.2020.00358pubmed: 32719812google scholar: lookup
          15. Saeed MA, Beveridge I, Abbas G, Beasley A, Bauquier J, Wilkes E, Jacobson C, Hughes KJ, El-Hage C, O'Handley R, Hurley J, Cudmore L, Carrigan P, Walter L, Tennent-Brown B, Nielsen MK, Jabbar A. Systematic review of gastrointestinal nematodes of horses from Australia. Parasit Vectors 2019 Apr 29;12(1):188.
            doi: 10.1186/s13071-019-3445-4pubmed: 31036059google scholar: lookup
          16. Attia MM, Khalifa MM, Atwa MT. The prevalence and intensity of external and internal parasites in working donkeys (Equus asinus) in Egypt. Vet World 2018 Sep;11(9):1298-1306.
            doi: 10.14202/vetworld.2018.1298-1306pubmed: 30410237google scholar: lookup
          17. Tedla M, Abichu B. Cross-sectional study on gastro-intestinal parasites of equids in South-western Ethiopia. Parasite Epidemiol Control 2018 Nov;3(4):e00076.
            doi: 10.1016/j.parepi.2018.e00076pubmed: 30364581google scholar: lookup
          18. Peachey LE, Pinchbeck GL, Matthews JB, Burden FA, Lespine A, von Samson-Himmelstjerna G, Krücken J, Hodgkinson JE. P-glycoproteins play a role in ivermectin resistance in cyathostomins. Int J Parasitol Drugs Drug Resist 2017 Dec;7(3):388-398.
            doi: 10.1016/j.ijpddr.2017.10.006pubmed: 29121562google scholar: lookup
          19. Schuster RK, Sivakumar S. The larval development of Habronema muscae (Nematoda: Habronematidae) affects its intermediate host, Musca domestica (Diptera: Muscidae). Parasitol Res 2017 Feb;116(2):503-509.
            doi: 10.1007/s00436-016-5312-ypubmed: 27817010google scholar: lookup
          20. Schneider S, Pfister K, Becher AM, Scheuerle MC. Strongyle infections and parasitic control strategies in German horses - a risk assessment. BMC Vet Res 2014 Nov 12;10:262.
            doi: 10.1186/s12917-014-0262-zpubmed: 25387542google scholar: lookup
          21. Al Anazi AD, Alyousif MS. Prevalence of non-strongyle gastrointestinal parasites of horses in Riyadh region of Saudi Arabia. Saudi J Biol Sci 2011 Jul;18(3):299-303.
            doi: 10.1016/j.sjbs.2011.02.001pubmed: 23961139google scholar: lookup
          22. Kuzmina TA, Lyons ET, Tolliver SC, Dzeverin II, Kharchenko VA. Fecundity of various species of strongylids (Nematoda: Strongylidae)--parasites of domestic horses. Parasitol Res 2012 Dec;111(6):2265-71.
            doi: 10.1007/s00436-012-3077-5pubmed: 22903448google scholar: lookup
          23. Lyons ET, Kuzmina TA, Tolliver SC, Collins SS. Observations on development of natural infection and species composition of small strongyles in young equids in Kentucky. Parasitol Res 2011 Dec;109(6):1529-35.
            doi: 10.1007/s00436-011-2460-ypubmed: 21614543google scholar: lookup
          24. Hinney B, Wirtherle NC, Kyule M, Miethe N, Zessin KH, Clausen PH. Prevalence of helminths in horses in the state of Brandenburg, Germany. Parasitol Res 2011 May;108(5):1083-91.
            doi: 10.1007/s00436-011-2362-zpubmed: 21472400google scholar: lookup
          25. Traversa D, Iorio R, Klei TR, Kharchenko VA, Gawor J, Otranto D, Sparagano OA. New method for simultaneous species-specific identification of equine strongyles (nematoda, strongylida) by reverse line blot hybridization. J Clin Microbiol 2007 Sep;45(9):2937-42.
            doi: 10.1128/JCM.00714-07pubmed: 17626168google scholar: lookup
          26. Hodgkinson JE, Freeman KL, Lichtenfels JR, Palfreman S, Love S, Matthews JB. Identification of strongyle eggs from anthelmintic-treated horses using a PCR-ELISA based on intergenic DNA sequences. Parasitol Res 2005 Mar;95(4):287-92.
            doi: 10.1007/s00436-004-1289-zpubmed: 15682337google scholar: lookup
          27. Höglund J, Ljungström BL, Nilsson O, Lundquist H, Osterman E, Uggla A. Occurrence of Gasterophilus intestinalis and some parasitic nematodes of horses in Sweden. Acta Vet Scand 1997;38(2):157-65.
            doi: 10.1186/BF03548495pubmed: 9257451google scholar: lookup
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