Technical Information
The Small Redworm Blood Test should only be used after reading the supporting guidelines
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This test diagnoses cyathostomin infection in horses. The test is an ELISA format which detects IgG(T) antibodies specific to three selected recombinant antigens, representing the most common cyathostomin species, as well as all developmental life cycle stages in the host, including the clinically important encysted larvae.
Validation of the Small Redworm Blood Test (published in the International Journal for Parasitology in 2024)
Validation was conducted using gold standard samples obtained from horses for which cyathostomin total worm burden (TWB) data were available. High sensitivities and specificities were attained at TWB thresholds of 1,000, 5,000 and 10,000 cyathostomins, with area under the curve (AUC) values of Receiver Operator Characteristic (ROC) curves ranging from 0.91-0.96 for the three cyathostomin burden thresholds. ROC-AUC values of >0.9 are universally considered as defining tests with excellent diagnostic performance. For further information on the test’s performance parameters at different TWB thresholds, please refer to Small Redworm Blood Test guidelines document available at the link above.
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​​Uses of the Small Redworm Blood test
The test can be used by veterinarians to:
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Diagnose cyathostomin infection in individual horses to inform anthelmintic treatment decisions, especially in low infection risk situations where owners are still considering an annual treatment with a ‘larvicidal’ anthelmintic.
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Assess cyathostomin infection prevalence in groups of horses.
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Support differential diagnosis in gastrointestinal cases, in particular, to ‘rule-out’ the involvement of cyathostomins.
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​More information on how to use the test in practice can be accessed by clicking the link above.
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Limitations
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The test does not provide information about the exact numbers of cyathostomins present within an individual, but provides a 'serum score' result which relates to three different TWB thresholds (1,000, 5,000 and 10,000 cyathostomins). The 'serum score' must not be used as a standalone result, but must be interpreted with reference to an assessment of infection risk.
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The test is not recommended for use in horses assessed to be at moderate to high risk of helminth infection, based on a full risk assessment including environmental factors and previous FEC results.
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Antibody levels in blood reduce over time in response to treatment so the test cannot be used to monitor anthelmintic efficacy. It has been demonstrated that blood antibody levels are not reduced to low levels until at least 4 months after treatment and this can be complicated by horses becoming reinfected after treatment.
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​Testing recommendations
The Small Redworm Blood Test should only be applied in horses after reading the guidelines (accessible at the link at the top of the page) specifically developed for use of the test in practice. Use of the small redworm blood test in low risk populations effectively reduces anthelmintic use with data showing that 62% of a sport horse cohort (n=981) had serum scores below the lowest cyathostomin burden threshold (1,000 worms), with only 19% of horses exceeding the 10,000 worm burden threshold.
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Peer reviewed publications
Several peer-reviewed research papers and reviews have been published describing the development, validation, and application of the small redworm blood test. These are as follows:
1. Lightbody KL, Austin A, Lambert PA, von Samson-Himmelstjerna G, Jürgenschellert L, Krücken J, Nielsen MK, Sallé G, Reigner F, Donnelly CG, Finno CJ, Walshe N, Mulcahy G, Housby-Skeggs N, Grice S, Geyer KK, Austin CJ, Matthews JB. 2024. Validation of a serum ELISA test for cyathostomin infection in equines. Int J Parasitol. 54:23-32.
This paper describes the final steps in the optimisation, tech transfer, and validation of the commercial test. The results in this paper were, in part, used to establish the guidelines for using this test for informing anthelmintic treatments in groups of horses defined as being at low risk of strongyle infection.
Validation of a serum ELISA test for cyathostomin infection in equines - ScienceDirect
2. Matthews JB, Peczak N, Engeham S. 2024. An update on the latest developments in testing for equine helminths. In Practice 46:34-41.
This review describes how to integrate the small redworm blood test into sustainable worm control approaches for horses and includes new data on the use of the test in practice.
3. Matthews JB, Peczak N, Lightbody KL. 2023. The use of innovative diagnostics to inform sustainable control of equine helminth infections. Pathogens 12:1233.
This review summarises the development of the test, how to use it in practice, and includes specific information on how to apply the test in practice.
The Use of Innovative Diagnostics to Inform Sustainable Control of Equine Helminth Infections
4. Matthews JB, Austin CJ. 2023. Using diagnostics in supporting sustainable worm control in horses. UK Vet Equine 7:2-6.
This review discusses the use of diagnostic tests in modern worm control programmes and how to integrate these tests for effective worm control. This review includes new data on the performance of the small redworm blood test in low-infection-risk horses.
Using diagnostics in supporting sustainable worm control in horses | UK-Vet Equine
5. Tzelos T, Geyer K, Mitchell M, McWilliam, Kharchenko VO, Burgess STG, Matthews JB. 2020. Characterisation of serum IgG(T) responses to potential diagnostic antigens for equine cyathostomins. Int J Parasitol. 50:289-298.
This research describes the selection of the recombinant antigen components that comprise the cocktail of proteins that are used in the small redworm blood test.
6. Mitchell MC, Tzelos T, Handel I, McWilliam HEG, Hodgkinson JE, Nisbet AJ, Kharchenko VO, Burgess STG, Matthews JB. 2016.
Development of a recombinant protein-based ELISA for diagnosis of larval cyathostomin infection. Parasitology 143:1055-1066.
This paper describes the full characterisation of the GALA antigen, which is represented by two components in the small redworm blood test.
7. McWilliam HEG, Nisbet AJ, Dowdall SMJ, Hodgkinson JE, Matthews JB. 2010. Identification and characterisation of a potential immunodiagnostic marker for larval cyathostominosis. Int J Parasitol. 40:265-275.
This paper describes how the proteins in the small redworm blood test were discovered using molecular techniques.
8. Matthews JB, Hodgkinson JE, Dowdall SMJ, Proudman CJ. 2004. Recent developments in research into the Cyathostominae and Anoplocephala perfoliata. Vet Res. 35:371-381.
This review explains the rationale and concepts behind the development of the small redworm blood test.
9. Dowdall SMJ, Proudman CJ, Klei TR, Mair TS, Matthews JB. 2004. Antigen-specific IgGT responses as a marker for larval cyathostomin infection. Int J Parasitol. 34:101-108.
This paper describes the full characterisation of IgG(T) responses in horses to antigens derived from cyathostomins that underpinned the molecular biology studies that identified the proteins used in the small redworm blood test.
10. Dowdall SMJ, Proudman CJ, Love S, Murphy D, Klei TR, Matthews JB. 2003. Purification and analysis of the specificity of two putative diagnostic antigens for larval cyathostomin infection in horses. Res Vet Sci. 75:223-229.
This paper describes the serum antibody responses to purified antigen complexes that contain the proteins that were subsequently isolated by molecular means for the development of the small redworm blood test.
11. Dowdall SMJ, Matthews JB, Murphy D, Love S, Proudman CJ. 2002. Antigen-specific IgG(T) responses in natural and experimental cyathostomin infection. Vet Parasitol. 106:225-242.
This first paper describes the characterisation of the type of antibody response to cyathostomins that would provide the basis for the development of the small redworm blood test.
12. Matthews JB, Mair TS. 2025. Sustainable control of cyathostomin infections in practice. Eq. Vet. Ed. DOI: 10.1111/eve.14182.
This review summarises the epidemiology, clinical impact and management of cyathostomins and discusses the integration of small redworm blood testing into sustainable control strategies for control of these important parasites.
https://beva.onlinelibrary.wiley.com/doi/pdf/10.1111/eve.14182
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13. The small redworm blood test data generated in some of the papers listed above provided the foundation for IP to support the granting of a multi-territorial patent to Moredun Research Institute. WO2010112836 EQUINE PARASITE DETECTION