Diagnosis and prognosis in horses with acute abdominal pain (colic)

Projektleder: Tina Holberg Pihl, e-mail: thpi@sund.ku.dk

Collection of peritoneal fluid via abdominocentesis. Biomarkers are measured in both blood and peritoneal fluid from horses with acute abdominal pain (colic).

Acute abdominal pain (colic) has a high incidence and morbidity among horses. Fast decisions needs to be taken regarding treatment and prognosis in order to ensure survival of the horse or decide for euthanasia in due time.

Colic is caused by different gastro-intestinal diseases with varying degrees of intestinal tissue damage. This tissue damage creates local and systemic inflammatory and haemostatic reactions that can be measured as concentration changes in a number of different biomarkers (acute phase proteins (SAA, Fibrinogen and haptoglobin), Gc-globulin, D-dimer, lactate and others) in blood and peritoneal fluid.

Our research focus on how measurement of biomarkers in blood and peritoneal fluid can help the clinicians to differentiate between specific diseases, take decision for correct treatment and to evaluate the prognosis of the individual horse.

Currently our research focus on the Equine bloodworm (Strongylus vulgaris), the most pathogenic parasite in horses.

Diagnosis and prevention of Strongylus vulgaris infection and disease

The Equine bloodworm, Strongylus (S.) vulgaris causes arteritis, thrombosis of mesenteric arteries and intestinal infarcts, which may lead to colic, intestinal rupture and death of the horse.

Our research aims to identify novel diagnostic biomarkers of migrating S. vulgaris and associated vascular injury and thrombosis in order to achieve early diagnosis and reduce the number of horses dying because of S. vulgaris.

We have investigated novel inflammatory biomarkers in blood and peritoneal fluid as well as hemostatic changes with novel methods in horses infected with S. vulgaris and horses with disease associated with S. vulgaris.

Currently we are identifying and describing miRNAs excreted from migrating S. vulgaris larvae and miRNAs from the horse associated to vascular injury and thrombosis.

Perspectives of the research

Knowledge about the investigated biomarkers concentrations and kinetics in horses with different acute gastrointestinal diseases will improve the ability to institute the correct treatment early in the disease state and inform the owner of the prognosis for the horse.

Our research in S. vulgaris has already led to improved awareness, understanding of disease mechanisms, and improved diagnosis of disease associated to S. vulgaris. This has led to a reduced number of horses suffering and dying because of S. vulgaris in Denmark.

Our ongoing research of MiRNAs excreted by S. vulgaris in the blood are promising and will hopefully lead to early diagnostic markers of migrating S. vulgaris and possible targets for future preventive immune modulating therapies or vaccines.

Improved diagnostic tools will support the legislative prescription-only use of anthelmintic drugs and reduce the risk of parasites developing resistance to available drugs.

Partners on the project

Department of Veterinary Clinical Medicine, University of Copenhagen (UC):

Department of Veterinary Health, UC:

Aarhus University, Department of Clinical Medicine:

Kentucky University, M.H. Gluck Equine Research Center:

Swedish Agricultural University (SLU), Department of Biomedical Science and Veterinary Public Health:

Evidensia Djursjukhuset Helsingborg


The research has been generously supported by the following funds:

  • The Danish Horse Levy Fund (Hesteafgiftsfonden)
  • The Independent Research Fund Denmark (Danmarks Frie Forskningsfund sagsnr. 0136-001B)
  • Hartman Fonden
  • Sveland stiftelsen


Results from the project are continuously disseminated to both equine veterinarians, horse owners, veterinary students and researchers. Below is a list of publications, presentations and online material. Links to the material are given when possible.

PhD theses:

  1. J. Honoré. Elucidating hemostatic aberrations in horses with migrating Strongylus vulgaris larvae with and without clinical disease. PhD thesis. University of Copenhagen. 2022
  2. Toft. MicroRNA as a diagnostic biomarker of the equine bloodworm, Strongylus vulgaris. Will be submitted October 31.th 2024.

Scientific conference abstracts with presentations:

  1. Toft, N. Ripley, B. Fromm, S. Cirera, M.K. Nielsen L.N. Nielsen, P.L. Nejsum, S. M. Thamsborg, T.H. Pihl. Are microRNAs possible biomarkers of bloodworm infection in horses? European Congress of Equine Internal Medicine (ECEIM), Rome, Oct. 2022. 
  1. Poulsen*, F.V. Henriksson; M. Dahl, M.L.Honoré, S.N. Olsen; P.S. Leifsson, S. Jacobsen, T.H. Pihl. Differentiation of Strongylus vulgaris-associated non-strangulating intestinal infarctions from colitis and idiopathic peritonitis. 11th Equine infectious disease conference, (online). Sep. 2021.
  2. J. Honoré*, M.K.Nielsen, L.N. Nielsen, T.H. Pihl. The application of the Calibrated Automated Thrombogram assay and plasma Thromboelastography in horses with migrating Strongylus vulgaris larvae. 11th Equine infectious disease conference, (online) Sep. 2021.
  3. Winther*, S. Haugaard*, T.H. Pihl, S. Jacobsen. Neutrophil Gelatinase-associated Lipocalin in Serum and Peritoneal Fluid from Horses with Abdominal Disease. 13th International Equine Colic Research Symposium, (online) Sep. 2021. https://beva.onlinelibrary.wiley.com/doi/10.1111/eve.23_13534?af=R
  4. Toft*, M.L. Honoré, B. Fromm, B. Whitehead, M.K. Nielsen, L.N. Nielsen, P.L. Nejsum, S. M. Thamsborg, T.H. Pihl. Profiling of microRNA secreted by the Equine Bloodworm (Strongylus vulgaris). 28th International conference of the world association for the advancement of veterinary parasitology (WAAVP), 2021.
  5. L. Honoré*, T.H. Pihl, L.N. Nielsen. Evaluation of the Calibrated Automated Thrombogram assay and plasma Thromboelastography for detection of hypercoagulability in horses with gastrointestinal disease. Joint congress of veterinary pathology and veterinary clinical pathology, Sep. 2019, Arnhem, Netherlands

 Peer reviewed scientific publications:

  1. Poulsen, F.V. Henriksson; M. Dahl, M.L.Honoré, S.N. Olsen; P.S. Leifsson, S. Jacobsen, T.H. Pihl. Differentiating Strongylus vulgaris-associated non-strangulating intestinal infarctions from idiopathic peritonitis and acute colitis in horses. Vet Record (2022). https://doi.org/10.1002/vetr.2538.
  2. Winther, S. Haugaard, T.H. Pihl, S. Jacobsen. Concentrations of neutrophil gelatinase-associated Lipocalin in serum and peritoneal fluid from horses with inflammatory abdominal disease and non-strangulating intestinal infarctions. Eq Vet J (2022). https://doi.org/10.1111/evj.13603
  3. Honoré, M.L., Pihl, T.H., Busk-Anderson, T.M. et al.Investigation of two different human d-dimer assays in the horse. BMC Vet Res 18, 227 (2022). https://doi.org/10.1186/s12917-022-03313-5
  4. J. Honoré, T.H. Pihl, L.N. Nielsen (2021). A pilot study evaluation of the Calibrated Automated Thrombogram assay and application of plasma-thromboelastography for detection of haemostatic aberrations in horses with gastrointestinal disease. BMC Vet research. DOI:10.1186/s12917-021-03058-7
  5. H. Pihl, M. K. Nielsen, S. N. Olsen, P.S. Leifsson, S. Jacobsen. Nonstrangulating intestinal infarctions associated with Strongylus vulgaris: Clinical presentation and treatment outcomes of 30 horses (2008–2016) - Pihl - 2018 - Equine Veterinary Journal - Wiley Online Library 
  1. H. Pihl, M.K. Nielsen, S. Jacobsen (2017). Changes in hemostasis in foals naturally infected with Strongylus vulgaris. J Equine Vet Sci , 54, 1-7. https://doi.org/10.1016/j.jevs.2017.02.002 
  1. Nielsen, M.K., Jacobsen, S., Olsen, S.N., Pihl, T.H. (2016). Non-strangulating intestinal infarction associated with Strongylus vulgaris in referred Danish equine patients. Equine Vet J, 48, 376-379. https://doi.org/10.1111/evj.12422
  2. H. Pihl, S. N. Olsen, S. Jacobsen, M. K. Nielsen (2016). Strongylus vulgaris - ”Blodormen” – dræber igen. Dyrlægen, 6/2016. Dyrlægen 6 by Fagmagasinet DYRLÆGEN - Issuu

Online publications for horse owners:

  1. Shaila Ann Sigsgaard og T. Pihl (2023): Værd at vide om kolik hos heste Det vi ved - Uanvendelig eller Ridehest
  2. Helle Kristensen, T. Pihl og Katrine Toft. Hestens parasitter. Hestens parasitter - Uanvendelig eller Ridehest
  3. Helle Kristensen og T. Pihl. Hestens. Blodormen – Den stille dræber er tilbage. Blodorm hos heste – den stille dræber - Uanvendelig eller Ridehest

Presentations for Equine veterinarians, horse owners and Sponsors:

  1. Pihl, T.H. Forbedret diagnostik og prognose af alvorlig kolik forårsaget af hestens blodorm – Effektvurdering til Hesteafgiftsfonden.
  2. Pihl, T.H and Toft, K, Strongylus vulgaris – Hestens blodorm og Generelle anbefalinger til ormeprofylakse, Heste ERFA møde Sjælland, Nov. 2022
  3. Toft, K. & Pihl, T.H. Parasite panel discussion - Parasite strategies in DK and challenges wit vulgaris. Nordic Equine Veterinary Conference, March 2022. ONLINE.
  4. Pihl, T.H*.: Hestens vigtigste parasitter. Herning Hingstekåring. Marts 2019, DK
  5. Pihl, T.H*.: Ormerelateret kolik hos heste. Hillerød Horse Show, Sep 2018, Hillerød, DK
  6. Pihl, T.H*.: Non-strangulerende intestinal infarkter associeret med Strongylus vulgaris. Danske Hestedyrlægers møde, Maj 2018, Skanderborg, DK
  7. Pihl, T.H*.: Ormerelateret kolik hos heste. SEGES Hestekongres, Jan 2018, Kolding, DK
  8. Pihl, T.H*.: Hestens vigtigste parasitter - Sygdom, diagnostik, behandling og profylakse. Veterinær sygeplejerskernes årsmøde, Nov. 2017, Middelfart, DK