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Equine veterinary journal2010; 43(3); 324-331; doi: 10.1111/j.2042-3306.2010.00164.x

Sudden death in racing Thoroughbred horses: an international multicentre study of post mortem findings.

Abstract: To improve the understanding of exercise related sudden death in Thoroughbred racehorses. Objective: To describe the post mortem findings in cases of sudden death associated with exercise in 268 Thoroughbred racehorses. Methods: Gross and histological post mortem findings of 268 cases of sudden death were collated and reviewed. Cases originated from 6 racing jurisdictions around the world. Sudden death was defined as acute collapse and death in a closely observed and previously apparently healthy Thoroughbred racehorse, during, or within one hour after, exercise. Cause of death as determined by the attending pathologist was categorised as definitive, presumptive or unexplained and compared between the different populations. Cardiopulmonary lesions recorded at post mortem examination were compared between different populations. Results: Pathologists recorded a definitive cause of death in 53% (143/268) of cases. Major definitive causes of sudden death included cardiac failure, apparent pulmonary failure, pulmonary haemorrhage, haemorrhage associated with pelvic fractures or with idiopathic blood vessel rupture, and spinal cord injury. A presumptive cause of death was made in 25% (67/268) of cases and death remained unexplained in 22% (58/268) of cases. There were several statistically significant inter-population differences in the cause of death and in reporting of cardiopulmonary lesions. Conclusions: Sudden death can be attributed to a variety of causes. Causes of sudden death and the lesions found in cases of exercise-related sudden death are similar in different racing jurisdictions. However, the lesions are often not specific for the cause of death and determination of the cause of death is therefore affected by interpretation by the individual pathologist.
© 2010 EVJ Ltd.
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Publication Date: 2010-09-14 PubMed ID: 21492210DOI: 10.1111/j.2042-3306.2010.00164.xGoogle Scholar: Lookup
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  • Journal Article
  • Multicenter Study
  • 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.

This research article is about a post-mortem study conducted on Thoroughbred racehorses who suddenly died during or shortly after exercise, with the goal of improving understanding of sudden exercise-related death in these horses.

Objective and Methods

The study aimed to analyze and describe the post-mortem findings in 268 cases of Thoroughbred racehorse sudden deaths associated with exercise. These horses were closely observed and deemed healthy prior to their sudden collapse and death, either during or within an hour after exercise. The cases were collected from six different racing jurisdictions globally. The findings, both gross and histological, of the horses were reviewed and collated. The cause of death, as determined by the attending pathologist, was categorized as definitive, presumptive, or unexplained. These causes were then compared among the different populations. Additionally, cardiopulmonary lesions recorded at the post-mortem examination were compared among the different populations.

  • A definitive cause of death was recorded by pathologists in 53% (143/268) of cases
  • A presumptive cause of death was determined in 25% (67/268) of cases
  • Death remained unexplained in 22% (58/268) of cases

Major Findings

Primary definitive causes of sudden death identified in the study included cardiac failure, apparent pulmonary failure, pulmonary haemorrhage, haemorrhage linked with pelvic fractures or with inexplicable blood vessel rupture, and spinal cord injury.

Statistically significant differences were found between populations in the cause of death and the reported cardiopulmonary lesions. Despite these differences, the study found the causes of sudden death and the lesions identified in cases of exercise-associated sudden death to be similar across the different racing jurisdictions.

Conclusions

The study concluded that sudden death in Thoroughbred racehorses could be attributed to a variety of causes. However, the research also recognized that the lesions found are often not specific to the cause of death. This non-specificity influences the determination of the cause of death as it is often dependent on the individual pathologist’s interpretation. Despite the variations in individual interpretations, the study affirmed the similarities of sudden death causes and identified lesions across different horse racing jurisdictions.

Cite This Article

APA
Lyle CH, Uzal FA, McGorum BC, Aida H, Blissitt KJ, Case JT, Charles JT, Gardner I, Horadagoda N, Kusano K, Lam K, Pack JD, Parkin TD, Slocombe RF, Stewart BD, Boden LA. (2010). Sudden death in racing Thoroughbred horses: an international multicentre study of post mortem findings. Equine Vet J, 43(3), 324-331. https://doi.org/10.1111/j.2042-3306.2010.00164.x

Publication

Equine veterinary journal
ISSN: 0425-1644
NlmUniqueID: 0173320
Country: United States
Language: English
Volume: 43
Issue: 3
Pages: 324-331

Researcher Affiliations

Lyle, C H
  • Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Veterinary Centre, UK. catriona.lyle@ed.ac.uk
Uzal, F A
    McGorum, B C
      Aida, H
        Blissitt, K J
          Case, J T
            Charles, J T
              Gardner, I
                Horadagoda, N
                  Kusano, K
                    Lam, K
                      Pack, J D
                        Parkin, T D
                          Slocombe, R F
                            Stewart, B D
                              Boden, L A

                                MeSH Terms

                                • Animals
                                • Central Nervous System / injuries
                                • Death, Sudden / etiology
                                • Death, Sudden / veterinary
                                • Female
                                • Heart Diseases / complications
                                • Heart Diseases / veterinary
                                • Horse Diseases / etiology
                                • Horses
                                • Lung Diseases / complications
                                • Lung Diseases / veterinary
                                • Male
                                • Physical Conditioning, Animal
                                • Shock, Hemorrhagic / complications
                                • Shock, Hemorrhagic / veterinary

                                Citations

                                This article has been cited 37 times.
                                1. Bennet ED, Parkin TDH. Anomalous Incidence of Fatal Musculoskeletal Injury in North American 2-Year-Old Thoroughbred Racehorses in the Year 2020. Animals (Basel) 2023 Aug 9;13(16).
                                  doi: 10.3390/ani13162572pubmed: 37627362google scholar: lookup
                                2. Brito G, Damián JP, Suárez G, Ruprechter G, Trigo P. Characterization of Raid Hipico Uruguayo Competencies by Ride Type: Causes of Death and Risk Factors. Animals (Basel) 2023 May 10;13(10).
                                  doi: 10.3390/ani13101602pubmed: 37238032google scholar: lookup
                                3. Gibson MJ, Legg KA, Gee EK, Rogers CW. The Reporting of Racehorse Fatalities in New Zealand Thoroughbred Flat Racing in the 2011/12-2021/22 Seasons. Animals (Basel) 2023 Feb 9;13(4).
                                  doi: 10.3390/ani13040612pubmed: 36830402google scholar: lookup
                                4. McCrae P, Spong H, Golestani N, Mahnam A, Bashura Y, Pearson W. Validation of an Equine Smart Textile System for Heart Rate Variability: A Preliminary Study. Animals (Basel) 2023 Feb 1;13(3).
                                  doi: 10.3390/ani13030512pubmed: 36766401google scholar: lookup
                                5. Cullinane A, Garvey M, Walsh C, Gibbons J, Creighton A. A Scoping Review of Non-Structural Airway Disease as a Cause of Poor Performance in Racehorses. Animals (Basel) 2023 Jan 27;13(3).
                                  doi: 10.3390/ani13030429pubmed: 36766318google scholar: lookup
                                6. McCrae P, Spong H, Rutherford AA, Osborne V, Mahnam A, Pearson W. A Smart Textile Band Achieves High-Quality Electrocardiograms in Unrestrained Horses. Animals (Basel) 2022 Nov 23;12(23).
                                  doi: 10.3390/ani12233254pubmed: 36496775google scholar: lookup
                                7. Rocchigiani G, Verin R, Uzal FA, Singer ER, Pregel P, Ressel L, Ricci E. Pulmonary bleeding in racehorses: A gross, histologic, and ultrastructural comparison of exercise-induced pulmonary hemorrhage and exercise-associated fatal pulmonary hemorrhage. Vet Pathol 2022 Nov;59(6):973-982.
                                  doi: 10.1177/03009858221117859pubmed: 35972142google scholar: lookup
                                8. Nath L, Stent A, Elliott A, La Gerche A, Franklin S. Risk Factors for Exercise-Associated Sudden Cardiac Death in Thoroughbred Racehorses. Animals (Basel) 2022 May 18;12(10).
                                  doi: 10.3390/ani12101297pubmed: 35625143google scholar: lookup
                                9. Ter Woort F, Dubois G, Tansley G, Didier M, Verdegaal L, Franklin S, Van Erck-Westergren E. Validation of an equine fitness tracker: ECG quality and arrhythmia detection. Equine Vet J 2022 Feb 9;55(2):336-43.
                                  doi: 10.1111/evj.13565pubmed: 35138653google scholar: lookup
                                10. Hellings IR, Skjerve E, Karlstam E, Valheim M, Ihler CF, Fintl C. Racing-associated fatalities in Norwegian and Swedish harness racehorses: Incidence rates, risk factors, and principal postmortem findings. J Vet Intern Med 2022 Mar;36(2):778-786.
                                  doi: 10.1111/jvim.16364pubmed: 35060194google scholar: lookup
                                11. Vera L, Muylle S, Van Steenkiste G, Segers P, Decloedt A, Chiers K, van Loon G. Histological and biomechanical properties of systemic arteries in young and old Warmblood horses. PLoS One 2021;16(7):e0253730.
                                  doi: 10.1371/journal.pone.0253730pubmed: 34252105google scholar: lookup
                                12. Nath LC, Elliott AD, Weir J, Curl P, Rosanowski SM, Franklin S. Incidence, recurrence, and outcome of postrace atrial fibrillation in Thoroughbred horses. J Vet Intern Med 2021 Mar;35(2):1111-1120.
                                  doi: 10.1111/jvim.16063pubmed: 33604980google scholar: lookup
                                13. Goto Asakawa M, Mehmood W, Ali M, Oikawa MA. Idiopathic multifocal myocardial atrophy with fibrosis and fatty infiltration involving Purkinje fibres in a 13-year-old Arabian broodmare: Histopathological features. Vet Med Sci 2021 Jan;7(1):3-8.
                                  doi: 10.1002/vms3.350pubmed: 32940417google scholar: lookup
                                14. Cherdchutham W, Koomgun K, Singtoniwet S, Wongsutthawart N, Nontakanun N, Wanmad W, Petchdee S. Assessment of cardiac variables using a new electrocardiography lead system in horses. Vet World 2020 Jun;13(6):1229-1233.
                                  doi: 10.14202/vetworld.2020.1229-1233pubmed: 32801577google scholar: lookup
                                15. Vera L, Campos Arias D, Muylle S, Stergiopulos N, Segers P, van Loon G. A 1D computer model of the arterial circulation in horses: An important resource for studying global interactions between heart and vessels under normal and pathological conditions. PLoS One 2019;14(8):e0221425.
                                  doi: 10.1371/journal.pone.0221425pubmed: 31433827google scholar: lookup
                                16. Tapprest J, Foucher N, Linster M, Laloy E, Cordonnier N, Amat JP, Hendrikx P. Resumeq: A Novel Way of Monitoring Equine Diseases Through the Centralization of Necropsy Data. Front Vet Sci 2019;6:135.
                                  doi: 10.3389/fvets.2019.00135pubmed: 31134214google scholar: lookup
                                17. Poole DC, Erickson HH. Exercise-induced pulmonary hemorrhage: where are we now?. Vet Med (Auckl) 2016;7:133-148.
                                  doi: 10.2147/VMRR.S120421pubmed: 30050846google scholar: lookup
                                18. Li M, Chadda KR, Matthews GDK, Marr CM, Huang CL, Jeevaratnam K. Cardiac electrophysiological adaptations in the equine athlete-Restitution analysis of electrocardiographic features. PLoS One 2018;13(3):e0194008.
                                  doi: 10.1371/journal.pone.0194008pubmed: 29522557google scholar: lookup
                                19. Gimenez F, Hines SA, Evanoff R, Ojo KK, Van Voorhis WC, Maly DJ, Vidadala RSR, Mealey RH. In vitro growth inhibition of Theileria equi by bumped kinase inhibitors. Vet Parasitol 2018 Feb 15;251:90-94.
                                  doi: 10.1016/j.vetpar.2017.12.024pubmed: 29426483google scholar: lookup
                                20. Gunther-Harrington CT, Arthur R, Estell K, Martinez Lopez B, Sinnott A, Ontiveros E, Varga A, Stern JA. Prospective pre- and post-race evaluation of biochemical, electrophysiologic, and echocardiographic indices in 30 racing thoroughbred horses that received furosemide. BMC Vet Res 2018 Jan 18;14(1):18.
                                  doi: 10.1186/s12917-018-1336-0pubmed: 29347921google scholar: lookup
                                21. Shave R, Howatson G, Dickson D, Young L. Exercise-Induced Cardiac Remodeling: Lessons from Humans, Horses, and Dogs. Vet Sci 2017 Feb 12;4(1).
                                  doi: 10.3390/vetsci4010009pubmed: 29056668google scholar: lookup
                                22. Mellor DJ, Beausoleil NJ. Equine Welfare during Exercise: An Evaluation of Breathing, Breathlessness and Bridles. Animals (Basel) 2017 May 26;7(6).
                                  doi: 10.3390/ani7060041pubmed: 28587125google scholar: lookup
                                23. Tapprest J, Morignat E, Dornier X, Borey M, Hendrikx P, Ferry B, Calavas D, Sala C. Fallen stock data: An essential source of information for quantitative knowledge of equine mortality in France. Equine Vet J 2017 Sep;49(5):596-602.
                                  doi: 10.1111/evj.12664pubmed: 28079926google scholar: lookup
                                24. Flethøj M, Kanters JK, Pedersen PJ, Haugaard MM, Carstensen H, Olsen LH, Buhl R. Appropriate threshold levels of cardiac beat-to-beat variation in semi-automatic analysis of equine ECG recordings. BMC Vet Res 2016 Nov 28;12(1):266.
                                  doi: 10.1186/s12917-016-0894-2pubmed: 27894294google scholar: lookup
                                25. Raftery AG, Garcia NC, Thompson H, Sutton DG. Arrhythmogenic right ventricular cardiomyopathy secondary to adipose infiltration as a cause of episodic collapse in a horse. Ir Vet J 2015;68:24.
                                  doi: 10.1186/s13620-015-0052-3pubmed: 26500762google scholar: lookup
                                26. Pedersen PJ, Thomsen KB, Olander ER, Hauser F, Tejada Mde L, Poulsen KL, Grubb S, Buhl R, Calloe K, Klaerke DA. Molecular Cloning and Functional Expression of the Equine K+ Channel KV11.1 (Ether à Go-Go-Related/KCNH2 Gene) and the Regulatory Subunit KCNE2 from Equine Myocardium. PLoS One 2015;10(9):e0138320.
                                  doi: 10.1371/journal.pone.0138320pubmed: 26376488google scholar: lookup
                                27. Hinchcliff KW, Couetil LL, Knight PK, Morley PS, Robinson NE, Sweeney CR, van Erck E. Exercise induced pulmonary hemorrhage in horses: American College of Veterinary Internal Medicine consensus statement. J Vet Intern Med 2015 May-Jun;29(3):743-58.
                                  doi: 10.1111/jvim.12593pubmed: 25996660google scholar: lookup
                                28. Avison A, Goderre BG, Pyle WG, Physick-Sheard PW. QT Interval and Cardiac Restitution Ratio Complexity in Standardbred Racehorses From Rest to Maximal Effort: Insights Into Arrhythmia Risk. J Vet Intern Med 2025 Sep-Oct;39(5):e70207.
                                  doi: 10.1111/jvim.70207pubmed: 40926462google scholar: lookup
                                29. Uldahl M, Mellor DJ. Regulatory Integrity and Welfare in Horse Sport: A Constructively Critical Perspective. Animals (Basel) 2025 Jun 30;15(13).
                                  doi: 10.3390/ani15131934pubmed: 40646833google scholar: lookup
                                30. Avison A, Physick-Sheard PW, Pyle WG. Performance horses as a model for exercise-associated cardiac arrhythmias and sudden cardiac death. J Mol Cell Cardiol Plus 2025 Jun;12:100452.
                                  doi: 10.1016/j.jmccpl.2025.100452pubmed: 40475708google scholar: lookup
                                31. Gómez-Torres F, Ballesteros-Acuña L, Ruíz-Sauri A. Histological and morphometric changes in cardiac conduction fibers after spontaneous myocardial infarction in horses and dogs. Vet World 2025 Apr;18(4):827-836.
                                  doi: 10.14202/vetworld.2025.827-836pubmed: 40453948google scholar: lookup
                                32. Cameron-Whytock HA, O'Brien D, Lewis V, Parkin T, Bennet ED. Equine fatalities in equestrian eventing. Equine Vet J 2025 Sep;57(5):1387-1394.
                                  doi: 10.1111/evj.14529pubmed: 40371753google scholar: lookup
                                33. Bennet ED, Parkin TDH. Novel risk factors associated with fatal musculoskeletal injury in Thoroughbreds in North American racing (2009-2023). Equine Vet J 2026 Jan;58(1):20-30.
                                  doi: 10.1111/evj.14503pubmed: 40134143google scholar: lookup
                                34. Kapusniak A, Nath L, Hebart M, Franklin S. Heritability of sudden cardiac death in Thoroughbred racehorses. Equine Vet J 2025 Mar;57(2):325-332.
                                  doi: 10.1111/evj.14130pubmed: 38984817google scholar: lookup
                                35. Tharwat M, Al-Sobayil F, Ali H. Changes in the hematobiochemical, acid-base and blood gas elements as well as biomarkers of inflammation and bone metabolism in donkeys (Equus asinus) with acute bleeding. Open Vet J 2024 May;14(5):1146-1153.
                                  doi: 10.5455/OVJ.2024.v14.i5.8pubmed: 38938441google scholar: lookup
                                36. Gómez-Torres F, Ballesteros-Acuña L, Ruíz-Sauri A. Histopathological changes in the electrical conduction of cardiac nodes after acute myocardial infarction in dogs and horses, compared with findings in humans: A histological, morphometrical, and immunohistochemical study. Vet World 2023 Oct;16(10):2173-2185.
                                  doi: 10.14202/vetworld.2023.2173-2185pubmed: 38023272google scholar: lookup
                                37. Kelly-Bosma M, Henning J, Haworth M, Ploeg R, Woolford L, Neef A, Das S, Allavena R. A Multicentre Epidemiologic Study of Sudden and Unexpected Death in Adult Cats and Dogs in Australia. Vet Sci 2023 Sep 20;10(9).
                                  doi: 10.3390/vetsci10090582pubmed: 37756104google scholar: lookup
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