Mortality in horses refers to the incidence and causes of death within equine populations. Understanding mortality is important for assessing health risks, improving management practices, and guiding veterinary care. Various factors contribute to mortality in horses, including age, breed, health status, and environmental conditions. Common causes of death in horses include colic, injury, infectious diseases, and age-related conditions. Mortality rates and patterns can vary significantly depending on the population and geographic location. This page compiles peer-reviewed research studies and scholarly articles that investigate the epidemiology, causes, and trends of mortality in horses, providing insights into preventive measures and management strategies to reduce mortality rates.
Pearson H, Pinsent PJ, Denny HR, Waterman A.The indications for laparotomy in 140 horses are analysed, with particular emphasis on the operative or autopsy findings in 82 cases of colic. In cases of exploratory laparotomy, the overall recovery rate was only 28 per cent but 48 of the 82 animals were considered to have inoperable lesions. The recovery rate and causes of death for each indication are briefly reviewed.
Whitlock RH, Dellers RW, Shively JN.A three-week-old Arabian filly was admitted to the Large Animal Hospital with a respiratory disorder and died despite symptomatic treatment. The necropsy lesions were suggestive of viral pneumonia. An equine adenovirus were isolated from nasal and pharyngeal swabs and from several tissues after death. Typical adenovirus virions were demonstrated by electron microscopy.
Wagenaar G.A description is given of three cases in which horses died very shortly after being given an intramuscular injection of iron dextran. The use of iron dextran in the case of horses is inadvisable.
Harris WF.Three horses exhibited nervous and cardiopulmonary signs after ingestins small amounts of metaldehyde, and 2 died in 3 to 5 hours. A colt given 0.1 mg/kg was similarly affected and died.
Jones RS.Surgical repair of a cleft palate was carried out in three horses. Mandibular symphisotomy allowed adequate exposure of the defect. The first subject, a young foal died from inhalation pneumonia but the other two made satisfactory recoveries. The problems of closure of the lip and symphysis are discussed.
Thompson DB, Studdert MJ, Beilharz RG, Littlejohns IR.A fatal syndrome of certain Arabian foals which begins at about 25 days of age (range 14 to 46 days) and which runs a course of about 23 days (range 13 to 42 days) is described. The syndrome, which affected 17 foals on a single farm is further characterised by pneumonia, in some instances by dermatitis (dermatophilosis) and other infections, together with a progressive decline in health till death at about 49 days of age (range 34 to 77 days), despite intensive therapy. Four of the foals, on histopathological evidence, had adenviral pneumonia, in 2 foals there was histopathological evidence of...
Fitzgerald WE.Four cases of snakebite in horses are presented. Diagnosis was made on clinical signs in all, plus fang punctures in 2 cases. Tiger snake antivenene was used in the treatment of 2 patients and these recovered rapidly. Of the 2 in which antivenene was not used, 1 severely affected horse died. The clinical signs which were observed were those of progressive general paralysis and were entirely referable to the neurotoxic component of the venom.
McGuire TC, Poppie MJ, Banks KL.Thirty sick Arabian foals and 78 clinically normal Arabian foals were examined for combined (B- and T-lymphocyte) immunodeficiency. Diagnosis was based on lymphocyte counts and serum immunoglobulin (Ig) content or microscopic examination of lymphoid organs. Ten of the 30 sick foals and 2 of the 78 clinically normal foals had combined immunodeficiency. The 2 affected foals in the group of 78 subsequently developed fatal pneumonia.
Lymphocyte counts were made from 9 of the 12 immunodeficient foals; the range was 0 to 936/cmm., whereas the normal mean was 4,119/cmm., with a standard deviation ...
Littlejohn A.The mortality following operations for intestinal obstructions in horses decreased from 80 per cent during the period 1849-1913 to 22 per cent during the period 1934-1964. Mortality following operations for high intestinal obstructions was greater than for low intestinal obstructions, and the mortality following operations for strangulating obstructions was more than twice as great as the mortality following simple obstructions. The most frequent cause of death following operations was failure to correct the causal condition, or subsequent impaction.
The anaesthesia techniques most frequently...
Crawford AE, Picken LK, Gabriel FD, Quade J, Gould S.Equestrian sports continue to gain popularity in the United States and are associated with a high injury rate, especially involving the central nervous system and thorax. Due to this high rate of injury and the potential for long-term consequences associated with participation, an understanding of the unique risks of this sport is needed. Unassigned: To describe severe injury in equestrian sports and review the role that protective gear plays in injury mitigation. Unassigned: The PubMed Database was searched using the search terms "equestrian" and "horse" combined with "spinal cord injury," "h...
Ellerbrock M, Krohn J, Büttner K, Wehrend A.Dystocia is rare in horses, but is life-threatening for mares and foals. Therefore, veterinary research depends on up-to-date data to optimise equine dystocia management. In addition, knowledge of the prognosis of equine dystocia is necessary to advise animal owners. This retrospective study of equine dystocia aimed to enrich existing datasets with up-to-date information. For the first time, the focus was on the causes of dystocia that occurred alone or in combination. Over a period of 10 years, 72 cases of dystocia were analysed using a standardised, predetermined diagnosis code. Results: Of ...
Rutberg AT, Grams KA.Wildlife managers and the public have expressed considerable interest in the use of contraception to help manage the populations of wild horses and burros (Equus caballus and E. asinus). Field testing has shown that two preparations of the porcine zona pellucida (PZP) vaccine, a simple emulsion (ZonaStat-H) and PZP-22 (which supplements ZonaStat-H with a controlled-release component) effectively prevent pregnancy in individual mares and can substantially reduce population foaling rates. To determine whether some PZP preparations might have secondary effects that harm treated mares or their foa...
Allen SE, Taylor S, Given J, Verheyen KL.The British horseracing industry is committed to reducing equine fatalities in jump racing. Race-related fatalities are a major welfare concern and threaten the sport's social licence to operate. Objective: To describe the risk of, and determine risk factors for, fatality in British jump racing. Methods: Retrospective cohort. Methods: Analyses included all starts made in British jump races between January 2010 and April 2023. Available information for each horse, race, racecourse, trainer and jockey was collated and combined with details of all fatalities recorded by official veterinary office...
Rossi HS, Hyytiäinen HK, Junnila JJT, Rajamäki MM, Mykkänen AK.Pneumonia is a common condition in ailing neonatal foals, and it remains an important cause of morbidity and mortality in this veterinary patient group. Factors affecting the survival of young foals with pneumonia have not been thoroughly investigated. The aim of this study was to explore the potential prognostic factors associated with survival of these foals. Fifty foals under one month of age with pneumonia were included in this retrospective clinical study. The foals were divided into groups based on survival (survived to discharge or died/euthanised during hospitalisation). Multiple clini...
Orozco Lopez D, Garcia-Lopez JM, Carpenter R, Bras JJ, Richardson DW, Ortved KF.To describe the outcome of metacarpophalangeal (MCPJ) and proximal interphalangeal joint (PIPJ) arthrodesis using a locking compression-distal femur plate (LCP-DFP) in Thoroughbred racehorses with traumatic disruption of the suspensory apparatus (TDSA) at risk of PIPJ subluxation. Methods: Multicenter retrospective study. Methods: Twenty-six Thoroughbred racehorses. Methods: Records of Thoroughbred racehorses with TDSA that had undergone MCPJ and PIPJ arthrodesis using an LCP-DFP at three referral hospitals between 2020 and 2024 were reviewed for inclusion. The preoperative data collected incl...
Simões BP, Cerri FM, Takahira RK, Borges AS, Oliveira-Filho JP, Amorim RM.Chlorfenapyr is a pesticide that interferes with mitochondrial function, leading to cell death and mortality. Although poisoning is primarily documented in humans and dogs, it can result in severe clinical signs, including sweating, respiratory distress, and neurological dysfunction. This report describes the clinical and laboratory findings of a horse with suspected accidental intoxication with chlorfenapyr. A 4-year-old Quarter Horse mare was referred to the veterinary hospital with signs of excessive sweating, hyperthermia, tachypnea, muscle fasciculation, and fearful facial expression. The...
Kamr AM, Bartish C, Summers J, Horton J, Hostnik LD, Orr K, Browne N, Dembek KA, Saliba C, Gomez DE, Toribio RE.Information about the association of antimicrobial peptides with hypovitaminosis D in hospitalized foals is lacking. Objective: We aimed to longitudinally determine the association of serum concentrations of vitamin D metabolites, vitamin D binding protein (DBP), and parathyroid hormone (PTH) with antimicrobial peptides (β-defensin-1 and cathelicidin-1) and the mRNA expression of the vitamin D receptor (VDR), 1α-hydroxylase (CYP27B1), 24-hydroxylase (CYP24A1), toll-like receptor-4 (TLR-4), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), disease severity, and mortality in hospita...
Slavik K, Bender S, Sharkey L, Nolen-Walston R.Renal lipidosis is a well-documented histologic finding in humans and small animals with renal and metabolic disorders, but it is not well described in equids. Objective: To describe the signalment, clinicopathologic indices, and postmortem findings of equids with a histologic diagnosis of both hepatic and renal lipidosis (HL + RL) and compare them to cases with hepatic lipidosis only (HL). Methods: Equids with necropsy findings of renal or hepatic lipidosis (state diagnostic lab) between 2008 and 2022. Methods: Retrospective case-control study. Signalment, history, necropsy diagnosis, and...
Bennet ED, Parkin TDH.The Equine Injury Database (EID) is a census-level record of Thoroughbred racing in North America, currently recording 95.6% of all race starts in 2023, along with partial training and veterinary histories of each horse. Objective: To identify horse-, race- and track-level risk factors associated with race-related fatal musculoskeletal injury (MSI) of Thoroughbred racehorses in North America. Methods: Retrospective cohort study. Methods: The study cohort included all race starts made by horses born after 31 December 2006, at tracks that fully report to the EID and consisted of 3,851,659 race s...
Loppnow Z, Kersh K, Wang C, Spaethe S, Troy J.The clinical outcomes in horses diagnosed with established synovial sepsis (SS) or minimally contaminated synovial wounds (SW)/non-established sepsis, following intravenous regional limb perfusion (IVRLP) treatment, have not been reported since 2010. Additionally, previous reports on this subject were confined to just two clinical retrospective reports. This study aimed to provide an update on the short-term (hospital discharge) and long-term (≥1 year) survival rates in adult horses diagnosed with SS or SW treated with IVRLP at a single institution in the USA from 2010-2020. The study also...
Cameron-Whytock HA, O'Brien D, Lewis V, Parkin T, Bennet ED.To date, industry and research outputs that have aimed to improve safety in equestrian eventing have tended to focus on identifying risk factors for horse falls during cross-country, which have been identified as the greatest risk of injury and fatality for riders. There is an absence of research that investigates fatalities of horses within the sport of eventing. Objective: To use a combination of media reports and eventing federation databases to describe and document equine fatalities in equestrian eventing, including their context, location and a basic pathology. Methods: Descriptive study...
Aleman M, McCue M, Bellone RR.Fatal anesthesia-induced malignant hyperthermia (MH) and rhabdomyolysis with hyperthermia documented in Quarter Horses (QH) breeds are caused by a missense variant in the ryanodine receptor 1 gene (RYR1: XP_023505430.1.:p.(R2454G), designated as MH). The reported cases to date have all been heterozygous, and the allele frequency is suspected to be low. Objective: To determine an accurate estimate of MH allele frequency in multiple horse breeds and investigate whether homozygous animals exist in the population. Methods: In total, 159 227 horses from 16 breeds who were either submitted for cli...
Swezey E, Szydziak E, Angus LDG, Mehta V, Cardozo-Stolberg S.Equestrian trauma is recognized as a high-risk injury mechanism with the potential for significant morbidity and mortality. Although horse-related injuries are more frequently seen in a rural environment, they can also occur in urban settings. Urban physicians should be mindful of these potential cases. Methods: A retrospective review was performed on all patients treated at Nassau University Medical Center, East Meadow, New York, for equestrian-related trauma from January 1, 2000, to December 31, 2024. Results: Twenty-nine equestrian trauma patients ages 10-70 were included, with injuries ob...
Bianchi D, Santos RRD, Peleja PL, de Sousa ABB, da Silva Evangelista M, de Almeida Júnior JS, Barata LES, Moraes WP, Minervino AHH. (tropical horse tick) is a tick species commonly found parasitizing horses and other equids in the Amazon region, causing economic losses. Currently, tick control is based on chemical acaricides, usually in a power formulation for topical use. However, its indiscriminate use results in the emergence of resistant tick lineages. Several plant compounds have been tested for their acaricide activity. In the Amazon, several plants are used for oil extraction, resulting in the production of solid residue (waste) that may contain chemical molecules with biological activities. Thus, we aimed to test ...
Death studiesMay 28, 2025
1-11 doi: 10.1080/07481187.2025.2510477
Kaufman SVA, Nieforth LO.For practitioners involved in equine-assisted services (EAS), the death of a horse can be a significant life disruption. This study aims to understand the communicative resilience processes that equine-assisted service practitioners express following the death of an equine in their program. This study analyzed secondary qualitative data from a cross-sectional online survey completed by 84 participants. Analysis revealed practitioners engaged in all five communicative resilience processes following the death of an equine in their program. This research extends current resilience research by exa...
Avison A, Physick-Sheard PW, Pyle WG.This paper reviews the myocardial substrate of horses relative to that of humans and discusses the utility of performance horses as a model of exercise-associated cardiac arrhythmias and sudden cardiac death in athletes. The coronary circulation is similar between the species while coronary artery anomalies and myocardial bridging appear to only be associated with athletic mortality in human athletes and not in performance horses. There are subtle differences in the histology of the sinus and atrioventricular nodes, of unknown clinical significance, while the His bundle is more highly innervat...
Chaipokam J, Rojnuckarin P.In Thailand, stem cell transplantation and horse antithymocyte globulin (ATG) are not accessible for most adult aplastic anemia (AA) patients. Alternative therapies are required. We conducted a cohort study of 110 adult AA patients treated with oxymetholone alone for at least 30 days from 2013 to 2023. Response at month 6 and prognostic factors were evaluated. The mean age was 63.4 years old and 58.2% were female. Severe and very severe AA (SAA/VSAA) comprised 64.5% and 3.6%, respectively. The initial oxymetholone daily dose was 150 mg in 66.4%. The overall response was 56.4% (50.7% for SAA/V...
Kelemen Z, Vogl C, Torres Borda L, Auer U, Jenner F.Clinical care for patients with limited life expectancy often requires adjustments, prioritizing immediate benefits over long-term outcomes, as the relevance of future complications diminishes. This study identifies indicators of mortality risk in horses with chronic orthopaedic conditions to enhance individualized care and welfare. Over 3 years, 123 chronically lame horses and 6 healthy control horses at an animal sanctuary underwent regular (every 3 months) comprehensive health assessments and activity monitoring using wearable sensors. Data collected included body condition scores, muscul...
Boocock H, Flyps J, Escobar A, Redondo JI, Taylor PM, Gozalo-Marcilla M, Johnston GM, Bettschart-Wolfensberger R, Sullivan R.Equid anaesthetic mortality is of interest to practitioners. Data for donkey and hybrid mortality have not been specifically described. The main aim of this worldwide observational, prospective, multicentre cohort study was to report on mortality in the 7 days following a general anaesthetic or standing sedation in donkeys and hybrids. This study hypothesised that donkeys and hybrids would have higher mortalities compared to horses. Data were collected as part of the fourth Confidential Enquiry into Perioperative Equine Fatalities (CEPEF4). A total of 825 cases were included, with 757 donkeys ...
Fielding CL.To describe the signalment, diagnosis, treatment, and laboratory characteristics of horses with hyperchloremia and identify factors associated with the magnitude of the increased chloride concentration. Unassigned: Horses with a chloride concentration greater than 108 mEq/L were included in this retrospective study. Descriptive statistics and multiple linear regression analysis were used to identify associations between diagnosis, treatment, and laboratory variables and the magnitude of hyperchloremia. Unassigned: 134 horses met the inclusion criteria for this study. Creatinine was a significa...
Faircloth J, Fielding L, Epstein K, Crabtree N, Mochal C, Magdesian G, Major D.To describe the clinical presentation of horses with synchronous diaphragmatic flutter (SDF) and identify clinical and laboratory variables associated with survival. Methods: Retrospective study from January 2004 to September 2022. Methods: Five large animal referral hospitals in the United States. Methods: Thirty-seven horses of various breeds and ages presenting with clinical signs of SDF, excluding animals participating in an endurance competition. All horses were >1 year of age. Methods: None. Results: Variables recorded and analyzed included signalment, clinical and laboratory data, trea...
Sjolin E, Espinosa D, Arroyo L, Kenney D, Lack A, Baird J.Listeriosis is caused by , a Gram-positive, facultative anaerobic, intracellular rod bacterium that can infect a wide variety of species. Listeriosis occurs in a diverse range of domestic and wild animals but is most commonly a disease of ruminants. Clinical signs include meningoencephalitis, typhlocolitis, septic arthritis, and abortions. Listeriosis in horses has been reported in several countries but is an uncommon diagnosis. This report describes clinical, bacteriological, histopathological, and immunohistochemical findings in 6 foals with neonatal septicemia from which was isolated. Key ...
Nocera I, Cingottini D, Di Franco C, Sala G, Bindi F, Spadari A, Rinnovati R, Vitale V, Jose-Cunilleras E, Sgorbini M.Several studies investigated risk and prognostic parameters for horses with colic; however, the consensus is still debated. The present work aimed to investigate colic outcomes and to identify risk factors in horses referred for colic. In this multicenter retrospective study, 236 clinical records of equids referred for colic at three different equine centers were reviewed. The following data were collected: history, signalment, physical examination at the time of admission, hematological and biochemical analysis, diagnosis, SIRS status and 0-6 point-scale SIRS score, colic type, treatment atte...
Kamr A, Fortin-Trahan R, Arroyo LG, Hostnik LD, Gomez DE, Toribio RE.Hypocalcemia is frequent in horses with colitis. Information on serum parathyroid hormone (PTH) concentrations and its association with bone turnover biomarkers in horses with colitis is lacking. We aimed to determine the association between serum bone resorption biomarkers (C-terminal telopeptide of type I collagen [CTX-I]) and bone formation (osteocalcin [OCN]) with blood PTH, total calcium (tCa), ionized calcium (iCa), phosphorus (Pi), and total magnesium (tMg) concentrations, and mortality in horses with acute colitis. A total of 163 horses were divided into colitis (n = 127) and healt...
Markowitz JS.Equibase (EQB) race charts provide the official record of North American Thoroughbred races and often document catastrophic injury, euthanasia, or equine-ambulance transport. Because chart documentation and regulatory classification differ, fatalities occurring > 72 hours after a race fall outside international regulatory definitions applied by the Equine Injury Database (EID) and may not appear in EID aggregates. EQB charts confirm horse identity, race participation, finishing status, and last recorded start. Horseracing Wrongs (HRW), an advocacy group, publishes horse-level fatality data tha...
Boeger L, Volkmann N, Probst J, Kemper N, Venner M.The emergence of antimicrobial resistance raises concerns about using antibiotics in veterinary medicine, particularly in cases of bronchopneumonia in foals diagnosed early based on a screening programme. Many subclinical foals recover spontaneously, thus, interest in more restrictive antibiotic usage is increasing. Objective: To determine whether initiating antimicrobial therapy at a later stage of bronchopneumonia decreases antimicrobial usage without compromising successful resolution of pathology in affected foals. Methods: A total of 1200 warmblood foals born in 2020, 2022, 2023 and 2024 ...
Bindi F, de Marchi L, Elias-Cortajarena A, Sala G, Vitale V, Spadari A, Rinnovati R, Bonelli F, Sgorbini M.Colic is a major cause of morbidity and mortality in horses, with oxidative stress implicated in its pathophysiology. Objective: Evaluate biomarkers (BIOs) of oxidative stress and antioxidant defense in healthy horses and those with non-strangulating colic (NSC) and strangulating colic (SC) and assess correlations with survival. Methods: Seventy-one adult horses: 10 healthy and 61 colic-affected (42 NSC, 19 SC) admitted to 3 veterinary teaching hospitals. Methods: Prospective, multicenter cohort study. Blood samples were collected at admission (T0) and up to 96 h post-admission. Biomarkers me...
Cerullo A, Scilimati N, Di Nicola MR, Colla L, Mazza S, Bertoletti A, Nannarone S, Gialletti R.Left dorsal displacement of the large colon (LDDLC) is a common cause of colic in horses and it is frequently associated with recurrent episodes, with significant implications for horse management, athletic performance, and owner satisfaction. Laparoscopic nephrosplenic space (NSS) ablation is a preventive surgical technique aimed at reducing recurrence in horses with a history of medically or surgically treated LDDLC. This retrospective study evaluated 48 horses that underwent laparoscopic NSS ablation in two Italian Veterinary Teaching Hospitals between 2016 and 2024. Short-term outcomes, in...
van den Brom-Spierenburg AJ, Siegers EW, Westermann CM, Vernooij JCM, Sloet van Oldruitenborgh-Oosterbaan MM, Theelen MJP.In hospitalized foals, limited data are available on the utility of sequential measurement of SAA concentrations and the value of these data in a clinical setting. Objective: To determine serum amyloid A (SAA) concentrations in ill neonatal foals at multiple timepoints during hospitalization, and to evaluate a potential association with systemic inflammatory response syndrome (SIRS) status, blood culture (BC) result, and survival. Methods: Hospitalized ill foals (n = 90, ≤ 14 days). Methods: In this retrospective study, foals were classified based on SIRS criteria: "SIRS" or "NonSIRS," ...
