Musculoskeletal Injuries: What the Research Says

Evidence from 40 peer-reviewed studies

3 Systematic Review

17 Cohort Study

5 Case Report

15 Expert Opinion

What Professionals Should Know

•MicroRNA profiling is not yet ready for clinical application in predicting fractures in horses; continue relying on established imaging and epidemiological methods
•Research in equine molecular biomarkers is still in early stages—standardized protocols for sample handling, exercise controls, and data normalization are needed before clinical utility can be achieved
•Future fracture prevention strategies in racehorses should not depend on miRNA biomarkers until study designs are harmonized and findings become reproducible across independent research groups
•Allogeneic MSCs appear to be a safe treatment alternative to autologous MSCs for equine musculoskeletal injuries based on emerging evidence, potentially offering faster treatment availability
•Banked allogeneic cell products could reduce the interval between injury diagnosis and treatment initiation compared to autologous MSC harvesting
•Current evidence does not clearly support one approach over the other; treatment choice should consider individual case factors, cell availability, and cost until larger definitive trials are completed
•PRP efficacy varies substantially depending on study design—be cautious when evaluating claims as clinical outcomes may differ from experimental results
•Current evidence supports PRP use in tendon and ligament lesions, but quality of evidence varies; consider study methodology when selecting treatment protocols
•Comparative analysis between equine and human studies suggests similar biological mechanisms, potentially allowing cross-species evidence application to clinical practice
•Long-distance air transportation appears to affect bone metabolism in racehorses; consider additional monitoring and conditioning protocols for international horses arriving to compete
•Bone turnover marker assessment may help identify high-risk international horses and guide injury prevention strategies before racing
•Local racing operations may require different injury prevention approaches compared to managing international competitors with altered bone physiology
•Fractures predominate in Thoroughbreds on dirt tracks while tendon injuries are common in Arabians on both surfaces—adjust training intensity and recovery protocols by breed and track type
•The carpal joint and distal forelimb structures are injury hotspots during racing; prioritize preventive conditioning and early detection of lameness in these areas
•Summer months (June-September) show peak injury rates—intensify track maintenance, monitor footing conditions closely, and consider adjusted training schedules during dry periods
•Use wearable stride-tracking technology to monitor cumulative skeletal fatigue and identify horses at elevated injury risk before lameness occurs
•Maintain moderate, consistent workload rates over 4-start preparation windows (0.25-0.75 range); avoid both extreme underwork and overwork as both increase injury risk
•Establish individual fatigue baselines during each horse's career and modify training intensity when fatigue accumulation rates rise, rather than waiting for clinical signs of injury
•Poor racing performance is the dominant concern triggering veterinary examination in flat racing—trainers and veterinarians should investigate systemic issues when horses underperform rather than assuming catastrophic injury
•Step-up in race class significantly increases incident risk; careful conditioning and gradual class progression may reduce injuries in Thoroughbred flat racers
•Epistaxis screening and exclusion protocols appear effective at reducing race-day bleeds, suggesting similar pre-entry health screening for other conditions could be beneficial
•Musculoskeletal injuries remain the leading cause of retirement—trainers and veterinarians should focus on injury prevention strategies and early detection to improve career longevity and voluntary retirement rates
•Nearly all retired racehorses can be successfully repurposed, but current industry lacks traceability and accountability systems; establish monitoring protocols to track welfare outcomes in horses' second careers
•Horses with declining racing form are more likely to be voluntarily retired; develop evidence-based criteria for optimal retirement timing to improve post-racing outcomes and prevent involuntary retirement due to injury
•Thoroughbred racehorses face dramatically higher attrition risk than Standardbreds, suggesting breed-specific management and injury prevention strategies are essential for TB racing programs
•Early career management is critical for Thoroughbreds given median attrition age of 4.2 years; implementing conditioning protocols and screening for musculoskeletal predisposition before racing career begins may reduce losses
•The high prevalence of musculoskeletal injuries in Thoroughbreds versus sudden death in Standardbreds indicates breed-specific monitoring priorities and potential need for different veterinary screening protocols between breeds
•Understanding lameness localization patterns in western performance horses can help inform preventive management strategies specific to this discipline
•This ten-year review provides baseline data on injury prevalence that can guide practitioners in recognizing common problem areas in western athletes
•Practitioners should consider discipline-specific demands when assessing lameness in performance horses
•Monitor cumulative monthly training distances and speeds; galloping >6000 m/month at high speed combined with high canter volumes significantly elevates fracture risk and should trigger review of training protocols
•Establish baseline training metrics for your facility to quantify exposure to bone fatigue loads and identify which horses exceed safe thresholds
•Use speed and distance data as practical proxies for calculating cumulative stride cycles—the primary driver of bone fatigue injuries in racehorses
•Two-year-old racehorses require age-specific injury prevention strategies, as their injury pattern and seasonal risk differ substantially from older horses
•Dorsal metacarpal disease and traumatic lacerations should be priority concerns for young horse trainers, while older horses need enhanced monitoring for ligament and tendon pathology
•Injury prognosis and return-to-work timelines should be tailored by injury type rather than assuming uniform recovery across all musculoskeletal conditions
•Thoroughbred and Quarter horse racing involves substantially higher mortality risk during competition; management strategies should focus on musculoskeletal injury prevention and identification of at-risk horses before race entry
•Standardbred racing demonstrates lower exercise-associated mortality likely due to longer preparation and gradual conditioning protocols—these management approaches merit investigation as models for risk reduction in other breeds
•Breed-specific mortality patterns reflect industry norms; veterinary and management practices should be tailored to each discipline's characteristics rather than applying one-size-fits-all welfare standards
•Serum biomarkers may offer a non-invasive screening tool to identify horses at higher risk of musculoskeletal injury before clinical signs appear
•Geographic validation of biomarker thresholds is important; predictive values from North American populations may not directly transfer to European racehorses
•Incorporating biomarker monitoring into pre-training or racing protocols could support injury prevention strategies in your operation
•Understanding the prevalence and types of race-day veterinary events enables racing veterinarians and practitioners to prioritize prevention strategies for the most common conditions
•Baseline epidemiological data from this large-scale study supports evidence-based approaches to improving racehorse welfare and reducing injury rates
•Results inform risk management protocols and can guide targeted interventions for specific injury types affecting flat racing Thoroughbreds
•Either the sternum or ilium can be used as a bone marrow harvest site for MSC therapy without compromising cell quality or therapeutic potential
•Choice of harvest site can be made based on clinical accessibility, patient comfort, and operator preference rather than cell biology considerations
•Clinicians need not be concerned about inferior cell characteristics if ilial or sternal approach is selected based on practical factors
•Lameness continues to be a major cause of lost training days in young racehorses—focus preventive efforts on musculoskeletal health
•Monitor training practices across yards to identify which management and conditioning protocols most effectively reduce injury rates
•Consider benchmarking your yard's injury rates against these UK data to identify areas for improvement in horse welfare and training efficiency
•Pressure algometry provides a practical, objective tool for documenting and tracking pain in the neck, back, and croup—useful for monitoring response to treatment or exercise modifications
•Baseline MNT values differ significantly between horses based on age, breed, sex, and fitness; establish individual baseline measurements rather than relying on population averages
•Symmetrical measurements across the midline are expected in healthy horses; asymmetrical thresholds may indicate regional pain or pathology worth investigating
•Sore shins and inflammatory airway disease are major limiting factors in young Thoroughbred training; early intervention and prevention strategies should be prioritized
•Sex differences in musculoskeletal injury rates suggest that colts and geldings may require modified training protocols or closer monitoring than fillies
•The poor financial return (5% of 2-year-olds and 17% of 3-year-olds covering costs) indicates systemic issues with training intensity, timing, or selection criteria that warrant review
•Forelimb soft tissue injuries, particularly affecting flexor tendons and suspensory ligaments, are the dominant injury pattern in racing — farriers and veterinarians should prioritize preventive strategies for these structures through surface selection and workload management
•Chase racing carries significantly higher injury and fatality risk (6-fold higher than flat racing) — owners and trainers must weigh these risks when selecting racing types and implement enhanced welfare protocols for jump racing
•Older horses carry substantially elevated injury risk — trainers should adjust training intensity and racing frequency based on age to mitigate this evidence-based risk factor
•Autologous MSC therapy may be less effective in geriatric horses (≥22 years) due to reduced cell proliferation capacity, potentially requiring alternative sourcing or treatment approaches for older patients
•MSC harvesting and expansion protocols should be optimized for horses over 18 years old, as standard cell expansion targets (10-100 million cells) may be difficult to achieve
•Consider sourcing MSCs from younger donor horses or exploring alternative cell therapy options when treating older patients requiring cell-based therapy
•Allogenic BM-MSCs from a characterized donor can be used clinically with a low adverse reaction rate (~4%), providing a practical alternative to autologous harvesting when rapid treatment is needed
•Be vigilant for post-injection reactions at injection sites, particularly increased pain, swelling, heat, or lameness, though these may be masked by routine anti-inflammatory therapy
•Recognize that synovitis and mild inflammatory reactions may be underreported in clinical practice and consider baseline imaging and careful monitoring when administering allogeneic cell therapy
•Objective volumetric measurement of distal limb swelling can supplement subjective visual assessments and help monitor training stress responses in individual horses
•Early detection of abnormal swelling patterns may help trainers and veterinarians modify work programs before lameness develops
•This technology offers a practical, affordable method for tracking limb changes over time, though measurement bias should be acknowledged and standardized user training recommended
•MSC therapies for joint disease will trigger an inflammatory response even in healthy joints; monitor for transient synovitis and lameness in the first 10 days post-injection
•Allogeneic MSC products may behave differently from autologous cells and require separate safety evaluation protocols
•Pre-injection and post-injection synovial fluid sampling may help distinguish MSC-induced inflammation from complications or adverse reactions
•Pole work is commonly used to restore joint motion during swing phase, but clinicians need to understand GRF changes to avoid aggravating healing injuries
•Quantifying ground reaction forces during pole trotting will help determine safe therapeutic parameters for rehabilitation protocols
•Results will inform whether pole work intensity should be modified for horses recovering from specific musculoskeletal conditions
•Biologic therapies (PRP, stem cells, scaffolds, growth factors) are advancing treatment options for tendon and ligament injuries beyond traditional rehabilitation protocols
•Multiple biologic approaches exist with varying mechanisms; understanding which therapy suits specific injury types and stages of healing is critical for clinical decision-making
•Gene therapy is emerging but remains largely experimental; focus your current practice on established biologics with documented clinical outcomes
•Prioritize prevention of superficial digital flexor tendon injuries through appropriate shoeing, training management, and ground surface selection for polo horses.
•Implement screening and monitoring protocols for EIPH and systemic conditions like myositis and rhabdomyolysis given their frequency in this discipline.
•Establish clear communication channels with veterinarians and follow association welfare guidelines to balance performance demands with horse health standards.
•IMU technology offers potential for early detection of developing musculoskeletal injuries in stabled horses through objective behaviour monitoring rather than relying on visual assessment alone
•Implementing automated behaviour monitoring systems could allow identification of lameness or pain before injuries become catastrophic, enabling earlier intervention
•This technology may be particularly valuable for racehorses where early detection could prevent career-ending or life-threatening injuries
•PRP products vary significantly in composition depending on preparation method and the individual horse's health status—standardization is needed before claiming equivalent clinical outcomes between different protocols
•Current evidence does not definitively support PRP as a disease-modifying treatment; use should be considered experimental and documented carefully in your practice
•When considering PRP, demand detailed product composition data (cell and cytokine counts) from suppliers, as this directly affects therapeutic potential but is often incompletely reported
•MSC therapy is emerging as a potential treatment for multiple equine conditions beyond joint and tendon injuries, but clinical protocols are not yet standardized for routine use
•The horse serves as a valuable translational model for human diseases due to similarities in disease pathogenesis, particularly for wound healing, laminitis, and metabolic disorders
•Current evidence supports further research but practitioners should await robust clinical trials before adopting MSC therapies for non-musculoskeletal conditions in their practice
•This model provides a non-invasive method to understand load distribution across multiple structures simultaneously, reducing reliance on invasive measurement techniques for injury investigation
•Trailing forelimb loading is greatest during canter, which may inform training and injury prevention strategies for cantering horses
•Peak ligament and tendon strains occurring at specific phases of stance can guide timing of diagnostic imaging and rehabilitation protocols
•While ESWT combined with MSC therapy is used clinically for tendon and ligament injuries, this in vitro study provides only preliminary cellular support—in vivo evidence is still needed before claiming synergistic benefits
•ESWT appears to enhance MSC metabolic activity and certain differentiation pathways in the laboratory, but translation to clinical tissue repair remains unproven
•The similar immunomodulatory effects between treated and untreated cells suggest ESWT does not compromise the immune-regulating benefits of MSC therapy
•PRP offers a more accessible alternative to stem cell therapy for managing osteoarthritis in horses, though standardization of preparation methods is needed
•Inconsistency in PRP production and application means clinical outcomes may vary; practitioners should be aware that evidence quality is still limited despite theoretical benefits
•Before investing in PRP treatments, verify the preparation protocol being used, as different methods produce substantially different products with potentially different efficacy
•Consider manual therapy referral for sport horses with chronic, recurring, or poorly responsive musculoskeletal problems before pursuing extensive diagnostics
•Manual therapies complement conventional care and address muscular, joint, and neurologic components that may be missed by standard veterinary examination alone
•Integration of manual therapy techniques with veterinary care may improve outcomes in performance horse management
•Control shipping conditions and handling protocols from cell isolation to delivery, as these directly impact cell viability and treatment success rates
•Be selective when combining MSC treatments with other products; some medications or additives can damage cells, so verify compatibility before use
•Follow evidence-based injection techniques and administration routes specific to the injury location, as these choices affect therapeutic outcomes
•Allogeneic MSC treatments using MHC-mismatched cells may have reduced efficacy due to immune-mediated rejection; consider autologous or MHC-matched sources when available
•Cytotoxic antibody responses to mismatched cells could limit the therapeutic window and require immunosuppressive protocols to extend cell survival
•When using allogeneic MSCs clinically, screening for MHC compatibility or preparing for potential immune rejection is important for treatment planning
•TGF-β2 pre-treatment of allogeneic MSCs shows potential to reduce immune rejection risk, but donor variability means individual testing may be necessary for clinical application
•While TGF-β2 reduces baseline MHC expression, it does not fully prevent inflammatory upregulation—additional strategies may be needed to maintain immune-evasive properties in the inflamed injured tissue
•TGF-β2 treatment increases MSC yield without compromising cell quality, which could improve economic feasibility of therapeutic MSC preparation
•Fusion imaging offers a new diagnostic tool to resolve cases where ultrasound findings are unclear or inconclusive, potentially improving diagnostic accuracy for equine soft tissue injuries.
•This technology could enhance interventional procedures by allowing real-time ultrasound guidance referenced to cross-sectional imaging, improving treatment precision.
•Early adoption of this imaging approach in equine practice may improve outcomes for complex musculoskeletal cases that are diagnostically challenging with ultrasound alone.
•ESWT is an available treatment option for lame horses; consult with specialized equine lameness centers for assessment and suitability
•This therapy should be integrated into a broader diagnostic and rehabilitation protocol rather than used in isolation
•Use scintigraphy to detect early musculoskeletal injuries before radiographs become positive, allowing earlier intervention in performance horses.
•Scintigraphy is valuable for localizing sources of chronic lameness when clinical signs are vague and radiographs are unremarkable.
•Understanding the three-phase imaging protocol and common pitfalls in acquisition and interpretation is critical for accurate clinical application and avoiding misdiagnosis.

Key Research Findings

Only 3 miRNA studies in equine musculoskeletal disease were identified, none specifically addressing stress fractures in horses

Lee Seungmee, 2021

Differentially expressed miRNAs in human osteoporotic fracture patients were inconsistent across studies, with conflicting results from target prediction programmes

Lee Seungmee, 2021

Exercise affected miRNA profiles in both species (miR-21 upregulated by endurance exercise; miR-125b downregulated by exercise)

Lee Seungmee, 2021

No miRNA profile has yet demonstrated reliable predictive capacity for fracture occurrence despite recent advances in molecular profiling

Lee Seungmee, 2021

In vitro and early in vivo studies showed potential for adverse immunological reactions with allogeneic MSCs in horses, but newer studies lack evidence of inflammatory reactions or adverse clinical responses

Colbath Aimée C, 2020

Allogeneic MSCs offer practical advantages including cell banking, reduced time to treatment, use of younger donor animals, and pre-treatment cell manipulation

Colbath Aimée C, 2020

Autologous MSCs remain widely used despite requiring longer collection times and individual cell harvest procedures

Colbath Aimée C, 2020

Large randomised controlled trials with detailed immunological evaluation are needed to definitively establish the relative safety and efficacy of allogeneic versus autologous MSCs

Colbath Aimée C, 2020

Systematic review of PRP efficacy in equine and human orthopedic therapy across multiple musculoskeletal lesion types

Brossi Patrícia M, 2015

Study design and methodology significantly influence reported efficacy outcomes of PRP treatments

Brossi Patrícia M, 2015

Evidence base includes randomized trials in humans, equine clinical studies, and experimental studies across animal species

Brossi Patrícia M, 2015

Review critically appraised available data on mechanisms of action and therapeutic effectiveness of PRP in tendons, ligaments, and joints

Brossi Patrícia M, 2015

International horses travelling long distances showed altered bone turnover markers compared to local horses

Ayodele Babatunde A, 2025

Bone turnover differences between groups may influence musculoskeletal injury risk in racehorses

Ayodele Babatunde A, 2025

Study conducted during Victorian Spring Racing Carnival to compare injury risks between populations

Ayodele Babatunde A, 2025

Evidence Base

Use of Omics Data in Fracture Prediction; a Scoping and Systematic Review in Horses and Humans.

Lee Seungmee, Baker Melissa E, Clinton Michael et al. (2021) — Animals : an open access journal from MDPI

Systematic Review

Mesenchymal stem cells for treatment of musculoskeletal disease in horses: Relative merits of allogeneic versus autologous stem cells.

Colbath Aimée C, Dow Steven W, McIlwraith C Wayne et al. (2020) — Equine veterinary journal

Systematic Review

Platelet-rich plasma in orthopedic therapy: a comparative systematic review of clinical and experimental data in equine and human musculoskeletal lesions.

Brossi Patrícia M, Moreira Juliana J, Machado Thaís S L et al. (2015) — BMC veterinary research

Systematic Review

Differences in bone turnover markers and injury risks between local and international horses: A Victorian Spring Racing Carnival study.

Ayodele Babatunde A, Pagel Charles N, Mackie Eleanor J et al. (2025) — Equine veterinary journal

Musculoskeletal Injuries: What the Research Says

What Professionals Should Know

Key Research Findings

Evidence Base

Use of Omics Data in Fracture Prediction; a Scoping and Systematic Review in Horses and Humans.

Mesenchymal stem cells for treatment of musculoskeletal disease in horses: Relative merits of allogeneic versus autologous stem cells.

Platelet-rich plasma in orthopedic therapy: a comparative systematic review of clinical and experimental data in equine and human musculoskeletal lesions.

Differences in bone turnover markers and injury risks between local and international horses: A Victorian Spring Racing Carnival study.

Distribution of race and training-related musculoskeletal injuries by track and location in Thoroughbred and Arabian racehorses.

The impact of cumulative bone fatigue on musculoskeletal injury risk in racing Thoroughbreds.

Race-Level Reporting of Incidents during Two Seasons (2015/16 to 2016/17) of Thoroughbred Flat Racing in New Zealand.

Appraising the Welfare of Thoroughbred Racehorses in Training in Queensland, Australia: The Incidence, Risk Factors and Outcomes for Horses after Retirement from Racing.

Attrition of Thoroughbred and Standardbred racehorses at New York Racetracks due to exercise and non-exercise related fatalities during the 2016 - 2019 racing seasons.

Retrospective analysis of lameness localisation in Western Performance Horses: A ten-year review.

Training practices, speed and distances undertaken by Thoroughbred racehorses in Victoria, Australia.

Appraising the Welfare of Thoroughbred Racehorses in Training in Queensland, Australia: The Incidence and Type of Musculoskeletal Injuries Vary between Two-Year-Old and Older Thoroughbred Racehorses.

Ontario Racehorse Death Registry, 2003-2015: Descriptive analysis and rates of mortality.

Revisiting predictive biomarkers of musculoskeletal injury in thoroughbred racehorses: longitudinal study in polish population.

Descriptive epidemiology of veterinary events in flat racing Thoroughbreds in Great Britain (2000 to 2013).

An Investigation of Equine Mesenchymal Stem Cell Characteristics from Different Harvest Sites: More Similar Than Not.

Days lost from training by two- and three-year-old Thoroughbred horses: a survey of seven UK training yards.

Mechanical nociceptive thresholds in the axial skeleton of horses.

Factors associated with failure of thoroughbred horses to train and race.

Racehorse injuries, clinical problems and fatalities recorded on British racecourses from flat racing and National Hunt racing during 1996, 1997 and 1998.

Cellular Proliferation of Equine Bone Marrow- and Adipose Tissue-Derived Mesenchymal Stem Cells Decline With Increasing Donor Age.

Retrospective analysis of local injection site adverse reactions associated with 230 allogenic administrations of bone marrow-derived mesenchymal stem cells in 164 horses.

Measuring Volumetric Changes of Equine Distal Limbs: A Pilot Study Examining Jumping Exercise.

Inflammatory response to the administration of mesenchymal stem cells in an equine experimental model: effect of autologous, and single and repeat doses of pooled allogeneic cells in healthy joints.

Stance phase kinematics and kinetics of horses trotting over poles.

Current and Emerging Biologic Therapies for Equine Tendon and Ligament Injuries.

Health of Polo Horses.

Validation of inertial measurement units to detect and predict horse behaviour while stabled.

A Critical Overview of the Use of Platelet-Rich Plasma in Equine Medicine Over the Last Decade.

The Usefulness of Mesenchymal Stem Cells beyond the Musculoskeletal System in Horses.

Development of An Anybody Musculoskeletal Model of The Thoroughbred Forelimb.

Platelet-Rich Products and Their Application to Osteoarthritis.

Equine Manual Therapies in Sport Horse Practice

Practical considerations for clinical use of mesenchymal stem cells: From the laboratory to the horse.

Allogeneic major histocompatibility complex-mismatched equine bone marrow-derived mesenchymal stem cells are targeted for death by cytotoxic anti-major histocompatibility complex antibodies.

Transforming Growth Factor-&#x3b2;2 Downregulates Major Histocompatibility Complex (MHC) I and MHC II Surface Expression on Equine Bone Marrow-Derived Mesenchymal Stem Cells Without Altering Other Phenotypic Cell Surface Markers.

Navigational ultrasound imaging: A novel imaging tool for aiding interventional therapies of equine musculoskeletal injuries.

Extracorporeal Shockwave Therapy for the Horse

Nuclear scintigraphy in horses.

Transforming Growth Factor-β2 Downregulates Major Histocompatibility Complex (MHC) I and MHC II Surface Expression on Equine Bone Marrow-Derived Mesenchymal Stem Cells Without Altering Other Phenotypic Cell Surface Markers.