Injury in horses encompasses a range of physical traumas that can affect various tissues and structures, including bones, muscles, tendons, and ligaments. These injuries can arise from numerous causes, such as accidents, overexertion, or improper handling. Common types of equine injuries include fractures, sprains, strains, and lacerations. The management and treatment of these injuries require an understanding of equine anatomy and biomechanics, as well as appropriate veterinary care. This page collects peer-reviewed research studies and scholarly articles that explore the causes, diagnosis, treatment, and prevention of injuries in horses, providing insights into their impact on equine health and performance.
Lemercier J, Pasco J, Olivier G, Amiot F.Horse riding-related falls are a frequent cause of emergency department (ED) presentations; however, their regional epidemiology in France is poorly described. We aimed to quantify the incidence of ED visits after falling from a horse in the Manche Department and characterize the injury patterns, resource use, and short-term outcomes. Methods: We conducted a multicenter retrospective study across six hospitals in Manche (France), including all patients presenting to the ED after a fall from a horse between May 1, 2021, and October 31, 2024. Demographics, initial clinical status, imaging findin...
Lopez Cruz C, Gonzalez LM, McKinney-Aguirre CA, Hepworth-Warren KL, Roessner HA, Burke M, Fogle CA.To describe the methodology used to identify the contributors to a perceived sudden increase in exploratory celiotomy surgical site infections (SSI) and complications at the North Carolina State University Veterinary Teaching Hospital (NCSU VTH) between 2019 and 2020 and evaluate the effect of the designed intervention up to 4 years after its implementation. Methods: Case-control retrospective study over a five-year period. Methods: A total of 448 horses that underwent exploratory celiotomy for the treatment of acute abdominal pain were included. Methods: Medical records of horses that under...
Taguchi T, Lopez MJ, Aoun R, Helber L.Over the last few decades, cell and cell-based therapies emerged as treatment options for equine tendinopathy and desmopathy. The objective of this study was to critically evaluate outcomes following treatment of equine tendinopathy or desmopathy with adult multipotent stromal/stem cells (MSCs). Unassigned: The PubMed and Web of Science databases were searched for "equine/horse," "tendon/tendinopathy/tendonitis/ligament/ligamentopathy/desmopathy/desmitis," "stem/stromal/mesenchymal/multipotent," and "cell" from January 2001 to June 2025. Studies were identified according to PRISMA guidelines, ...
Loder RT, Walker AL, Blakemore LC.Horse riding is a common sport, but no study specifically addresses joint dislocations. The purpose of this study is to describe joint dislocations due to equines using a national emergency department (ED) database. Such data can be helpful in injury prevention strategies. Unassigned: The National Electronic Injury Surveillance System (NEISS) database for the years 2000-2023 was used. The NEISS database is a statistically representative sample of injuries seen in EDs across the US giving national estimates. Mechanism of injury was tabulated into groups: 1) did the patient fall from the horse 2...
Imai S, Sato R, Fujiwara R, Terui S, Kimura A, Ichijo T, Kasashima Y, Miyazaki T.A 15-year-old Thoroughbred gelding was presented for examination due to chronic corneal opacity in the right eye, which had been noted for several years. An ophthalmic evaluation revealed dense, irregular corneal opacity; an absence of the direct pupillary light reflex; and a positive dazzle reflex. Fluorescein staining was negative and cytology of a corneal conjunctival swab identified nucleated squamous epithelial cells, but no inflammatory cells. Slit-lamp examination failed to visualize intraocular structure, and the lesion was deemed to be chronic and irreversible. An obstacle-avoidance t...
Mazzucco L, Marcatili M, Withers J, Cantatore F.Superficial digital flexor tendinopathy is a common cause of forelimb lameness in Thoroughbred racehorses and sports horses; however, this condition is rarely observed in the hindlimb. A 16-year-old Irish sports horse gelding was presented with bilateral swelling in the plantar metatarsal region and severe bilateral hindlimb lameness visible at the walk. The lameness occurred after the cross-country phase of an eventing competition. The clinical suspicion of superficial digital flexor tendon (SDFT) injury was confirmed after ultrasonographic examination, which revealed an extensive core lesion...
Burns JJ, MacMillan KM.The Standardbred racing industry plays an important role in the North American economy and is expected to continue operating and growing. However, public perception is often unfavorable, with increasing concern about the health and welfare of Standardbred racehorses. Despite this, limited research has examined Standardbred well-being. To address this gap, a survey of equine trainers on Prince Edward Island (PEI) was conducted to evaluate key health and welfare issues during racing careers. Results showed that over one quarter of respondents had at least one horse displaying stereotypic behavio...
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...
Hall NP, Sweeney DM, Holmströem M, Kim W, Wang Y, Donahue KD, Palmer SE, Lambert DH, Bayly WM.To determine whether targeted lesion-specific algorithms developed from data collected with accelerometer-based inertial measurement units worn by racing Thoroughbreds could retrospectively identify horses at high risk of incurring forelimb condylar or proximal sesamoid fractures. Unassigned: Fracture-specific algorithms were generated from July 2021 to December 2024 with accelerometer data from 42,623 races by 15,755 horses, including 54 races by 23 horses that subsequently suffered condylar fractures and 90 races by 31 horses that later sustained proximal sesamoid fractures. Fracture-specifi...
Gerow SL, Clegg SR, Cooke AS.In the UK, fireworks are common during several celebratory events throughout the year. Previous evidence has shown the adverse effects of fireworks on domestic companion animals. However, there has been little focus on equids. An online survey was developed to understand the impact of fireworks on horses and donkeys, how owners attempt to mitigate these impacts, and the owners' views on fireworks. A total of 1,234 horse owners and 232 donkey owners responded. The majority (77%) advocated tighter regulations surrounding the use of fireworks, including reduction in the maximum noise produced, an...
Copelin C, Merkies K.Equestrian sport's social license to operate has come under scrutiny due to concerns surrounding the well-being of ridden horses. Inappropriate equipment use, such as harsh bits or overtight nosebands, can negatively influence well-being by generating inescapable pressure or pain on the sensitive structures of the horse's head and limiting natural behaviours. Restrictive equipment may also be used to generate exaggerated, stressful and uncomfortable head and neck positions such as hyperflexion. Saddles must be properly fitted to both horse and rider to ensure appropriate distribution of kinema...
Dos Santos TS, Dillmann JB, Giovelli M, Elias GO, Lima RK, Cescon S, Stainki DR, Dos Santos RC, Corrêa C, Monteiro SG.This study reports the successful use of maggot therapy in four horses with traumatic wounds caused by wire fences, treated in veterinary clinics and under field conditions in southern Brazil. All lesions showed tissue necrosis, purulent discharge, and foul odor, indicating infection and delayed healing. Sterile Lucilia cuprina larvae (L1 stage) were applied directly to the wounds for 48 hours. Rapid improvement was observed, with marked reduction of necrotic tissue, exudate, and odor, and stimulation of granulation tissue in three cases. Complete wound closure occurred between 10 and 60 days ...
Choi Y, Rosanowski SM, Parkin TD.To identify risk factors associated with complete humerus fractures in Thoroughbreds in South Korea. Unassigned: A retrospective case-control design with multivariable logistic regression was used. This study included 131 Thoroughbreds diagnosed with complete humerus fractures following racetrack activity between 2009 and 2022 (inclusive). Additionally, 660 healthy Thoroughbreds (699 observations) with at least 1 racetrack activity during the same period were included as controls. Unassigned: A total of 8 variables were associated with the risk of complete humerus fractures. Notably, horses wi...
de Chaisemartin C, Belluco S, Nottrott K.Dental masses such as odontogenic masses, heterotopic polydontia, or ectopic supernumerary teeth have been documented in the equine head. This is the first case report of a large maxillary sinus mass with 3 ectopic teeth in an adult horse. A 14-year-old warmblood gelding was presented for evaluation of chronic right-sided nasal discharge. After imaging exploration, surgery was performed on the standing horse with a conchofrontal sinus trephination and a large maxillary bone (MB) sinusotomy. The examinations revealed a sinusal mass in the right maxillary sinus covered by sinusal mucosa and surr...
Goetz M, Cremoux M, Lassalle L, Douet JY.To assess the efficacy and safety of Rose Bengal and green light corneal cross-linking (RGX) as an adjunctive treatment for complicated corneal ulcers and stromal abscesses in horses. Methods: A retrospective analysis included 81 horses (82 eyes) treated with RGX between 2018 and 2024. Cases involved complicated corneal diseases such as melting keratitis, fungal keratitis, deep stromal defects, and stromal abscesses. Treatment consisted of topical or iontophoretic administration of 1% Rose Bengal followed by green light irradiation (550 nm; 150 J/cm) for 10 min. Most procedures (76.8%) w...
Puccetti M, Beccati F, Pilati N.Femoral nerve neuropathy causes lameness, a condition clinically characterized by stifle's lack of extension with subsequent diminished lower limb function. This case report describes the ultrasonographic diagnosis of femoral neuropathy secondary to compression caused by myopathy of the iliopsoas muscle of an endurance horse during a competition. Transrectal ultrasonography played a pivotal role in diagnosis of the injury by assessment of the involved structures and monitoring of the healing process throughout the recovery period. The horse achieved complete recovery and successfully returned ...
Pécresse B, Moiroud C, Hanne-Poujade S, Hatrisse C, De Azevedo E, Coudry V, Jacquet S, Audigié F, Chateau H.Locomotor disorders involving the spine are a major cause of impaired performance and early retirement in sport horses. Swimming is increasingly incorporated into rehabilitation protocols, but its effects on spinal biomechanics remain poorly understood. This prospective study evaluated changes in thoracolumbar mobility in sixteen sport horses diagnosed with cervical or thoracolumbar axial musculoskeletal lesions over a 12-week rehabilitation program comprising 4 weeks of land-based training followed by 8 weeks during which swimming sessions were incorporated three times per week. Weekly measur...
White K, Hird J, Taylor P.The recovery period is associated with the greatest risk of injury for horses undergoing anaesthesia. Recovery quality and duration can be influenced by the volatile agent. Methods: This prospective, randomised blinded clinical investigation recruited 101 healthy client-owned horses undergoing elective surgery at one UK equine hospital. Anaesthesia was standardised, and horses were randomly assigned to receive desflurane or isoflurane for maintenance. Horses were ventilated to normocapnia and received dobutamine to maintain mean arterial blood pressure above 60 mmHg. All the patients received ...
Repciuc CC, Oros NV, Mureșan ȘMC, Sevastre B, Joaquim JGF, Oana LI.Limb wounds in horses represent a significant therapeutic challenge due to poor vascularization, reduced skin elasticity, and high risk of complications such as exuberant granulation tissue. Conventional treatments sometimes fail to provide satisfactory healing outcomes, leading to prolonged recovery and increased costs. This study aimed to evaluate the efficacy of topical ozone therapy using the bagging method in promoting the epithelialization and contraction of chronic distal limb wounds in horses refractory to conventional management. Eight horses, aged 3-21 years, with chronic wounds aver...
Qiu Z, Wang J, Zhang Y, Liu X, Wei C, Ma T.Musculoskeletal injuries represent a primary cause of suboptimal performance and early retirement in equine athletes. To address this challenge, the veterinary community has long endeavored to develop safer and more effective therapeutic strategies. Extracorporeal shock wave therapy (ESWT), as a treatment for equine musculoskeletal injuries, has garnered substantial attention among equine veterinarians. Focused on the theme ESWT Therapy for Equine Musculoskeletal Disorders: From biological mechanisms to clinical applications, this article systematically reviews existing literature on the biolo...
Tobin G, Cullen S, Dunne A, Warrington G, Pugh J, McGoldrick A, Nolan C, Losty C.Stable staff and trainers are essential to racing yards and horse welfare, yet limited research focuses on this vital workforce that the thoroughbred industry heavily relies on. This systematic narrative review synthesizes existing literature on the occupational health and well-being of stable staff and trainers in the thoroughbred horse racing industry. Methods: A systematic narrative review was conducted across PubMed, Google Scholar, and Scopus using relevant keywords. Manuscripts reporting occupational or mental health data on stable staff and/or trainers and had the full-text available we...
van den Broek M, Chan ZYS, De Bruyne C, Garcia-Alamo K, Skotarek Loch S, Pfau T.Increased risk of musculoskeletal injury in galloping racehorses has been linked to decreased stride length and reduced speed over consecutive races prior to the injury. As racetrack curvature influences horses' maximal speed, we hypothesized it also affects stride parameters. During training sessions, twenty-eight wagon-pulling Thoroughbred Chuckwagon horses were equipped with Global Navigation Satellite System (GNSS) loggers, allowing for identification of speed, stride length (SL) and stride frequency (SF), and average speed, SL and SF were calculated for consecutive 100 m sections. Effects...
Honnas DH, Fiske-Jackson AR, Fulkerson CV, Wilhite DR.An injury of a tendon or ligament of the equine foot is frequently a cause of lameness. The optimal radiographic projections delineating the entheses of five commonly injured tendons and ligaments of the foot should be described. Methods: The entheses of the collateral ligaments of the distal interphalangeal joint, the collateral sesamoidean ligaments of the navicular bone, the deep digital flexor tendon, the common digital extensor tendon and the distal sesamoidean impar ligament were isolated from a thoracic foot of three cadavers. Three standard radiographic projections (60-degree, dorsopro...
Stäubli T, Theiss F, Bischofberger A.A total of 48 horses with unilateral (n = 44) or bilateral (n = 4) overstrain-induced complete rupture of the superficial digital flexor tendon (SDFT) in the forelimbs were retrospectively analysed. A telephone questionnaire, carried out an average of 5,9 years post-injury, served as a long-term follow-up in 25 horses. The mortality rate associated with SDF tendonitis was 12,0 % (3/25). Superficial digital flexor tendonitis did not recur in 76,0 % (19/25) of the horses, but at least one subsequent episode occurred in 24,0 % (6/25). The results of this study indicate that it is reasonable...
De Zani D, Rabbogliatti V, Rabba S, Auletta L, Longo M, Zani DD.Damage to the osteochondral unit is a common cause of lameness in horses. Published descriptions of MRI findings of osteochondral unit and subchondral damage are currently lacking, and only a few reports describe outcomes in sport horses. The aims of this case series retrospective study were to describe different MRI patterns of osteochondral/subchondral pathology in the fetlock joint using low-field MRI and to provide outcome information. A total of 35 sport horses were included. Data regarding detailed clinical history, treatment and outcome were evaluated. MRI identified a total of 39 bone ...
McDonald S, Verheyen KLP, Chang YM, Allen SE.Race-related injuries in horse racing, especially those requiring extended recovery, are a welfare concern and threaten the sport's social licence. Previous studies predominantly report on fatalities; however, serious non-fatal musculoskeletal injuries often end horses' racing careers or have a high recurrence risk. No recent studies have described or quantified long-term injuries (LTIs) in racing Thoroughbreds, which is essential to inform targeted risk prevention strategies. Objective: To describe the types, frequencies and incidences of LTIs in British jump racing. Methods: Retrospective co...
Gunsmaa G, Gurbazar U, Badarch TU, Ichikawa M.The aim of this study was to assess the effectiveness of safety regulations governing traditional Mongolian horse racing on the frequency and severity of injuries among child jockeys. Regulations introduced in 2019 mandate the wearing of helmets and protective clothing, prohibit the participation of jockeys aged < 7 years, and ban horse racing during the cold season (November-April). National injury surveillance data were used to compare the profile of injuries that occurred among children aged < 15 years in the 4-year periods before and after the introduction of the regulations (2015-2018 ...
Pilger F, Aurich C, Aurich JE.The early career start of racehorses, the pretraining of two-year-old Warmblood stallions for licensing, and individual housing of young horses increasingly raise animal welfare concerns. Objective: Assess pretraining practices and the opinion of trainers on housing of young horses, minimum age to commence training and pretraining injuries. Methods: Qualitative interviews with trainers of Warmblood stallions and Thoroughbred and Trotter racehorses (n = 10 each). Results: Pretraining of Thoroughbreds and Trotters began at 18 months, whereas licensing preparation of Warmblood stallions began at ...
Ken-Dror G, Chua V, Sharma P.To determine the frequency of traumatic injuries in polo players in England. Methods: The survey included data on body location and reason for injury derived from accident reports using a retrospective cohort design from 26 participating English polo clubs between the years 2018 and 2024. Results: The study population included injuries in 236 polo players. The most common injury site was the limb (arm, hand, leg, wrist, shoulder) 47.9% (95% CI: 41.4-54.5), and face or head 38.6% (95% CI: 32.3-45.1), of which 12.1% (95% CI: 6.2-20.6) affected the eyes. The most common reason to require hospital...
Norrlund RR, Caragounis EC, Olsén MF.Equestrian sports have been found to cause high rates of injuries. In clinical practise after such injuries, polytrauma protocol workups usually include whole-body computed tomography (WBCT), CT of the chest, abdomen and pelvis with intravenous iodine contrast medium, and CT of the cervical spine and brain without contrast. The purpose was to investigate the use of WBCT in equestrian-related accidents, to analyse demographics, mechanism of injury (MOI), therapy and severity of equine-related accidents, radiology, and the use of protecting equipment. Methods: This is a retrospective study inclu...
Godwin EE, Young NJ, Dudhia J, Beamish IC, Smith RK.Mesenchymal stem (progenitor; stromal) cell (MSC) therapy has gained popularity for the treatment of equine tendon injuries but without reports of long-term follow-up. Objective: To evaluate the safety and reinjury rate of racehorses after intralesional MSC injection in a large study of naturally occurring superficial digital flexor tendinopathy and to compare these data with those published for other treatments. Methods: Safety was assessed clinically, ultrasonographically, scintigraphically and histologically in a cohort of treated cases: 141 client-owned treated racehorses followed-up for a...
Smith RK, Werling NJ, Dakin SG, Alam R, Goodship AE, Dudhia J.Tendon injuries are a common age-related degenerative condition where current treatment strategies fail to restore functionality and normal quality of life. This disease also occurs naturally in horses, with many similarities to human tendinopathy making it an ideal large animal model for human disease. Regenerative approaches are increasingly used to improve outcome involving mesenchymal stem cells (MSCs), supported by clinical data where injection of autologous bone marrow derived MSCs (BM-MSCs) suspended in marrow supernatant into injured tendons has halved the re-injury rate in racehorses....
Schnabel LV, Lynch ME, van der Meulen MC, Yeager AE, Kornatowski MA, Nixon AJ.Tendinitis remains a catastrophic injury among athletes. Mesenchymal stem cells (MSCs) have recently been investigated for use in the treatment of tendinitis. Previous work has demonstrated the value of insulin-like growth factor-I (IGF-I) to stimulate cellular proliferation and tendon fiber deposition in the core lesion of tendinitis. This study examined the effects of MSCs, as well as IGF-I gene-enhanced MSCs (AdIGF-MSCs) on tendon healing in vivo. Collagenase-induced bilateral tendinitis lesions were created in equine flexor digitorum superficialis tendons (SDFT). Tendons were treated with ...
Thorpe CT, Streeter I, Pinchbeck GL, Goodship AE, Clegg PD, Birch HL.Little is known about the rate at which protein turnover occurs in living tendon and whether the rate differs between tendons with different physiological roles. In this study, we have quantified the racemization of aspartic acid to calculate the age of the collagenous and non-collagenous components of the high strain injury-prone superficial digital flexor tendon (SDFT) and low strain rarely injured common digital extensor tendon (CDET) in a group of horses with a wide age range. In addition, the turnover of collagen was assessed indirectly by measuring the levels of collagen degradation mark...
Lomas AJ, Ryan CN, Sorushanova A, Shologu N, Sideri AI, Tsioli V, Fthenakis GC, Tzora A, Skoufos I, Quinlan LR, O'Laighin G, Mullen AM, Kelly JL....Tendon injuries represent a significant clinical burden on healthcare systems worldwide. As the human population ages and the life expectancy increases, tendon injuries will become more prevalent, especially among young individuals with long life ahead of them. Advancements in engineering, chemistry and biology have made available an array of three-dimensional scaffold-based intervention strategies, natural or synthetic in origin. Further, functionalisation strategies, based on biophysical, biochemical and biological cues, offer control over cellular functions; localisation and sustained relea...
Nixon AJ, Dahlgren LA, Haupt JL, Yeager AE, Ward DL.To assess the potential of adipose-derived nucleated cell (ADNC) fractions to improve tendon repair in horses with collagenase-induced tendinitis. Methods: 8 horses. Methods: Collagenase was used to induce tendinitis in the superficial digital flexor tendon of 1 forelimb in each horse. Four horses were treated by injection of autogenous ADNC fractions, and 4 control horses were injected with PBS solution. Healing was compared by weekly ultrasonographic evaluation. Horses were euthanatized at 6 weeks. Gross and histologic evaluation of tendon structure, fiber alignment, and collagen typing were...
Bosch G, van Schie HT, de Groot MW, Cadby JA, van de Lest CH, Barneveld A, van Weeren PR.Tendon injuries are notorious for their slow and functionally inferior healing. Intratendinous application of platelet-rich plasma (PRP) has been reported to stimulate the repair process of tendon injuries, but there is little conclusive evidence for its effectiveness. A placebo-controlled experimental trial was performed to test the hypothesis that a single intratendinous PRP treatment enhances the quality of tendon repair, as evidenced by improved biochemical, biomechanical, and histological tissue properties. In six horses, tendon lesions were created surgically in the Superficial Digital F...
Ferris DJ, Frisbie DD, Kisiday JD, McIlwraith CW, Hague BA, Major MD, Schneider RK, Zubrod CJ, Kawcak CE, Goodrich LR.To report outcome of horses with femorotibial lesions (meniscal, cartilage or ligamentous) treated with surgery and intra-articular administration of autologous bone marrow derived mesenchymal stem cells (BMSCs). Methods: Prospective case series. Methods: Horses (n = 33). Methods: Inclusion criteria included horses that had lameness localized to the stifle by diagnostic anesthesia, exploratory stifle arthroscopy and subsequent intra-articular administration of autologous BMSCs. Case details and follow-up were gathered from medical records, owner, trainer or veterinarian. Outcome was defined as...
Thorpe CT, Clegg PD, Birch HL.Tendon injury is one of the most common causes of wastage in the performance horse; the majority of tendon injuries occur to the superficial digital flexor tendon (SDFT) whereas few occur to the common digital extensor tendon. This review outlines the epidemiology and aetiology of equine tendon injury, reviews the different functions of the tendons in the equine forelimb and suggests possible reasons for the high rate of failure of the SDFT. An understanding of the mechanisms leading to matrix degeneration and subsequent tendon gross failure is the key to developing appropriate treatment and p...
Dakin SG, Dudhia J, Smith RK.Injuries to the superficial digital flexor tendon (SDFT) are an important cause of morbidity and mortality in equine athletes, but the healing response is poorly understood. One important drive for the healing of connective tissues is the inflammatory cascade, but the role of inflammation in tendinopathy has been contentious in the literature. This article reviews the processes involved in the healing of tendon injuries in natural disease and experimental models. The importance of inflammatory processes known to be active in tendon disease is discussed with particular focus on recent findings ...
Thorpe CT, Udeze CP, Birch HL, Clegg PD, Screen HR.Age-related tendinopathy is common in both humans and horses; the initiation and progression of which is similar between species. The majority of tendon injuries occur to high-strain energy storing tendons, such as the human Achilles tendon and equine superficial digital flexor (SDFT). By contrast, the low-strain positional human anterior tibialis tendon and equine common digital extensor (CDET) are rarely injured. It has previously been established that greater extension occurs at the fascicular interface in the SDFT than in the CDET; this may facilitate the large strains experienced during l...
Dyson SJ.There is a lack of long-term follow-up data for outcome of medical treatment of superficial digital flexor (SDF) tendonitis. Objective: To determine whether intralesional injection of hyaluronan, beta aminoproprionitrile fumarate (BAPN) or polysulphated glycosaminoglycans (PSGAG) or systemic administration of PSGAG yielded better results than a controlled exercise programme alone in the management of SDF tendonitis, with a minimum follow-up period of 2 years after resumption of full work; and to determine whether reinjury rate was related to sports discipline and whether fibre alignment score ...
Sivaguru M, Durgam S, Ambekar R, Luedtke D, Fried G, Stewart A, Toussaint KC.Fourier transform-second harmonic generation (FT-SHG) imaging is used as a technique for evaluating collagenase-induced injury in horse tendons. The differences in collagen fiber organization between normal and injured tendon are quantified. Results indicate that the organization of collagen fibers is regularly oriented in normal tendons and randomly organized in injured tendons. This is further supported through the use of additional metrics, in particular, the number of dark (no/minimal signal) and isotropic (no preferred fiber orientation) regions in the images, and the ratio of forward-to-...
Thorpe CT, Godinho MSC, Riley GP, Birch HL, Clegg PD, Screen HRC.While the predominant function of all tendons is to transfer force from muscle to bone and position the limbs, some tendons additionally function as energy stores, reducing the cost of locomotion. Energy storing tendons experience extremely high strains and need to be able to recoil efficiently for maximum energy storage and return. In the equine forelimb, the energy storing superficial digital flexor tendon (SDFT) has much higher failure strains than the positional common digital extensor tendon (CDET). However, we have previously shown that this is not due to differences in the properties of...
Eddy AL, Van Hoogmoed LM, Snyder JR.Equine thermography has increased in popularity recently because of improvements in thermal cameras and advances in image-processing software. The basic principle of thermography involves the transformation of surface heat from an object into a pictorial representation. The colour gradients generated reflect differences in the emitted heat. Variations from normal can be used to detect lameness or regions of inflammation in horses. Units can be so sensitive that flexor tendon injuries can be detected before the horse develops clinical lameness. Thermography has been used to evaluate several dif...
Kasashima Y, Takahashi T, Smith RK, Goodship AE, Kuwano A, Ueno T, Hirano S.Overstrain injuries to the superficial digital flexor tendon (SDFT) and suspensory ligament (SI) are among the most common musculoskeletal injuries which contribute to the considerable wastage of racing Thoroughbreds. Many epidemiological studies have demonstrated the prevalence of and risk factors for tendon injury when racing but have not included those injuries sustained during training. However, since tendon injury during training is seen commonly in clinical practice, it is appropriate to determine the overall prevalence of tendon injury sustained during both training and racing. Objectiv...
Patterson-Kane JC, Becker DL, Rich T.The equine superficial digital flexor tendon (SDFT) is a frequently injured structure that is functionally and clinically equivalent to the human Achilles tendon (AT). Both act as critical energy-storage systems during high-speed locomotion and can accumulate exercise- and age-related microdamage that predisposes to rupture during normal activity. Significant advances in understanding of the biology and pathology of exercise-induced tendon injury have occurred through comparative studies of equine digital tendons with varying functions and injury susceptibilities. Due to the limitations of in-...
Dowling BA, Dart AJ, Hodgson DR, Smith RK.The superficial digital flexor tendon (SDFT) is an elastic structure that during maximal exercise appears to operate close to its functional limits. The biomechanical and biochemical responses to exercise, injury, and healing are still poorly understood but ongoing research is providing valuable new information which is addressed in this review. It appears that the SDFT matures early, after which time it has limited ability to adapt to stress and undergoes progressive degeneration. Focal hypocellularity, collagen fibril degeneration, selective fibril loading and alterations in the noncollageno...
Smith RK.Optimal management of tendon overuse injuries in equine and human athletes should avoid the formation of excessive scar tissue, regenerate normal tendon matrix, and reduce re-injury rates. We hypothesized that the implantation of marrow-derived stromal stem cells (BM-MSCs), in far greater numbers than are present normally within tendon tissue, would synthesize a matrix more closely resembling tendon matrix than scar tissue, and hence increase the capacity to return to performance successfully. This article reviews the technique used clinically in the horse and the current outcome data for hors...
Guest DJ, Smith MR, Allen WR.Injury to the superficial digital flexor tendon (SDFT) is common in racing and sport horses and poor tendon regeneration leads to high reinjury rates. Autologous mesenchymal stromal cells (MSCs) are being used clinically to improve tendon regeneration but they have some practical limitations. Embryonic stem cells (ESCs) may overcome these limitations but their fate following injection into the damaged SDFT is unknown. Objective: To inject MSCs and ESCs into distinct areas of damage in the SDFT and monitor their survival over a 3 month period. Methods: MSCs and ESCs expressing different reporte...
Rossdale PD, Hopes R, Digby NJ, offord K.An epidemiological study of wastage among racehorses was conducted in 1982 and 1983 among six stables, five of which were in Newmarket. The basis of the survey was the inability of horses to take part in cantering exercise as a result of injury or disease. The greatest number of days lost to training was caused by lameness (67.6 per cent) and respiratory problems (20.5 per cent). Conditions of the foot (19 pe cent), muscle (18 per cent), carpus (14 per cent), fetlock joints (14 per cent), tendons (10 per cent) and sore shins (9 per cent) were the major reasons for training days being lost in 1...
Murray RC, Walters JM, Snart H, Dyson SJ, Parkin TD.The aim of this study was to describe the prevalence of illness and lameness at different anatomical sites in registered United Kingdom dressage horses and to identify risk factors for lameness. A questionnaire was sent to all 11,363 registered members of British Dressage in 2005, with one questionnaire assigned per horse. Four multivariable logistic regression models were developed for each section of the questionnaire. A final mixed effects logistic regression model was developed which combined the results from all prior models. Owners reported that 33% of horses had been lame at some time d...
Smith RK, Birch HL, Goodman S, Heinegård D, Goodship AE.Strain-induced tendinopathy is a common injury in both human and equine athletes, with increasing incidence associated with greater involvement in sport and an increasingly aged population. This paper reviews our studies on the abundant non-collagenous protein, cartilage oligomeric matrix protein (COMP), in equine tendons. Its variation between tendon type and site, age and exercise has provided an insight into how age and exercise influence tendon growth and maturation. Tendons can be broadly divided into two types, reflecting their different matrix composition and function: the energy-storin...
Peffers MJ, Thorpe CT, Collins JA, Eong R, Wei TK, Screen HR, Clegg PD.Energy storing tendons, such as the human Achilles and equine superficial digital flexor tendon (SDFT), are highly prone to injury, the incidence of which increases with aging. The cellular and molecular mechanisms that result in increased injury in aged tendons are not well established but are thought to result in altered matrix turnover. However, little attempt has been made to fully characterize the tendon proteome nor determine how the abundance of specific tendon proteins changes with aging and/or injury. The aim of this study was, therefore, to assess the protein profile of normal SDFTs ...
Carvalho Ade M, Badial PR, Álvarez LE, Yamada AL, Borges AS, Deffune E, Hussni CA, Garcia Alves AL.Tendon injury is a major cause of lameness and decreased performance in athletic equines. Various therapies for tendonitis have been described; however, none of these therapies results in complete tissue regeneration, and the injury recurrence rate is high even after long recovery periods involving rest and physiotherapy. Methods: A lesion was induced with collagenase gel in the superficial digital flexor tendon in the center portion of the metacarpal region of eight equines of mixed breed. After two weeks, the lesions of the animals in the treated and control groups were treated through the i...
Thorpe CT, Klemt C, Riley GP, Birch HL, Clegg PD, Screen HR.The predominant function of tendons is to position the limb during locomotion. Specific tendons also act as energy stores. Energy-storing (ES) tendons are prone to injury, the incidence of which increases with age. This is likely related to their function; ES tendons are exposed to higher strains and require a greater ability to recoil than positional tendons. The specialized properties of ES tendons are thought to be achieved through structural and compositional differences. However, little is known about structure-function relationships in tendons. This study uses fascicles from the equine s...
Richardson LE, Dudhia J, Clegg PD, Smith R.Stem cells have evoked considerable excitement in the animal-owning public because of the promise that stem cell technology could deliver tissue regeneration for injuries for which natural repair mechanisms do not deliver functional recovery and for which current therapeutic strategies have minimal effectiveness. This review focuses on the current use of stem cells within veterinary medicine, whose practitioners have used mesenchymal stem cells (MSCs), recovered from either bone marrow or adipose tissue, in clinical cases primarily to treat strain-induced tendon injury in the horse. The backgr...
Hitchens PL, Morrice-West AV, Stevenson MA, Whitton RC.Studies of racehorse injury or fatality in various countries have identified common, and in some cases conflicting, risk factors. We conducted a systematic search of the relevant literature published from 1990 to 2017. Peer-reviewed articles were included if they reported the incidence of fatal or catastrophic musculoskeletal injury (CMI) in Thoroughbred flat races (n=21) or risk factors for CMI (n=65). Pooled effect sizes were estimated using the random-effects DerSimonian-Laird model. The pooled incidence of CMI was 1.17 (95% confidence interval 0.90, 1.44) per 1000 race starts. Almost 300 f...
Ball CG, Ball JE, Kirkpatrick AW, Mulloy RH.Horseback riding is more dangerous than motorcycle riding, skiing, football, and rugby. The purpose of this study was to identify the incidence and injury patterns, as well as risk factors associated with severe equestrian trauma. Methods: All patients with major equestrian injuries (injury severity score > or = 12) admitted between 1995 and 2005 were reviewed. A 46-question survey outlining potential rider, animal, and environmental risk factors was administered. Results: Among 7941 trauma patients, 151 (2%) were injured on horseback (mean injury severity score, 20; mortality rate, 7%). In...
Bosch G, Moleman M, Barneveld A, van Weeren PR, van Schie HT.The repair process of tendon injuries, which are common in both human and equine athletes, is slow and the quality of the repair tissue is often inferior to the original tendon tissue, which frequently leads to re-injury. The relatively poor vascularization of tendons is considered to be one of the reasons for their limited healing potential. Recently, platelet-rich plasma (PRP), an autologous concentrate of platelets, rich in growth factors, has been shown to enhance the repair process of injured tendons. This effect has been ascribed to the high levels of growth factors in PRP, several of wh...
