Horse breeds represent the diverse genetic and phenotypic variations found within the species Equus ferus caballus. These breeds are categorized based on characteristics such as size, conformation, coat color, and temperament, which have been selectively bred over centuries to fulfill specific roles and functions. Common classifications of horse breeds include light horses, draft horses, and ponies, each serving different purposes ranging from riding and racing to work and companionship. This page aggregates peer-reviewed research studies and scholarly articles that explore the genetics, history, and functional attributes of various horse breeds, as well as their impact on equine management and breeding practices.
Rykala M, Jasiak M, Niedzwiedz A.Preventing the spread of infectious diseases in horses requires breaking the chain of infection through appropriate prophylaxis. In Poland, where the horse population reached 273,006 in 2023, vaccinations are voluntary and primarily the responsibility of horse owners, with mandatory influenza vaccinations limited to sport horses. This study aimed to evaluate the vaccination status of Polish horses against infectious diseases through a survey of 980 horse owners and an analysis of 123 horse passports from slaughterhouses. Survey participants represented all provinces, predominantly owning warmb...
Sigurðardóttir H, Eriksson S, Niazi A, Rhodin M, Albertsdóttir E, Kristjansson T, Lindgren G.Selection for performance in horse breeding benefits from precise genetic insights at a molecular level, but knowledge remains limited. This study used whole-genome sequences of 39 elite and non-elite Icelandic horses to identify candidate causal variants linked to previously identified haplotypes in the STAU2 and RELN genes affecting pace and other gaits. A frameshift variant in linkage disequilibrium with the previously identified haplotypes in the STAU2 gene (r2 = 0.85) was identified within a predicted STAU2 transcript. This variant alters the amino acid sequence and introduces a prema...
Obradovic NA, McFadden A, Martin K, Vierra M, McLoone K, Martin E, Thomas A, Everts RE, Brooks SA, Lafayette C.This paper reports three novel KIT variants likely responsible for previously unexplained white patterning phenotypes observed in three groups of horses. White spots and markings may have substantial consequences on the value and health of domesticated horses. This study aims to elucidate the genetic mechanisms underlying depigmented coat colors to aid in producing prosperous herds. Aligned whole genome sequences were manually screened to identify three polymorphisms in a family of Anglo-Arabian horses (N = 7), a family of Warmblood horses (N = 5), and a single stock-type mare with unexplained...
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...
Martinez-Saez L, Marín-García PJ, Llobat ML.Osteochondrosis (OC) is a frequent manifestation of developmental orthopaedic disease, and its severe clinical presentation is known as OC dissecans (OCD). OC is defined as a disruption of the endochondral ossification process in the epiphyseal cartilage, and this disease has been reported in different mammalian species, including humans, dogs, pigs, and horses. OCD is an important cause of lameness in sport horses and is a common cause of impaired orthopaedic potential, whose clinical signs may be of minimal magnitude or manifest as severe joint effusion or clinically noticeable lameness. The...
Cantatore F, Marcatili M, Giacchi A, Stephenson R, Withers J.Morel-Lavallée lesions (MLLs) are post-traumatic, closed, degloving injuries observed in humans and cats. Morel-Lavallée lesions have never been reported in horses. An 8-year-old Warmblood gelding used for dressage presented with a large swelling on the craniomedial aspect of the stifle that did not respond to conservative treatment. Ultrasonography revealed a large anechogenic fluid-filled cavity with a well-defined capsule. Standing endoscopic examination revealed separation between the deep crural fascia, vastus medialis muscle and skin. Cytology of the fluid collected demonstrated a lymp...
Asti V, Summer A, Ablondi M, Sartori C, Giontella A, Pilastro V, Mecocci S, Cappelli K, Mancin E, Oian A, Mantovani R, Capomaccio S, Sabbioni A.Horses have undergone extensive natural and artificial selection, shaping the diversity of breeds observed today. Native Italian breeds present unique traits influenced by natural selection, such as adaptation to harsh climates, or hoof strength, but face challenges due to population declines and the reduction of their original breeding purpose. This study focuses on five local Italian breeds: Bardigiano, Haflinger, Maremmano, Murgese, and Italian Heavy Draught Horse, to understand how selection has shaped their populations. A total of 1620 individuals were genotyped with a medium-density SNP ...
Ding W, Gong W, Bou T, Shi L, Lin Y, Shi X, Li Z, Wu H, Dugarjaviin M, Bai D.Copy number variation (CNV) is an important source of genetic variation. However, studies utilizing whole-genome sequencing to investigate CNVs in horse populations and their effects on traits remain relatively limited. This study aims to address the lack of research on the impact of copy number variation (CNV) on racing performance in horse populations, providing new insights for locally bred racing breeds. We analyzed 60 offspring derived from the crossbreeding of Thoroughbred horses and Xilingol horses. These horses were temporarily named "Grassland-Thoroughbred" and were divided into two g...
Ziadi C, Valera M, Laseca N, Perdomo-González D, Demyda-Peyrás S, de Los Terreros AR, Molina A. By simultaneously integrating both genotyped and non-genotyped animals into genetic evaluation, the single-step genomic BLUP method enhanced the accuracy of genetic assessments. This study aimed to compare the increase in prediction reliability (R) between restricted maximum likelihood (REML) and single-step genomic REML (ssGREML) in the Pura Raza Española (PRE) horse breed. The dataset comprised reproductive records for seven fertility traits from 47,502 females, with a total of 57,316 animals represented in the pedigree. A total of 4009 animals were genotyped using the EQUIGENE 90K SNP ar...
Cravana C, Medica P, Fazio E, Satué K, Brancato G, La Fauci D, Bruschetta G.The hypothalamic-pituitary-adrenal (HPA) axis is a neuroendocrine system involved in the coping response to stressful challenges during exercise stimuli. Exercise represents a significant disruptor of homeostasis, inducing an ACTH-cortisol co-secretion, based on different characteristics of exercise in sport horses. Based on this statement, the aim of this study is to evaluate the circulating adrenocorticotropin and cortisol changes in Standardbred trotters, after training and racing sessions, considering the different age and sex. In particular, the aim is to determine to what extent the leve...
Parra MT, Ayala MSF.A retrospective study was conducted at the Foal Care Equine Perinatology Center in Colombia from October 2017 to May 2023. The goal was to analyze the most frequent pathologies, as well as assess the sexes, ages, and breeds of the patients, with an emphasis on the perinatal population. Out of 945 clinical histories, 776 pertained to perinatology. Survival rates were calculated, and a descriptive analysis was performed. The overall survival rate for neonates was 73.6%, with females constituting 57% of the neonatal patients. The most prevalent breed among mares and neonates was the Creole Colomb...
Coelho C, Vintem C, Silva AS, Santos C, Santos AM, Leite A, Souza V, Siqueira R, Filho HCM, Simões J.The present work aimed to evaluate the influence of a training programme on energy expenditure (EE), cost of transport (COT, cardiac beats to move the body mass during exercise) and metabolic power (Pmet) in young Purebred Lusitano horses used in dressage. With this purpose, nine male horses, ~4 years old, were evaluated before (M1) and after 6 weeks (M2) of a training programme that included 40-80 min of preparatory dressage exercises, 6×/week, individually adjusted. In M1 and M2, the animals were examined in a dressage field test (DFT), when heart rate (HR) and respiratory rate (RR), body...
Walz KR, McCormick ME, Fedorka CE.Breed bias exists within many of the top disciplines of equestrian sport. Therefore, the objective of this study was to evaluate the influence of breed on performance at the CCI5*-L level of eventing. To do so, the results of all CCI5*-L events from 2014 to 2024 were assessed. Initially, Thoroughbreds were compared to all non-Thoroughbreds, and this was followed by assessing the ten primary breeds. Data included penalties accrued in dressage, cross country, show jumping, and overall. Additionally, the likelihood of completing each phase was assessed. It was found that Thoroughbreds accrued mor...
Main SC, Ivey JLZ, Strickland LG, Rhinehart JD, Sun X.Land-Grant Institutions and Cooperative Extension Services seek to disseminate information to the public; however, Extension agents differ in areas of expertise, leaving some counties with minimal ability to provide 4-H horse project members with sufficient content knowledge while agents in other counties are more well versed in equine-specific areas. Results from the 2021 and 2023 Tennessee regional and 2022 Eastern National 4-H Hippology contests were used to determine areas of knowledge deficiency. Nutrition, tack, selection, health, and breeds were categories identified as areas in which 4...
Share ER, Mastellar SL, Rumble JN, Eastridge ML.Equine industry housing and feeding management strategies vary widely. Management choices are important as horses spend most of their time in housing environments and demonstrating ingestive/foraging behavior. As of 2023, over 1.4 million Ohioans identified as horse owners and/or enthusiasts. The objectives of this survey were to determine demographics of the Ohio horse industry, commonly used sources of information, knowledge gaps regarding equine management practices, and to explore what may influence equine management choices. Using Qualtrics (Provo, UT), a 52-question online, anonymous sur...
Gelinder Viklund Å, Blom Y, Eriksson S.The breeding goal of the Swedish Warmblood horse (SWB) is to produce internationally competitive horses in dressage and show jumping. In the current genetic evaluation, breeding values are estimated in multiple-trait animal models where competition performance is the target trait and results from two different young horse tests serve as indicator traits. However, preselection of horses, both for young horse tests and for competitions, is not considered in the current evaluation. The overall aim of this study was to analyse the all-or-none trait start status, in competition and in young horse t...
Knox AL, Fenner K, Zsoldos RR, Wilson B, McGreevy P.The off-the-track Thoroughbred's (OTTTB's) suitability for equestrian retraining and rehoming should always be subject to behavioral considerations. Certain attributes may be advantageous to a horse's racing performance but unfavorable to their prospects off the track. It is important to gain a non-biased understanding of how Thoroughbreds (TBs) in equestrian disciplines compare with other horses behaviorally, to minimize risks of poor welfare and safety outcomes. The current study used owner-reported information ( = 1633) from the Equine Behavior Assessment and Research Questionnaire (E-BARQ)...
Ding W, Gong W, Bou T, Shi L, Lin Y, Shi X, Li Z, Wu H, Dugarjaviin M, Bai D.The core objective of racehorse breeding is to enhance the speed and endurance of the horses. The Grassland-Thoroughbred is an emerging horse breed developed in northern China in recent years, characterized by excellent speed performance, enduring stamina, and strong environmental adaptability. However, research on the genetic characteristics within this breed and the genes associated with athletic performance remains relatively limited. We conducted whole-genome resequencing of Grassland-Thoroughbred F1, F2, F3, and the crossbred population (CY) and obtained a total of 4056.23 Gb of high-qual...
Avila F, Esdaile E, Bellone RR. Standardbreds, a breed of horses used in harness racing at either the trot or the pace, established a closed studbook in 1973. Concerns about genetic diversity within the breed led the United States Trotting Association (USTA) to establish a limit of mares bred per stallion (i.e., a studbook cap) in 2009. Here, we aimed to evaluate the impact of the breeding restrictions on genetic diversity between and among subpopulations. : Sixteen short tandem repeats (STRs) were analyzed across a dataset of 176,424 Standardbreds foaled in the United States between 1998 and 2021. We examined allelic richn...
Bazvand B, Rashidi A, Zandi MB, Moradi MH, Rostamzadeh J, Mahmoudi P.Iran is home to genetically distinct horse breeds shaped by geography and history. Breeds like the Kurdish, Caspian pony, and Turkmen reflect deep-rooted diversity and unique adaptive traits. Objective: This study aimed to identify genomic regions exhibiting signatures of selection and to detect candidate genes and biological pathways related to body size that may influence performance in various Iranian and exotic horse breeds. Methods: Samples were collected from three Iranian native breeds (Caspian pony, Turkmen, and Kurdish) and three exotic breeds (Fell pony, Arabian, and Akhal-Teke) orig...
Ennsmann LH, Licka TF.Most horses are used with horseshoes additionally supported by either dorsoabaxial or dorsal clips. The effects of such clips on bone density and shape of the distal phalanx are currently unclear. The aim of this study was to identify correlations between density and shape of the distal phalanx, comparing front hooves unshod or shod with standard shoes either with two dorsoabaxial clips or with a single dorsal clip. Researchers analyzed Oxspring radiographs of either the left or right front hoof from warmblood horses ( = 137) and ponies ( = 43) aged 3-28 years. The evaluation focused...
Corbally AF, Mulligan FJ, Sweeney T, Fahey AG.This study examines the associations between linearly scored phenotypic traits and auction sales prices of young event horses in Ireland, aiming to identify key traits influencing market value. Data from 307 horses sold at public auctions (2022-2023) were analysed using regression analysis, binary optimisation, and Principal Component Analysis (PCA). Regression identified Head-neck Connection, Quality of Legs, Walk length of Stride, and Scope as highly significant predictors of sales price ( < 0.001), with Length of Croup, Trot Elasticity, Trot Balance, and Take-off Direction also significa...
Staiger EA, Pereira de Toledo A, Rizzato Paschoal V, Patterson Rosa L.Horse gaits are a trait highly selected and prized in diverse breeds. Meanwhile, gait classification relies mostly on subjective visual observations by evaluators. Noninvasive equipment able to track locomotion in horses and output quantitative gait parameters is not only helpful in evaluating locomotion but also in designating gait types and its variations. Equine locomotion pattern designation based solely on observer evaluation can be subjective; therefore, utilizing tools that provide quantitative results and track individual limb movements, especially during intermediate-speed gaits, can ...
Choi Y, Jung Y, Wickens CL, Yoon M.Horses are social animals, with early life experiences playing a crucial role in their physiological and behavioral development. This study explored the influence of herd dynamics and foundational training on behavioral and hormonal changes in weaned foals. We examined 13 six-month-old Quarter Horse foals over a three-month training period, performing behavioral observations, temperament assessments, and hormone analyses at the start, midpoint, and end of the training. The results indicated that affiliative behaviors decreased significantly, while agonistic behaviors first increased and then d...
Calle-González N, Rivero JL, Argüelles D, Requena F, Muñoz A.Capacitive resistive electrical transfer (CRET) is a non-invasive electromagnetic diathermic technique. The effect of its application 24 h prior to exercise, compared to a sham application performed with the device off, was evaluated in 8 Spanish Purebred dressage stallions. CRET was applied bilaterally on the neck, back, and croup. The horses wore an accelerometer fixed on the sternal area during a dressage test, and spatiotemporal stride parameters, total and dorsoventral (DVAA), longitudinal (LAA), and mediolateral accelerometric activities, as well as dorsoventral displacement, were recor...
Kim T, Lee S, Seo JP.Foot diseases are common causes of lameness in horses. Computed tomography (CT) is a valuable tool for diagnosing musculoskeletal lesions in horses and providing a detailed evaluation of foot diseases. Objective: The objective of this study was to establish reference ranges related to the feet of normal Jeju horses by measuring the angles and length of the hoof, and the Hounsfield Unit (HU) value of soft tissues in the foot. Methods: Sixteen normal Jeju horses (mean age: 4.25 years; mean body weight: 282.06 kg) without lameness were examined using CT. After CT scanning, the angles and lengths ...
Armangau M, Lurier T, Josson A.Offspring Sex Ratio (OSR) at birth in mammals is generally assumed to follow a 1:1 male-to-female distribution, yet deviations in OSR have been observed and may be influenced by maternal and paternal factors. In this study we have focused on the effect of paternal factors (stallion age and breed) and breeding methods on the OSR. Using a retrospective dataset of 251,783 foal births recorded in France between 2015 and 2024, we applied generalized linear mixed models to evaluate the effects of these variables on the likelihood of producing a female foal. Stallion identity was included as a random...
Valera M, Encina A, Sánchez-Guerrero MJ, Rodríguez-Sainz de Los Terreros A, Bartolomé E.Behavioral and emotional reactivity assessment in sport horses is essential for optimizing their management and sports performance, particularly in equestrian disciplines such as Dressage. This study investigates, in Pura Raza Española (PRE) horses, the association between facial hair whorl (FHW) patterns, behavioral traits, and physiological stress responses using ocular temperature (OT) assessed with infrared thermography as, an objective, non-invasive physiological stress indicator. Unassigned: A total of 98 male PRE horses, aged 4-6 years old and all gray coated, were evaluated during the...
Watson WL, MacKay JRD, Dwyer CM.This study focuses on recreational horse owners in the UK and Ireland to explore the relationship between horse characteristics and welfare issues. An online questionnaire was distributed to 1501 horse owners to collect data on the owners, horses, and health/behavioural issues. Most respondents were female (98%), lived in England (56%), and did not insure their horses for veterinary costs (51%). Horses were typically over 5 years of age (96%), taller than 154 cm (55%), and mostly geldings (65%). Common welfare issues reported included lameness (26%), handling problems (11%), antisocial behavio...
