Morphology in horses refers to the study of the form and structure of the equine body, including the skeletal, muscular, and integumentary systems. This field encompasses the examination of physical characteristics such as body conformation, limb structure, and cranial features, which can influence a horse's performance, health, and suitability for various activities or disciplines. Morphological assessments are often used in breeding programs to select for desirable traits and in veterinary evaluations to identify potential anatomical issues. This page aggregates peer-reviewed research studies and scholarly articles that explore the methodologies, findings, and implications of morphological studies in equine science.
Riahi Z, Naeini AT, Zare R.Dareshuri horses are the predominant breed in Fars Province, Iran. Although disorders affecting their maxillary cheek teeth and maxillary sinuses are relatively common, limited fundamental data are available on the dimensions and relationships of these structures at different ages. Given the significant anatomical changes in the heads of young horses as they mature, this study aimed to evaluate age-related changes in the position and anatomical relationships of individual maxillary cheek teeth within the rostral and caudal maxillary sinuses (RMS and CMS, respectively), as well as changes in th...
Karlau A, Azcona F, Molina A, Trigo P, Sánchez-Serrano JP, Demyda-Peyrás S.The Peruano de Paso is a horse breed renowned for its smooth gait, traditionally selected based on breeders' empirical knowledge. Recently, the frequency of chestnut horses, a recessive trait, has increased substantially within the official studbook. This study evaluated whether preference for chestnut coat colour has influenced morphological traits and genetic diversity within the breed. A total of 8376 records of seven morphological traits, collected by the Peruano de Paso Breeders Association over eight years, were analysed, along with a pedigree including 41,357 individuals. Morphological ...
Garland A, van Doorn DA, van den Boom R, Roelfsema E, Jung L, Boast M, Papadakis K, Margiotta M, Wafelbakker S, Briggs M, McCrae P, Pearson W.Up to 70% of horses in domestic equine populations are overweight. Promotion of weight loss is an important component of limiting the detrimental co-morbidities associated with excess adipose tissue. The use of a body condition score (BCS) can help equine caregivers track their horse's weight-status. However, this single score doesn't reflect changes in individual adipose depots. The purpose of this study was to characterize morphometric changes (including 8 anatomic BCS measurements that make up the whole-BCS) in horses during 3 different weight-loss programs over 10 weeks. Methods: Thirty-tw...
Olijnyk JM, Hosgood G, Richardson J, Beggs C, McConnell E.Reliable assessment of foot conformation is essential for podiatric management in Miniature Horses and Ponies, yet reference ranges and the reliability of radiographic measurements remain poorly defined. Objective: This study quantified radiographic measurements of foot conformation in sound, skeletally mature Miniature Horses and Ponies and evaluated their agreement, reliability, and precision. Methods: Standardised lateromedial and dorsopalmar/plantarodorsal radiographs were obtained from 30 Miniature Horses and Ponies. Two observers took 60 measurements from 10 sets of projections on three ...
Díaz-Bertrana ML, Pitti L, Ramírez AS, Encinoso M, Fumero-Hernández M, Morales I, Arencibia A, Jaber JR.This study aimed to characterize the computed tomographic (CT) dimensions and contrast attenuation properties of the equine eye. CT scans from 21 horses without ocular abnormalities were analyzed to obtain detailed ocular measurements and attenuation values. In addition, cranial measurements, such as nasal-occipital length and zygomatic width, were incorporated to explore potential anatomical relationships between the skull and intraocular structures. Although most correlations between cranial and ocular parameters were weak, statistically significant associations-particularly those involving ...
Hellige M, Schröder C, Seehusen F, Rohn K, Geburek F.Computed tomographic myelography (CTM) is diagnostic for extradural spinal cord compression but knowledge about vertebral ratios from transverse images in flexion and normal position of unaffected horses is lacking. Objective: To compare the ratios of the cross-sectional areas (CSAs) of the spinal cord, the vertebral canal and of the contrast enhanced dural tube on transverse CTM images at C3-C4 in neutral and flexed positions in unaffected Warmbloods. Methods: CTM was performed in 13 neurologically unaffected Warmbloods in neutral and flexed cervical vertebral column positions. Ratios were ca...
Mohtasebi S, Ahn S, Karimi M, Saberi M, Gilleard JS, Poissant J.Strongyles pose significant health concerns for equids globally. Strongyles, comprising over 60 species, can lead to severe morbidity and mortality, with Strongylus vulgaris posing higher risks due to its migratory behaviour. Routine diagnostic methods, such as faecal egg counts, lack species-level resolution, while traditional morphological techniques require advanced expertise. DNA metabarcoding offers a high-throughput alternative. Objective: To characterise the diversity of strongyles infecting horses in northern Iran and evaluate how age, sex, diagnostic methods and host population influe...
Stachurska A, Wnuk E, Łuszczyński J, Donderowicz W.Correct conformation and symmetry of bilateral hooves are associated with a properly balanced hoof, which has a significant impact on the biomechanics of movement and reduces the risk of injury. The aim of the study was to compare solear aspect dimensions of bilateral hooves in forelimbs (hoof width, length, frog width, length, medial and lateral diagonals) with regard to sex, breed and age of horses. The dimensions were measured with a calliper in 100 horses of four breeds. The results showed that the breed factor significantly affected all dimensions. Age was significant for some variables, ...
Meeremans M, Devriendt B, Bairiot S, Van Poucke M, Peelman L, Demeyere K, Meyer E, Van Vlierberghe S, De Schauwer C.Macrophages play key roles in tissue homeostasis and regeneration-associated inflammation. Unlike humans, a reliable protocol to obtain and polarise equine monocyte-derived macrophages is lacking. In this study the polarisation of equine macrophages, derived from CD172a peripheral blood monocytes is described. After differentiation, IFN-γ/LPS or IL-4 were used to induce pro- and anti-inflammatory phenotypes, respectively. Evaluation criteria included morphology, mRNA (RT-qPCR) and protein expression (flow cytometry, immunofluorescence), nitric oxide and arginase production, cytokine secretion...
Sellke L, Ludewig E, Handschuh S, Witter K.In a previous study on hoof biometry, we found that mathematical correction of measuring results from radiographs did not lead to complete correspondence to computed tomography (CT) results. The present study investigates this finding by comparing 13 measures of six cadaveric equine digits collected with the following workflows: radiographs with 1 and 2 m focus-object distance (FOD) (Xray 1 m/2 m), computed tomography images in planes defined based on anatomical landmarks (CTw), simulated radiographs based on the tomography dataset (virtual 120-mm slabs, Xray Sim) and measurements based ...
Bao Y, Wang T, Adina W, Yao R, Chu H, Yao X, Meng J, Wang J, Ren W, Zeng Y.This study aimed to investigate how different training outcomes affect the gut microbiota composition in racehorses. Twenty-six Yili horses underwent a 9-month conditioning training regimen under uniform husbandry and management conditions. Post-training, the horses were divided into an excellence group (D. Y group) and a general group (D. P group) based on their athletic performance, with the top 10 performers constituting the D. Y group and the bottom 10 the D. P group. Cardiac morphology and function were quantitatively assessed via echocardiography, and metagenomic sequencing was performed...
Sharma M, Singh A, Kumar V, Olla N, Arora R, Sharma R, Mohan NH, Ahlawat S.The genus Equus, encompassing horses, donkeys, and extinct relatives, has evolved over approximately 55 million years from small, multi-toed ancestors to the modern horse. Selective breeding has produced over 600 distinct horse breeds optimized for diverse traits such as size, conformation, performance, and adaptability. In the past two decades, rapid advances in equine genomics have significantly deepened our understanding of the molecular basis of these traits. The integration of high-throughput sequencing, genome-wide association studies (GWAS), and single-nucleotide polymorphism (SNP) geno...
Risvanli A, Salykov R, Timurkaan N, Seker I, Ekinci E.This study was conducted to examine glandular histological changes in the uterus of Kyrgyz breed mares during the first 6 months of pregnancy. The study used 53 Kyrgyz breed mares; 43 of these were at different stages of pregnancy, while 10 were non-pregnant mares. Uterine samples obtained at the slaughterhouse were evaluated histomorphometrically; endometrial thickness, gland density, gland epithelial height and gland diameter were measured. In conclusion, it was concluded that in Kyrgyz mares, endometrial thickness, glandular epithelial height and diameter increased as pregnancy progressed...
Underberg BA, Van der Vekens E, Drews B, Kaessmeyer S.Equine laminitis is a complex and potentially fatal disease characterized by severe vascular and inflammatory alterations within the equine foot. This study aimed to develop immunohistochemistry (IHC) protocols for the detection of cyclooxygenase-2 (COX-2) and von Willebrand factor (vWF) in equine feet with and without laminitis, post-mortem perfused with paraffin oil. Unassigned: A total of 12 equine forelimbs from 8 horses were utilized in this study, divided into two study cohorts: one with laminitis and the other as a non-laminitis control. To develop the IHC protocols thoroughly, the tiss...
Latorre N, Gómez-Cuétara C, Cañizares E, Crespo F, Pérez-Aguilera V, Cuerda MI, Laborda-Gomariz JA, Soler AJ, Roldan ERS, Sanchez-Rodriguez A.Evaluating semen quality in Purebred Spanish Horses is essential to determine reproductive potential and optimize assisted reproductive techniques. Objective: This study compared several sperm analysis methods in Purebred Spanish Horses to standardize protocols suitable for both laboratory and field conditions. Methods: Fifteen stallions were evaluated through three ejaculates, analyzing sperm parameters using different techniques. Sperm kinematics was assessed by Sperm Computer Analyzer (SCA-CASA) or iSperm mCASA. Viability was analyzed by eosin-nigrosin-Giemsa (ENG) staining or Hoechst 33258...
Aliani C, Lorenzetto Bologna C, Francia P, Bocchi L.Standing equine computed tomography (CT) acquisitions are susceptible to residual postural sway, which can introduce view-inconsistent motion and degrade image quality. External optical tracking based on ChArUco fiducials is a promising, low-cost strategy to enable projection-wise motion compensation, yet quantitative guidance on how camera-marker geometry affects pose-estimation performance remains limited. This CT-motivated benchtop study characterizes how the relative camera-ChArUco configuration influences both the accuracy (bias with respect to ground truth) and the precision (repeatabili...
DeClue A, Workman K, May-Davis S.To date, radiographically identifying the bony landmarks relevant to diagnosing the complete C6 aplasia of the caudal lamina ventralis (C6 aCLV4) has not been described. Furthermore, a gross study has identified C6 aCLV4 as the main correlation between transposition of the CLV from C6 to C7, where coinciding neck pain was commonly reported. This study aimed to identify C6 aCLV4 in radiographs, where the outcome might benefit equine practitioners in isolating neck pain. Initially, the relevant bony landmarks were radiographically determined from a normal C6 by applying a lateral 30° dorsal-ven...
Valberg SJ, Williams ZJ, Ames EG, Mickelson JR, Nout-Lomas YS, Landolt G, Sanz M, Gardner K.Equine myotonic dystrophy (eMD) is a rare neuromuscular disorder of undetermined origin marked by muscle hypertrophy and stiffness, dystrophic muscle histopathology, and myotonic discharges. In humans, myotonic dystrophy (DM) arises from trinucleotide repeat expansions in dystrophia myotonica protein kinase (DMPK) (DM1) or tetranucleotide expansions in cellular nucleic acid-binding protein (CNBP) (DM2), which disrupt mRNA processing and induce embryonic splicing patterns across multiple genes. In 6 eMD Quarter Horse types, (2-36 months-of-age) and 8 control Quarter Horses we determined: (1) fi...
Maeda T, Inoue S, Ringhofer M, Hirata S, Yamamoto S.Encounters between competitive individuals or groups are common in social animals and can involve costly aggression; thus, animals often employ strategies to minimize direct conflict. However, research on whether and how animals adjust their group spatial structure when they encounter or spatially co-occur with a different group remains limited. We investigated how non-territorial units in feral horse multilevel societies manage spatial encounters with neighbouring units. We observed 25 reproductive units in northern Portugal, using drones, and employed statistical analyses to quantify spatial...
Ver Goltz L, Gomes SP, Schimming BC, Abdala FCM, Miglino MA, de Castro Sasahara TH.The equine ovary exhibits unique structural and developmental features that distinguish it from those of other domestic species, including the presence of an ovulation fossa and an inversion of cortical and medullary layers. This study aimed to investigate the morphostructural development of the equine fetal ovary, with particular emphasis on the formation of the ovulation fossa. Fourteen female equine fetuses, ranging from 70 to 200 days of gestation, were collected from a commercial abattoir. Results revealed a progressive increase in ovarian volume and marked histological changes througho...
Țăpuc IM, Mureșan AN, Mircean M, Papuc I.Urinalysis is a valuable, non-invasive method for evaluating renal function, yet data on donkey urinary parameters remain scarce. This study characterised urinary sediment in fifty-four healthy adult jennies, established urine specific gravity (USG) reference intervals, and proposed a preliminary semi-quantitative sediment grading scale. Urine samples were collected via catheterisation and analysed using refractometry, dipstick testing, and microscopy. The median USG was 1.048 (IQR: 1.040-1.055) with a pH of 7.6 (IQR: 7.2-8.0). Leukocytes and glucose were absent; erythrocytes were found in one...
Ferrara MA, Preziosi G, Boni R, Ruggiero R, Gualandi SC.This study employs Holographic tomography (HT) to examine structural and biophysical changes occurring during the cryopreservation of stallion sperm. HT is an advanced imaging technique that integrates digital holography with tomography to achieve three-dimensional, quantitative reconstructions of objects without the need for treatment or reporter dyes. By using refractive index (RI) intervals to represent specific structural regions of sperm cells, variations in optical density, surface area, volume, and dry mass across different cryopreservation extenders and donors have been quantified. Thr...
Rodero E, González-Martínez A, Diz A, Rodero J.One of a veterinarian's routine tasks is animal identification, with age being a crucial factor in the identification and evaluation of individuals. Knowledge of the morphological changes in animal dentition used to determine their age is essential in veterinary education. Today's students increasingly prefer innovative learning tools that incorporate 3D anatomical models over traditional 2D resources. As part of a teaching innovation project at the University of Córdoba, Spain, new educational materials were developed to aid students in identifying the age of animals using 3D images of equin...
Yang S, Xiao J, Mu L, Li C, Dai S, Li S, Cui Y, Xu Y.Between the third and sixth centuries AD (Anno Domini), the Xianbei emerged as a dominant nomadic power in the Eastern Eurasian Steppe, distinguished by their exceptional equestrian culture and the pivotal role of cavalry in warfare. Despite their historical significance, detailed knowledge of their cavalry's weaponry and equipment-particularly armour-remains fragmentary. As a critical element of military technology, armour offers valuable insights into ancient combat strategies and cultural practices. However, research on early Chinese cavalry armour has been constrained by limited textual re...
Liu X, Liu A, Khan MZ, Zhu Q, Zheng Y, Chen W, Cai B, Yan Z, Peng Y, Wang C.The gene family plays an indispensable role in regulating embryonic development, cell differentiation, and morphogenesis. This study employed bioinformatics approaches for systematic analysis, ultimately identifying 33 gene family members from the donkey genome. Physicochemical property analysis revealed that the number of amino acids encoded ranged from 94 to 444, with 31 members classified as alkaline proteins. Their secondary structure was predominantly composed of random coils and alpha helices, and all members were localized to the nucleus. Conserved motif analysis further demonstrated ...
Larriva-González F, Erráez-Guaicha JE, Torres-Ordóñez KE, Duma M, Larriva-Salazar S, Galarza DA.This study evaluated the cryoresistance of stallion sperm frozen by ultra-rapid (UR) methods using microspheres and straws or by the conventionally-slow (CS) method. Sixteen ejaculates from four stallions were each divided into three aliquots according to the freezing method: UR freezing in 30-μL spheres (UR-Spheres) by direct immersion in liquid nitrogen (LN); UR freezing in 0.25-mL straws (UR-Straws) by direct horizontal submersion in LN; and CS freezing in LN vapors. Ultra-rapid freezing medium included 100 mM trehalose +1 % BSA, and the CS freezing medium contained 5 % dimethylformamid...
Lefèvre RA, Barluet de Beauchesne L, Sabarros F, Briefer Freymond S, Ramseyer A, Keller M, Reby D, Fitch WT, Briefer ÉF.Understanding why the frequencies of some species' vocalizations are far above or below those predicted by body size is key for explaining the remarkable diversity of mammalian vocal behavior. Horses, among the largest terrestrial mammals, provide a clear example of such deviation: their whinnies contain a very high fundamental frequency (>1,000 Hz) in addition to a second, lower one (∼200 Hz). While the lower fundamental frequency of whinnies is readily attributed to vocal fold (laryngeal) vibrations, the biomechanical processes underlying the production of the higher one remain unknown. Us...
Goodchild OA, Rosen SN, Mennecart B, Meng J, Tissier J.Perissodactyla, or odd-toed ungulates, are represented today by 16 species of rhinoceroses, tapirs, and horses. Perissodactyls were much more diverse in the past, having a rich fossil record spanning from the earliest Eocene (~56 Ma) to recent, including a myriad of extinct lineages. Despite over a century of study, the inter-relationships of some extinct perissodactyl families remain poorly resolved. New morphological characters are needed to help solve this issue. Recent studies suggest that the ear region, ., the petrosal and the bony labyrinth of the inner ear, is a valuable source of morp...
De Ridder T, Aerts P, MacLaren JA.Equid evolution is characterized by a high diversity of extinct species and morphologies, whereas extant equids share a superficially similar, monodactyl morphology. This inferred musculoskeletal similarity of modern equid limbs remains unexplored, and it is often assumed that domestic horse limbs are representative for wild equids (e.g., zebras, onagers, etc.). Our aim was to quantitatively describe the muscle architecture and arrangement of all forelimb muscles in extant wild Equus species to test this assumption, and investigate any differences between the species. We hypothesized that ther...
