Morphometry in horses refers to the quantitative analysis of the form, structure, and size of horses. This scientific discipline involves measuring various physical dimensions and proportions of horses to assess their conformation, growth patterns, and breed characteristics. Common morphometric parameters include body length, height at the withers, girth circumference, and limb proportions. These measurements can provide insights into the suitability of horses for specific disciplines, their health status, and genetic traits. This page compiles peer-reviewed research studies and scholarly articles that explore the methodologies, applications, and implications of morphometric analysis in equine science.
Hmb O, L W, M V, Jm W, Ct F.A systematic study of regional skin thickness in different types of horses has not yet been described. Knowledge about regional skin thickness has long been used in human medicine to optimise wound care and skin grafting outcomes and similar knowledge could prove useful in equine wound management. The objective of the current study was to report the topographical variation in skin thickness of Warmblood (WB) and Coldblood (CB) type horses and to compare different methods for measuring skin thickness. Horses free of skin conditions and euthanised for reasons unrelated to this study were include...
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...
de Castro Sasahara TH, Gomes SP, Abdala FCM, Schimming BC, Miglino MA.Sexual differentiation in the equine fetus involves coordinated morphogenetic processes that shape both the gonads and the genital ducts. Although the formation of testes and ovaries has been relatively well documented, the temporal dynamics and morphometric patterns of the mesonephric (Wolffian) and paramesonephric (Müllerian) ducts remain insufficiently characterized. This study aimed to detail the timeline of gonadal and ductal differentiation in male and female equine fetuses during the critical developmental window between 60 and 80 days of gestation. Gross anatomical evaluation, histo...
Heilen LB, Roßgardt J, Dern-Wieloch J, Vogelsberg J, Staszyk C.Horses' hypsodont (high-crowned) teeth face permanent dental wear. This is compensated for by a continuous eruption, which requires a high adaptability of odontoblasts; otherwise, the dental pulp would be exposed. Here, we report on how equine odontoblasts respond to the challenge of maintaining a high production rate of dentin. We analyzed CD90, a marker of odontoblastic differentiation, and nestin, a marker of mature odontoblasts, in equine pulpal tissue via immunofluorescence. For comparison, we examined the hypselodont (ever-growing) incisors and brachydont (short-crowned) molars of rats. ...
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...
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...
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 ...
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...
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 ...
DÃaz-Bertrana ML, Pitti L, RamÃrez 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 ...
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...
González-Medina S, Barrett MF, Aboellail TA, Nelson BB, Nout-Lomas YS.While computed tomographic (CT) myelography is increasingly available and has been evaluated in alive horses, objective criteria for diagnosing cervical vertebral compressive myelopathy (CVCM) are lacking. Objective: To establish morphometric dimensions of the cervical vertebral canal and spinal cords from horses with CVCM and compare those to unaffected horses with the use of cone beam CT (CBCT). Methods: Prospective observational study. Methods: Four control horses and ten horses with CVCM underwent diagnostic imaging and histopathology. Morphometric measurements were obtained from cervical ...
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 ...
Mousquer MA, Paz CFR, Rafael LA, Wendt CG, Curcio BR, Souza RP, Santos IPOD, da Silva RB, Müller V, Nogueira CEW.Obesity is common in some horse breeds, raising concerns about health and performance. Criollo horses in morphological events often undergo intensive management promoting early adiposity. Objective: This study aimed (1) to assess morphometric traits, metabolic profile, hoof morphology, and tarsal joint alterations in Criollo horses participating in morphological trials; (2) to evaluate sex-related differences; and (3) the associations between morphometric measurements, hoof morphology, and tarsal osteoarthritis grades. Methods: Fifty-five horses (30 mares, 25 stallions) were evaluated for body...
Selecky ME, Louie EW, Donnelly C, Finno CJ, Morgan JM.Echocardiographic reference intervals for Quarter Horses are infrequently reported. Objective: To provide standard echocardiographic measurements for sedentary Quarter Horses and evaluate the relationship between physical characteristics (body weight, age, sex) and echocardiographic measurements. Methods: Forty-one sedentary Quarter Horses, free of cardiac disease, from a university research herd. Methods: A cross-sectional study evaluating standardized echocardiograms performed on sedentary Quarter Horses (41) between 2020 and 2022. Reference intervals were calculated for raw and weight-corre...
Freitag GP, de Lima LGF, Kozicki LE, Souza FA, Nogueira E, Ribeiro LB.This study investigated the influence of morphometric characteristics on performance in Quarter Horses competing in barrel racing. Methods: A total of 125 horses were assessed using 28 linear and angular body measurements derived from standardized left-side photographs captured via smartphone and analyzed with open-source software. Results: Measurements were subjected to exploratory factor analysis, extracting six principal components (forequarters, hindquarters, midsection, posterior angles, scapular traits, age and weight), which together explained 83.0 % of the morphological variance. Foreq...
Böck MJ, Fernandez TJ, Pereira VP, da Veiga ML, de Mello Bertoncheli Dos Santos C, de Morais-Pinto L.We examined 52 horse aortas to characterize the morphological aspects of the aortic bulb wall and the ascending aorta. The morphometric data were analyzed using ImageJ®-Fiji 1.5 software. The Tunica intima was composed of endotheliocytes with scarce cytoplasm and ellipsoid nuclei, supported by a collagenous subendothelial stratum. The Tunica media was composed entirely of fascicles of vascular smooth muscle cells interspersed with bundles of collagen fibers and elastic lamellae, characterizing the aortic medial lamellar unit. The Tunica adventitia consisted of two distinct sub-layers: the ext...
Miles S, McCauley C, Carossino M, Del Piero F, Liu CC, Gaschen L.Manica flexoria tears are increasingly recognized as a cause of lameness in horses resulting in a need for improved pre-operative diagnosis. Partial tears are difficult to pre-operatively diagnose and thus research for diagnostics of manica flexoria tears has been seen in increasing frequency over the past decade, though a deficit of information exists for the features of this structure on MRI, which is best suited for evaluation of soft tissues. The goal is to perform an observational study on the morphometry of the normal manica flexoria prospectively and describe it retrospectively on MRI. ...
Underberg BA, Kaessmeyer S, Schweizer D, Drews B, Van der Vekens E.The objective of this study was to establish a non-contrast enhanced MR angiography (NC-MRA) sequence for the equine foot (EF) using a post-mortem angiography model. Unassigned: Time-of-flight (TOF) sequences were tested using variable parameter settings and 3 slice orientations during vascular perfusion of frozen-thawed cadaver EF with paraffine oil. Transverse and dorsal orientations were planned perpendicular or parallel to the sublamellar vascular plexus at the dorsal aspect of P3, or approximately perpendicular to the coronary plexus. Visibility of the coronary plexus, sublamellar plexus,...
Bowkett-Pritchard C, Bolt DM, Chang YM, Berner D.Equine foot radiographs are commonly obtained to measure anatomical conformation parameters. Comparison of measurements between radiographs and low-field magnetic resonance imaging (MRI) has not been extensively explored. Objective: To compare foot parameter measurements between radiographs and low-field MRI, and assess the effect of hoof wall markers on visualising the hoof capsule (during MRI) and facilitating measurements. Methods: Comparative cadaveric analytical study. Methods: Radiography and MRI of nine equine cadaver front feet were performed with and without hoof wall markers, which w...
Zupan Šemrov M, Přibylová L, Gobbo E.Equine locomotion emerges from a dynamic interplay between morphology, biomechanics, and functional demands. This study examines the relationship between morphological measurements and gait kinematics in Lipizzan horses, a breed renowned for its diverse work tasks and standardized environmental conditions. These horses offer a unique opportunity to explore task-specific adaptations in biomechanics, with significant implications for breeding strategies and welfare practices. Unassigned: The study involved 71 healthy Lipizzan horses that were housed at the Lipica stud farm and performed various ...
Gómez-Torres F, Ballesteros-Acuña L, RuÃz-Sauri A.Arrhythmic sudden cardiac death in dogs and horses often results from ventricular arrhythmia secondary to myocardial damage. Despite this, limited data exist on the histomorphometric changes in cardiac conduction fibers (CCFs) and cardiac conduction cells (CCCs) following spontaneous myocardial infarction (MI). This study aimed to characterize morphometric and histological alterations in conduction fibers and their junctions with cardiomyocytes in infarcted hearts of horses and dogs. Unassigned: Ten hearts from horses and 10 from dogs that had died suddenly were examined. Histological and immu...
Dash SK, Panda S, Karna DK, Mishra C, Kalaignazhal G.The present study aimed to identify significant morphometric traits in Malkangiri ponies of Odisha through principal component analysis. The data were collected randomly from 200 ponies aged more than five years and 13 morphometric traits alongwith three indices were recorded. The mean height at wither, height at croup, body length, chest girth, punch girth, height at forearm, height at hock, fetlock to coronet, chest width, neck circumference, poll to wither, wither to croup and croup to head of the tail were 126.7 ± 0.39, 122.6 ± 0.29, 107.9 ± 0.2, 122 ± 0.31, 118.6 ±â...
Engiles JB, Stefanovski D, van Eps A.To examine the effects of prolonged preferential weight bearing (PWB) and reduced ambulation (RA) on hoof lamellae using a nonpainful in vivo experimental model. Unassigned: 12 healthy Standardbred horses were housed in stocks continuously for 92 hours. A platform shoe was placed on 1 forelimb in the PWB group (n = 6) to increase the load on the supporting limb (SL) by approximately 10% bodyweight, whereas the RA group (n = 6) had normal weight bearing. Archived healthy horse (n = 8) samples were used as controls. Histomorphometry and histochemistry (terminal deoxynucleotidyl transferase dUTP ...
Son JK, De Paz P, Kim J, Sanaei R, Ryu S, Bailey S, Davies HMS.Changes in the third metacarpal (MC3) mid-diaphyseal dimensions were measured radiographically in young Thoroughbred racehorses through race training and found to be associated with a higher risk of shin soreness. However, it is still unclear whether such negative MC3 morphologies are set congenitally or through development. Objective: To quantify MC3 bone dimensional changes through growth. Methods: Longitudinal. Methods: Twenty privately owned Thoroughbred foals were radiographed bimonthly from birth to 14 months of age. Four linear MC3 parameters (proximodistal MC3 length, mid-diaphyseal do...
MacKechnie-Guire R, Clayton H, Williams J, Marlin D, Fisher M, Fisher D, Walker V, Murray R.Measuring tools designed to objectively determine equine noseband tightness are inserted on the dorsal nasal planum in a rostro-caudal direction. The lateral aspect of the horse's head has several areas where minimal soft tissue intervenes between the skin and underlying bone, which makes them potentially useful sites for measuring noseband tightness. One hundred horses were fitted with a snaffle bridle with a cavesson, Swedish or dropped noseband in random order. The tightness of each noseband type was adjusted sequentially to 2.0, 1.5, 1.0, 0.5 and 0.0 finger-equivalents using an ISES Taper ...
Ahmad I, Ijaz S, Usman MM, Safdar A, Khan IU, Zeeshan M, Bukhari SSUH.Measuring limb joint angles is crucial for understanding horse conformation, performance, injury diagnosis, and prevention. While Thoroughbred horses have been extensively studied, local Pakistani breeds (e.g., Morna racehorse) have not received scientific attention. This study aimed to quantify normal angles of limb joints in the Morna breed. Limb joint angles of standing horses (n = 50) were quantified using a measuring tape, height stick, protractor scale, and goniometer. The mean and standard deviation (Mean ± SD) values for the forelimb joint angles were 123.02 ± 3.46° for elbow, 171.5...
Korsós SA, Kibleur P, Josipovic I, Boone M, Vlaminck L.In orthograde endodontic treatments, different methods are available to debride the pulp canals of endodontically compromised equine cheek teeth, but their efficacy is unknown. Objective: To explore and compare the efficacy and anatomical changes caused by manual versus reciprocating filing techniques in equine cheek teeth, to explore the presence of instrumentation mishaps described in human dentistry and to explore anatomical complexities of the pulp cavity that often remain uninstrumented using microcomputed tomography (μCT). Methods: Ex-vivo randomised experiments. Methods: Twenty-two ext...
Schaus K, Wacker J, Jandowsky A, Büttner K, Röcken M, Bartmann CP.Morphometric measurements of the toe serve as a reference for the objective assessment of the presence of a pathological condition and as a guide for the correct trimming of the hooves. Therefore, the anatomical differences between horses and donkeys oblige an autonomous database with reference values for the donkey. The aim of this study was therefore to provide readings of the distal hind limb on radiographs of donkeys. Radiographs of the distal hind limb in two projections of 41 generally sound donkeys without lameness in walk were taken after previous hoof trimming and preparation accordin...
Stone KC, Mercer RR, Gehr P, Stockstill B, Crapo JD.Allometric studies have shown that lung volume, alveolar surface area, and diffusing capacity increase proportionally with body weight across a broad range of mammalian species. Changes in the number of cells and in average cell size and surface areas with increasing body weight have not been defined. We speculated that cell size is determined more by cell function than by species and body weight. To test this hypothesis, nine species ranging in size from shrew (2 to 3 g) to horse (510 kg) were studied. Random sites from the distal alveolar region of each species were analyzed using morphometr...
Carroll CL, Huntington PJ.Three hundred and seventy two horses of varying breeds, height and fatness were weighed and measured for height at the withers. They were assessed for condition score by adaptation of a previously published method. The heart girth and length of 281 of the horses were also measured. Weight of horses was highly correlated (P less than 0.001) with height (r2 = 0.62), condition score (r2 = 0.22) and girth2 x length (r2 = 0.90). Nomograms were constructed to predict weight from height and condition score, and girth and length measurements. Weight can also be accurately estimated from the formula: (...
Carter RA, Geor RJ, Burton Staniar W, Cubitt TA, Harris PA.This study described a scoring system for the assessment of apparent neck adiposity and evaluated morphometric measurements for assessment of neck and overall adiposity. Twenty-one barren Thoroughbred mares, 13 Arabian geldings and 75 Welsh, Dartmoor, or crossbred pony mares, were clinically examined and blood samples analysed for insulin, glucose, leptin, and triglycerides. Bodyweight (BW), height, length, girth and abdominal circumferences, neck length, neck crest height and neck circumference were measured, and body condition scores (BCS) and cresty neck scores (CNS) were rated. Girth:heigh...
Payne RC, Hutchinson JR, Robilliard JJ, Smith NC, Wilson AM.We provide quantitative anatomical data on the muscle-tendon units of the equine pelvic limb. Specifically, we recorded muscle mass, fascicle length, pennation angle, tendon mass and tendon rest length. Physiological cross sectional area was then determined and maximum isometric force estimated. There was proximal-to-distal reduction in muscle volume and fascicle length. Proximal limb tendons were few and, where present, were relatively short. By contrast, distal limb tendons were numerous and long in comparison to mean muscle fascicle length, increasing potential for elastic energy storage. W...
Thatcher CD, Pleasant RS, Geor RJ, Elvinger F.The prevalence of obesity in horses in the eastern United States is not well documented. Objective: To determine body condition and risk factors for obesity in horses in Southwest Virginia during summer. Methods: A sample of 300 mature (4-20 years old), light breed horses (140 mares, 151 geldings, and 9 stallions) from the VMRCVM Equine Field Service practice equine database. The horses were from 114 farms and 138 owners. Methods: Horses were evaluated over a 60-day period in this cross-sectional, prospective study. A questionnaire was completed for each horse. Body condition score (BCS) was a...
McMahon TA.Many parameters of gait and performance, including stride frequency, stride length, maximum speed, and rate of O2 uptake are experimentally found to be power-law functions of body weight in running quadrupeds. All of these parameters are reasonably easy to measure except maximum speed, where the question arises whether one means top sprinting speed or top speed for sustained running. Moreover, differences in training and motivation make comparisons of top speed difficult. The problem is circumvented by comparing animals running at the transition between trotting and galloping, a physiologicall...
Biewener AA.Measurements of the cross-sectional geometry and length of bones from animals of different sizes suggest that peak locomotory stresses might be as much as nine times greater in the limb bones of a 300 kg horse than those of a 0.10 kg chipmunk. To determine if the bones of larger animals are stronger than those of small animals, the bending strength of whole bone specimens from the limbs of small mammals and bipedal birds was measured and compared with published data for large mammalian cortical bone (horses and bovids). No significant difference (P greater than 0.2) was found in the failure st...
Hayes S, Boote C, Lewis J, Sheppard J, Abahussin M, Quantock AJ, Purslow C, Votruba M, Meek KM.This study is a comparative study of the relationship between corneal structure, morphology, and function in a range of mammalian species. X-ray scattering patterns were gathered at regular spatial intervals over the excised cornea (and in most cases also the scleral rim) of humans, marmosets, horses, cows, pigs, rabbits, and mice. All patterns were analyzed to produce quantitative information regarding the predominant orientation of fibrillar collagen throughout the tissue. The predominant direction of corneal collagen varies between mammals. This variation is not related to the size, shape, ...
Payne RC, Veenman P, Wilson AM.Muscles have two major roles in locomotion: to generate force and to absorb/generate power (do work). Economical force generation is achieved by short-fibred pennate muscle while the maximum power output of a muscle is architecture independent. In this study we tested the hypothesis that there is an anatomical and structural separation between the force-generating anti-gravity muscles and the propulsive (limb/trunk moving) muscles of the equine forelimb. Muscle mass and fascicle length measurements were made on the thoracic limb extrinsic muscles of six fresh horse cadavers. Physiological cros...
Jensen RB, Danielsen SH, Tauson AH.Obesity is related to the development of several diseases like insulin resistance and laminitis in horses. The prevalence of obesity among mature Icelandic horses in Denmark has not been investigated previously. This study aimed to find the prevalence of obesity, to compare body condition score (BCS) based on owner perception with that of an experienced person and to correlate the BCS to body weight (BW) and morphometric measures in a group of mature Icelandic horses in Denmark. A total of 254 Icelandic horses (≥4 years; 140 geldings, 105 mares, 9 stallions) from 46 different farms were inc...
Dugdale AH, Curtis GC, Harris PA, Argo CM.Evaluation of equine body fat content is important for nutritional and clinical purposes. However, our understanding of total body fat and its regional distribution in the body is sparse. Currently, body fat evaluation relies on the subjective assessment of body condition score (BCS), which has never been validated against 'gold standard' chemical analysis or dissection measurements in ponies. Objective: To define the relationships between subjective (BCS), objective (morphometric) indices of body fat and 'gold standard' measurements of actual body composition. Objective: BCS and morphometry o...
Russell LD, Ren HP, Sinha Hikim I, Schulze W, Sinha Hikim AP.Morphometric studies were performed on 12 mammalian species (degu, dog, guinea pig, hamster, human, monkey, mouse, opossum, rabbit, rat, stallion, and woodchuck) to determine volume density percentage (Vv%), volume (V), and numerical density (Nv) of seminiferous tubule components, especially those related to the Sertoli cell, and to make species comparisons. For most species, measurements were taken both from stages where elongate spermatids were deeply embedded within the Sertoli cell and from stages near sperm release where elongate spermatids were in shallow crypts within the Sertoli cell. ...
Skedros JG, Mason MW, Nelson MC, Bloebaum RD.Functionally induced strains provide epigenetic signaling for bone modeling and remodeling activities. Strain gauge documentation of the equine third metacarpal reveals a neutral axis passing through the craniolateral cortex, resulting in a narrow band of cortex loaded predominantly in tension, with the remainder of the cortex experiencing a wide range of compression strain magnitudes that are maximal in the caudomedial cortex. This predictable strain pattern provides a model for examining the hypothesis that strain mode, magnitude, and strain energy density are potential correlates of compact...
Kayar SR, Hoppeler H, Mermod L, Weibel ER.Individual mitochondria were reconstructed from ultrathin serial sections of selected muscle fibers in the M. semitendinosus of a horse, over a length of nearly two sarcomeres. Mitochondria were found to be highly variable, with size and complexity of single mitochondria increasing with the fractional part of a fiber occupied by mitochondria. In fibers with a mitochondrial volume density of less than 4%, corresponding to the mitochondrial content of fast-twitch glycolytic fibers, mitochondria were generally rather simple cylindrical shapes, oriented parallel to the myofibrils. In fibers with a...
Kaiser TM, Fortelius M.A new approach of reconstructing ungulate diet, the mesowear method, was recently introduced by Fortelius and Solounias ([2000] Am Mus Novitat 3301:1-36). Mesowear is based on facet development on the occlusal surfaces of the teeth. Restricting mesowear investigation to maxillary cheek teeth would allow mesowear investigation only in assemblages of large numbers of individuals and therefore would generally restrict this method to relatively few assemblages of recent and fossil ungulates. Most of the fossil, subfossil, and recent ungulate osteological assemblages that may be assigned to a singl...
Townsend HG, Leach DH.The anatomical features of 21 equine thoracolumbar spines, obtained from horses with clinically normal backs, were examined and the results compared with recent data on the mobility of the joint complexes of the horse's spine. The thoracolumbar spine can be divided into four regions based upon the morphology of the joint complexes: the first thoracic intervertebral joint (T1-2), the cranial and mid thoracic region (T2-T16), the caudal thoracic and lumbar region (T16-L6) and the lumbosacral joint. The mobility of the intervertebral joints in each of these regions can be related to their morphol...
Witte H, Biltzinger J, Hackert R, Schilling N, Schmidt M, Reich C, Fischer MS.In three species of small therian mammals (Scandentia: Tupaia glis, Rodentia: Galea musteloides and Lagomorpha: Ochotona rufescens) the net joint forces and torques acting during stance phase in the four kinematically relevant joints of the forelimbs (scapular pivot, shoulder joint, elbow joint, wrist joint) and the hindlimbs (hip joint, knee joint, ankle joint, intratarsal joint) were determined by inverse dynamic analysis. Kinematics were measured by cineradiography (150 frames s(-1)). Synchronously ground reaction forces were acquired by forceplates. Morphometry of the extremities was perfo...
Muir P, Peterson AL, Sample SJ, Scollay MC, Markel MD, Kalscheur VL.Repetitive bone injury and development of stress fracture is a common problem in humans and animals. The Thoroughbred racehorse is a model in which adaptive failure and associated development of stress fracture is common. We performed a histologic study of the distal end of the third metacarpal bone in two groups of horses: young Thoroughbreds that were actively racing (n = 10) and a group of non-athletic horses (n = 8). The purpose of this study was to determine whether development of articular microcracks was associated with specific alterations to subchondral plate osteocytes. Morphometric ...
Patterson-Kane JC, Parry DA, Birch HL, Goodship AE, Firth EC.The superficial digital flexor tendon is the most commonly injured tendon in the racing Thoroughbred. Despite the clinical significance of this structure, only limited data exist regarding normal age-related morphology of the tensile units, the collagen fibrils. The age at which these collagen fibrils become mature in composition and structure may be of importance. Consequently, the association of age and collagen fibril crosslink composition, diameter distribution and crimp morphology in the superficial and deep digital flexor tendons of Thoroughbreds up to and including three years of age ha...
Rustin M, Janssens S, Buys N, Gengler N.Genetic parameters for the height at withers, 27 linear type and six linear gait traits were estimated for the Belgian warmblood horse. Observations on 987 mares, mostly 3 years old, were analysed using a multi-trait animal model. The statistical model included appraiser, age and location (date x place of appraisal) as fixed effects. Genetic parameters were estimated using a canonical transformation and an expectation-maximization restricted maximum likelihood algorithm with an additional deceleration step. Estimates of heritability for the 33 linear traits were between 0.15 and 0.55. Heritabi...
Ravara B, Gobbo V, Carraro U, Gelbmann L, Pribyl J, Schils S.Functional Electrical Stimulation (FES) has been used extensively over several decades to reverse muscle atrophy during rehabilitation for spinal cord injury patients. The benefits of the technology are being expanded into other areas, and FES has been recently utilized for injury rehabilitation and performance enhancement in horses. Six retired horses (age from 10 to 17 yrs) that had been previously used mainly for dressage riding were selected for this study. Clinical evaluation found epaxial muscle spasms in all horses with minimal to no pelvic extension when manually palpated. FES treatmen...
Rivero JL, Talmadge RJ, Edgerton VR.The histochemical myofibrillar ATPase (mATPase) method is used routinely for identification of equine skeletal muscle fiber types, but important problems have been observed with the subdivision of fast fiber population when using this method. To verify the use of this qualitative method, a number of equine muscle biopsies were analyzed with a combination of histochemical, immunohistochemical, electrophoretic, and morphometric techniques. The influence of training on these interrelations was also evaluated. Methods: Five young (2-3 years old) thoroughbred horses were intensively trained for 8 m...
Pearson RA, Ouassat M.The age, sex, liveweight and body measurements (heart girth, umbilical girth, height, length from elbow to tuber ischii and circumference of the foreleg cannon bone) of 516 donkeys used to transport goods in Morocco were recorded. There were few donkeys over 12 years of age. For adult donkeys weighing from 74 to 252 kg, the best equation with only one variable for predicting liveweight was: liveweight (kg) = heart girth (cm)2.65/2188. The inclusion of two variables improved the prediction marginally, but the addition of further variables gave little further improvement. The best prediction equ...
Watson JC, Wilson AM.Three muscles from the proximal equine forelimb were dissected in order to investigate their potential to contribute to proximal limb mechanics. Muscle mass, fibre length, tendon mass and tendon length were measured from biceps brachii, triceps brachii, supraspinatus and lacertus fibrosus (biceps lateral head mass 171-343.4 g and fibre length 0.5-0.8 cm; biceps medial head mass 283-500 g and fibre length 2.2-4 cm; biceps tendon mass 121.8-260 g and tendon length 35-44 cm; triceps long head mass 3200-6663 g and fibre length 19-26.3 cm; triceps lateral head mass 513.8-1240 g and fibre length 17....
Heintzman PD, Zazula GD, MacPhee R, Scott E, Cahill JA, McHorse BK, Kapp JD, Stiller M, Wooller MJ, Orlando L, Southon J, Froese DG, Shapiro B.The extinct 'New World stilt-legged', or NWSL, equids constitute a perplexing group of Pleistocene horses endemic to North America. Their slender distal limb bones resemble those of Asiatic asses, such as the Persian onager. Previous palaeogenetic studies, however, have suggested a closer relationship to caballine horses than to Asiatic asses. Here, we report complete mitochondrial and partial nuclear genomes from NWSL equids from across their geographic range. Although multiple NWSL equid species have been named, our palaeogenomic and morphometric analyses support the idea that there was only...
Miller MA, Pardo ID, Jackson LP, Moore GE, Sojka JE.Functional evaluation of the pars intermedia (PI) is required for the early diagnosis of equine pituitary PI dysfunction (PPID), yet most assays target the hypothalamic-pituitary-adrenal axis, which regulates the pars anterior. In contrast, the PI is regulated by dopaminergic tone from hypothalamic neurons. Loss of dopaminergic inhibition is hypothesized to cause the PI hypertrophy and hyperplasia that result in the clinical manifestations of PPID. Domperidone, a dopamine receptor antagonist, should exacerbate the loss of dopaminergic inhibition in horses with PPID and increase the release of ...
Bullone M, Chevigny M, Allano M, Martin JG, Lavoie JP.Morphometric analyses of endobronchial biopsies are commonly performed in asthma research but little is known about the technical and physiological parameters contributing to measurement variability. We investigated factors potentially affecting biopsy size, quality, and airway smooth muscle (ASM) content in heaves, an asthma-like disease of horses. Horses with heaves in clinical exacerbation (n = 6) or remission (n = 6) from the disease and six controls were studied using a crossover design. The effect of disease status, age, bronchodilation, biopsy forceps type, and carina size on total biop...
