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.
Gómez-Torres F, Ballesteros-Acuña L, Ruíz-Sauri A.Atrioventricular node is responsible for delaying the passage of the electrical impulse to ventricles in order to protect them from fast depolarizations coming from the atria. The importance of this study is to identify the morphological variations of the components of atrioventricular zone that affect the conduction system and its clinical relationship in different species of mammals. We analyzed ten human hearts, nine from horses, eight from pigs, and five from dogs without a clinical history of cardiac pathologies. Histological section thickness of 5 μm were obtained with a microtome and ...
Novello G, Segabinazzi LGTM, Lisboa FP, Canuto LE, Freitas-Dell'Aqua CP, Dell'Aqua JA, Canisso IF.This study compared the postthaw semen parameters of stallions with high and low body condition score (BCS) and evaluated associations between body morphometric parameters and postthaw semen parameters. Twenty stallions were split into Low BCS (BCS<7, n = 11) and High BCS (BCS ≥7, n = 9) groups, and underwent a complete morphometric analysis (e.g., neck scores and circumference, crest neck height, body weight, and height), and subcutaneous body fat thickness (SFT) at the tail head, withers, shoulders, and retroperitoneal space. A fasted oral sugar test (OST) was conducted on all stallio...
Olusa TAO, Akbar Z, Murray CM, Davies HMS.Despite many reported cases of carpal lameness associated with intercarpal ligament injuries in horses, the morphometry, movement pattern and general intrinsic biomechanics of the carpus are largely unknown. Using osteoligamentous preparation of the carpus prepared from 14 equine cadaver forelimbs (aged 9.62 ± 4.25 years), locomotory simulations of flexion and extension movements of the carpal joint were carried out to observed carpal biomechanics and, thereafter, the limbs were further dissected to obtain morphometric measurements of the medial and lateral collateral ligaments (MLC and LC...
Goldstein DM, Engiles JB, Rezabek GB, Ruff CB.The elongated, distally tapered limbs of horses are adapted for high-speed locomotion. Because these traits are artificially selected for in modern racehorses, they operate at a morphological extreme with a high risk of fracture. Racehorses are subject to different training and racing regimes depending on their breed and gait, and are therefore an interesting model to examine bone functional adaptation under variable biomechanically intense conditions. This study compares bone structural properties in the third metacarpal (MCIII) of Thoroughbred (n = 9) and Quarter Horse (n = 11) racehorses, u...
Camacho Benítez A, Vasconcellos R, Lombide P, Viotti H, Pérez W, Cazales N, Cavestany D, Martin GB, Pedrana G.Heat shock proteins play a crucial role in cellular development, proliferation, differentiation and apoptosis. Heat shock protein 90 (HSP90) has been localised in the human endometrium, where its immunoexpression changes during the menstrual cycle. Similar studies have not been done for the equid species, so the present study aimed to describe endometrial HSP90 immunoexpression in mare endometrium. Endometrial biopsies were formalin-fixed and paraffin-embedded, and sections were stained with haematoxylin-eosin in preparation for HSP90 immunohistochemistry. Immunostaining and morphometric analy...
Kau S, Failing K, Staszyk C.The angle encompassed between opposing incisors in horses is assumed to decline with age. Previous studies merely consider the overall profile view of clinical crowns presuming a generalized angle, neglecting potential tooth position-dependent differences. Cephalometric measurements from 3D computed tomographic thick-slab reconstructions of single incisors within a global reference frame were used to determine clinical crown interincisal angulation (IIA) of 48 horses. Based on predefined dentoalveolar landmarks, IIA was defined as the angle enclosed by the respective labial axis of the clinica...
Leśniak KG, Williams JM.Directionality of limb and facial asymmetries in nonelite equine populations has been previously reported with results indicating strong similarities to those reported in racehorses. This investigation aimed to consider the relationship between the magnitude of the asymmetries presented within the general equine population, and their previously reported directionality. Direct measurements of 15 bilateral traits (four facial and 11 limb) were captured from a mixed population of 100 horses and ponies. The pooled (whole) population was considered further as horse (withers height >148 cm) and ...
Liuti T, Dixon PM.The geometric morphometrics method (GMM) is a technique to study scale and shape relationships of structures using Cartesian geometric coordinates rather than linear, areal (of area), or volumetric variables. GMM has been of great value in many biological studies, but does not appear to have been used to examine equine skulls.In this exploratory study, twenty-nine normal equine heads of three different age groups: 16 years old (N = 10) were examined.Computed tomography (CT) bone window DICOM images were reconstructed into isosurfaces (3-dimensional contoured surfaces), onto which landm...
Mostafa MB, Abdelgalil AI, Farhat SF, Raw Z, Kubasiewicz LM.Working equids rely on sound, balanced hooves, but data describing the typical morphology of the legs and feet of working donkeys are currently lacking. To address this gap in knowledge, the front and hind feet of twenty healthy working donkeys were measured and compared. Hoof width, weight-bearing lengths, heel width, dorsal hoof wall length and lateral and medial heel length of the hoof wall were determined, as well as toe angle, heel angle, hoof pastern axis, coronary band angle and a measure of 'ground surface size'. Viewed from the ground surface of the foot, front feet were more rounded ...
Mostafa MB, Elemmawy YM.There is limited knowledge about causes of musculoskeletal injury in jumping Thoroughbred horses. The objective of this study was to describe the relationships between musculoskeletal disorders and linear and angular limb measurements acquired from photographs of horses with markers at specific reference points. The diagnosed musculoskeletal disorders in either fore or hind limbs were flexor tendonitis, suspensory ligaments desmitis, and osteoarthritis of the distal intertarsal and tarso-metatarsal and carpometacarpal joints. Lengths and angles in 17 clinically normal jumping Thoroughbred hors...
Zedda M, Sathe V, Chakraborty P, Palombo MR, Farina V.The microstructural features of the tissue of long bones subjected to different biomechanical stresses could be a helpful tool for a better understanding of locomotor behavior in extant and extinct mammals, including equids. However, few researches have attempted to describe the bone tissue of extinct horses. In our study, we analyze and compare the histomorphometric features of the bone tissue in extant modern horses, Equus caballus, and Equus namadicus, a Pleistocene Indian extinct wild horse. The number, position, and size of the osteons and Haversian canals of the bone tissue, classifiable...
Merkies K, Paraschou G, McGreevy PD.Horses and donkeys belong to the genus Equus, but important differences exist between the species, many of which affect their management and welfare. This study compared skull morphology between horses and donkeys. Horse ( = 14) and donkey ( = 16) heads were obtained post-mortem, sectioned sagittally close to the midline, and photographed for subsequent measurement of various skull structures. Skull, cranial, nasal, and profile indices were calculated for topographical comparisons between the species. The olfactory bulb area (OBA), OB pitch (the angle between the hard palate and the OB axis), ...
Rubessa M, Feugang JM, Kandel ME, Schreiber S, Hessee J, Salerno F, Meyers S, Chu I, Popescu G, Wheeler MB.The capacity for microscopic evaluation of sperm is useful for assisted reproductive technologies (ART), because this can allow for specific selection of sperm cells for in vitro fertilization (IVF). The objective of this study was to analyze the same sperm samples using two high-resolution methods: spatial light interference microscopy (SLIM) and atomic force microscopy (AFM) to determine if with one method there was more timely and different information obtained than the other. To address this objective, there was evaluation of sperm populations from boars and stallions. To the best of our k...
Giontella A, Sarti FM, Biggio GP, Giovannini S, Cherchi R, Pieramati C, Silvestrelli M.The purpose of this study was to estimate the heritability and genetic correlations of four biometric measurements and an overall score (OS) in the Sardinian Anglo-Arab horse (SAA); moreover, the effect of inbreeding on these traits was investigated. A dataset with 43,624 horses (27,052 females and 16,572 males) was provided by the Agricultural Research Agency of Sardinia (AGRIS). Cannon bone circumference (BC), chest girth (CG), shoulder length (SL), and withers height (WH) were measured on 6033 SAA horses born in Sardinia between 1967 and 2005; beside the measurements, an overall score (OS) ...
Salamanca-Carreño A, Jordana J, Crosby-Granados RA, Bentez-Molano J, Parés-Casanova PM.This is the first morphological comparative study between local horses and mules from Arauca, Colombia. It was realized to compare morphological traits between both species by analysing 15 adult mules (7 males and 8 females) and 150 adult horses (137 males and 13 females), with an age interval from 2 to 22 years. Data consisted of 24 different body quantitative traits which can explain the body conformation: thoracic circumference, body length (BL), thoracic depth and width, withers height (WH), sternum height, shoulders width, chest width, forelimb cannon perimeter and length, head length and...
Valberg SJ, Borer Matsui AK, Firshman AM, Bookbinder L, Katzman SA, Finno CJ.Although muscle mass strongly influences performance, there is currently no effective means to measure the 3-dimensional muscle mass of horses. We evaluated a 3-dimensional (3D) scanning methodology for its ability to quantify torso and hindquarter volumes as a proxy for regional muscle mass in horses. Determine the repeatability of 3D scanning volume (V) measurements and their correlation to body weight, estimated body volume and muscle/fat ultrasound (US) depth. Handheld 3D photonic scans were performed on 16 Quarter Horses of known body weight 56 days apart (n = 32 scans) with each scan per...
Cash CM, Fitzgerald DM, Spence RJ, de Laat MA.Equine metabolic syndrome (EMS) describes a group of risk factors, including obesity and insulin dysregulation (hyperinsulinemia and/or insulin resistance), that can lead to the development of the debilitating hoof disease laminitis. Although the underlying mechanisms of EMS are not fully understood, a genetic component has been reported, and an 11 guanine polymorphism located at the FAM174A gene has been identified as a risk locus for the syndrome in Arabian horses. To examine associations between the FAM174A risk allele and the clinical signs of EMS, the allele was examined in an Australian ...
Parés-Casanova PM, Salamanca-Carreño A, Crosby-Granados RA, Bentez-Molano J.Skull size and shape have been widely used to study domestic animal populations and breeds. Although several techniques have been proposed to quantify cranial form, few attempts have been made to compare the results obtained by different techniques. While linear morphometrics has traditionally been used in breed characterization, recent advances in geometric morphometrics have created new techniques for specifically quantifying shape and size. The objective of this study was to compare two morphometric methods for their ability to describe external morphology. For this purpose, 20 skull specim...
Medeiros BR, Garbade P, Seixas L, Peripolli V, McManus C.The aim of this study was to evaluate genetic parameters for subjective scores given at the Brazilian Sport Horse (BSH) Stallion Approval by estimating heritability (h) for morphological, gait, and jumping traits and genetic correlations (γ) among the functional ones and by verifying selection feasibility. The analysis included 1179 complete evaluations from 294 horses, by 4.26 ± 0.96 judges. Each trait was evaluated using mixed models in SAS® v9.2, considering the individual as a random effect. Variance components and genetic parameters were obtained by single and two-trait animal mode...
Fowler AL, Pyles MB, Bill VT, Hayes SH, Harris PA, Lawrence LM.Equine obesity is increasing in prevalence, and weight loss diets are frequently recommended for these horses. However, there are also management situations in which horses are deemed to be too thin. To monitor the efficacy of weight change programs, estimates of body fat are often made. There are several systems available to estimate body fat, and there are benefits and challenges to using each method. The objective of this study was to compare four different methods of estimating body fat in Thoroughbred horses. In 14 mature Thoroughbred horses, relationships among body condition score (BCS)...
Pasolini MP, Spinella G, Del Prete C, Valentini S, Coluccia P, Auletta L, Greco M, Meomartino L.Ultrasonography (US) is the recommended imaging technique to evaluate jugular veins. This prospective randomized clinical study was designed to collect a series of B-mode US measurements of manually distended jugular veins in healthy Italian Standardbreds and to find possible correlations between ultrasound measurements and animal morphometric characteristics. Forty-two horses, eight males and 34 females (range 3-22 years; bodyweight 494.4 ± 41.7 kg), were included in the study. The diameters and wall thicknesses of both jugular veins were measured at three different sites of the neck...
Legere RM, Taylor DR, Davis JL, Bello K, Parker C, Judd RL, Wooldridge AA.Chronic insulin dysregulation is challenging to manage with pharmaceuticals in horses. Pioglitazone improves insulin sensitivity in humans, and the pharmacokinetics of pioglitazone have been evaluated in horses. The objectives of this study were to assess the pharmacodynamic effects of oral pioglitazone on morphometric parameters, hepatic enzyme activity and function, adipokines, and enteroinsular response to oral sugar. A prospective pilot study was performed using fifteen adult equids (8 ponies, 7 horses) to evaluate the effects of short-term pioglitazone administration (2 mg/kg PO q 24 hou...
Heck L, Sanchez-Villagra MR, Stange M.Much of the shape variation found in animals is based on allometry and heterochrony. Horses represent an excellent model to investigate patterns of size-shape variation among breeds that were intentionally bred for extreme small and large sizes. Methods: We tested whether ponies (wither height < 148 cm) have a diverging size-shape relationship in skull shape as compared to regular-sized horse breeds (wither height > 148 cm, here-after called horses) during ontogenetic growth. We used a dataset of 194 specimens from 25 horse and 13 pony breeds, two of which are miniature breeds (wither height <...
MacLaren JA, McHorse BK.The absence of preserved soft tissues in the fossil record is frequently a hindrance for palaeontologists wishing to investigate morphological shifts in key skeletal systems, such as the limbs. Understanding the soft tissue composition of modern species can aid in understanding changes in musculoskeletal features through evolution, including those pertaining to locomotion. Establishing anatomical differences in soft tissues utilising an extant phylogenetic bracket can, in turn, assist in interpreting morphological changes in hard tissues and modelling musculoskeletal movements during evolution...
Silva ESM, Leite RO, Maciel LFS, Francia CCDA, Padovani CR, Oliveira-Filho JP, Meira C.Aiming to investigate the effects of different hormonal protocols on the endometrium morphometry of anestrous mares, 26 animals were assigned to four different treatment groups: (1) EB2.5LAP4: single dose of 2.5 mg of estradiol benzoate (EB); (2) EB5LAP4: 5 mg of EB in 2 consecutive days; (3) EB10LAP4: 10 mg of EB in three consecutive days, considering that all EB-treated groups received a single dose of 1,500 mg of long-acting progesterone (LA P4) after the single/last EB dose; and (4) LAP4: only 1,500 mg of LA P4. Results were also compared with those found in cyclic mares (control grou...
Gómez-Torres FA, Ballesteros-Acuña LE, Ruíz-Sauri A.The cardiac nodes are the source of the electrical impulse that is transmitted to the heart, the aim of this work is study the histological and morphometric characteristics of the different components of the sinus and atrioventricular nodes in horses and dogs that help to know the physiopathology of these nodes. A group of ten horse hearts and five dog hearts were used. The region of the sinus and atrioventricular nodes was sectioned serially, and the block of tissue removed for study. The samples were assessed using a morphometric analysis with the Image-Pro Plus 7.1 software and the acquisit...
Prado Silva RH, Carneiro de Rezende AS, Ferreira WM, Bastianetto E, Mello MM, Pereira de Abreu A, Farinelli F, Colares de Araújo Moreira D....Weanlings undergo rapid body development in the first year of life and, in this period, are more susceptible to helminth infection that can impair their growth. The objective of this study was to compare the apparent digestibility of nutrients, blood parameters, and body development of deworming and not deworming weanlings. Fourteen Mangalarga Marchador weanling colts, on a farm in Northern Minas Gerais, Brazil, were divided into two groups: dewormed (D) and not dewormed (ND) groups. The weanlings were kept separately for 3 months in two pastures of Cynodon nlemfuensis cv. African Star Grass....
Di Filippo PA, Dias Meireles MA, Ribeiro LMF, de Lannes ST, Meireles NFT, Viana IS, Hokamura HK.In this study, the effect of early exercise, age, body weight (BW), and growth on the articular cartilage and subchondral bones of the tarsocrural joints was evaluated in 40 young Mangalarga Marchador horses allowed free choice exercise in pasture. Twenty of the horses had additional controlled exercise 3 days per week from a mean age of 30 ± 20 days until 36 months. The training program consisted of an increasing number of 15-minute gallop sprints in an oval paddock with a concrete floor covered by a thick layer of sand. BW, withers height (WH), and neck circumference were measured and bo...
Quaresma M, Bacellar D, Leiva B, Silva SR.The use of the measurement of heart girth (HG), in locations where a scale is not available, with the application of weight estimation formulas or special weight tapes, is well established as a practical and accurate way to estimate the live weight (LW). Although several studies were performed to correlate donkey body measurements and LW, none of these was done in the large frame European donkey breeds. When using smaller frame breeds formulas, the tendency was to underestimate the live weight of larger frame breeds. The sample used in this study consisted of 65 Miranda breed donkeys, with age...
Catalano DN, Coleman RJ, Hathaway MR, Neu AE, Wagner EL, Tyler PJ, McCue ME, Martinson KL.Adding breed type, height, and neck circumference to body length and girth circumference improves bodyweight (BW) estimation in different breeds of horses; however, equations have not been developed for all breed types. The objectives were to develop BW estimation equations for Miniature, saddle-type, and Thoroughbred horses using morphometric measurements. Measurements were collected on adult (≥3 years, nonpregnant) saddle-type (n = 209), adult (n = 249) and juvenile (<3 years, n = 61) Miniatures, and adult Thoroughbreds (n = 100). Personnel determined body condition score (BCS), m...
Köhler L, Schulz-Kornas E, Vervuert I, Gittel C, Winter K, Berner D, Gerlach K.Despite clinical importance and frequent occurrence of sinus disease, little is known about the size of paranasal sinuses and their communication in ponies and small horses. To examine the shape and volume of the paranasal sinuses and evaluate the sinonasal communication, three-dimensional (3D) reconstructions of computed tomography (CT) datasets of 12 healthy adult Shetland ponies were performed and analysed. Linear measurements of head length and width were taken. Using semi-automatic segmentation, 3D-models of all sinus compartments were created. Volumetric measurement of the seven sinus co...
Mostafa MB, Abdelgalil AI, Farhat SF, Raw Z, Kubasiewicz LM.Working equids rely on sound, balanced hooves, but data describing the typical morphology of the legs and feet of working donkeys are currently lacking. To address this gap in knowledge, the front and hind feet of twenty healthy working donkeys were measured and compared. Hoof width, weight-bearing lengths, heel width, dorsal hoof wall length and lateral and medial heel length of the hoof wall were determined, as well as toe angle, heel angle, hoof pastern axis, coronary band angle and a measure of 'ground surface size'. Viewed from the ground surface of the foot, front feet were more rounded ...
Weller R, Pfau T, Babbage D, Brittin E, May SA, Wilson AM.The importance of a reliable method for conformation studies is generally acknowledged, but there are only limited data on the accuracy and precision of current assessment methods. Objective: To assess (1) the accuracy and repeatability of marker placement, (2) influence of stance of the horse on conformational parameters, (3) practicality of a computerised motion analysis system and (4) to compare the computerised motion analysis system to photographic systems of assessment. Methods: Twenty-eight reflective markers placed over anatomical landmarks were located in 3D using a computerised motio...
Ross D, Marcot JD, Betteridge KJ, Nascone-Yoder N, Bailey CS, Sears KE.Tetrapod limb development has been studied extensively for decades, yet the strength and role of developmental constraints in this process remains unresolved. Mammals exhibit a particularly wide array of limb morphologies associated with various locomotion modes and behaviors, providing a useful system for identifying periods of developmental constraint and conserved developmental mechanisms or morphologies. In this study, landmark-based geometric morphometrics are used to investigate levels and patterns of morphological diversity (disparity) among the developing forelimbs of four mammals with...
McEwen SA, Hulland TJ.Thirteen horses with histories of exertional rhabdomyolysis were exercised for 20 minutes to induce clinical signs of lameness, elevated serum creatine kinase (CK), and aspartate aminotransferase (AST) activities and skeletal muscle morphologic lesions. The clinical signs exhibited by affected horses included trembling, sweating, increased rate of respiration, and restricted limb movement. Serum CK reached maximal activity between 4 and 8 hours after the exercise period and serum AST activity peaked between 24 and 48 hours. Histologically, the skeletal muscle lesions in muscle biopsies 24 hour...
Martin-Gimenez T, de Blas I, Aguilera-Tejero E, Diez de Castro E, Aguirre-Pascasio CN.Equine metabolic syndrome (EMS) can be diagnosed by hormonal measurements; however, it would be important to find simpler measurements that allow easy identification of affected or at risk individuals. In horses, the dorsal neck region is one of the most frequent anatomical sites for fat deposition and neck obesity has been linked to EMS. The aim of this study was to evaluate the association of hormonal markers of obesity (leptin) and insulin resistance (insulin) with morphometric and ultrasonographic neck measurements in Andalusian horses. Plasma leptin and insulin concentrations were measure...
Thomason JJ, McClinchey HL, Faramarzi B, Jofriet JC.The horse's hoof is structurally modified for its mechanical functions, but studying the functional design of internal structures is hampered by the external keratinous capsule. Finite-element analysis offers one method for evaluating mechanical function of components within the capsule, such as the laminar junction. This is the epidermodermal connection that binds the hoof wall strongly to the distal phalanx. Primary epidermal laminae (PEL), projecting inward from the wall, vary in morphology and are remodeled despite being keratinous. The aim of this study is to investigate the suggestion th...
Wilson GH, McDonald K, O'Connell MJ.Research has highlighted a high frequency of skeletal asymmetries in horses. In addition, research into hoof asymmetries has shown that within a bilateral pair, the hoof with the smaller angle is often subjected to greater loading. There has been limited attention paid to understanding compensatory mechanisms for skeletal asymmetries in the horse; the dynamic structure of the hoof could potentially be acting in a compensatory capacity. Objective: To investigate the relationship between morphometry of forelimb segments and hoof spread and their incidence of asymmetry. Methods: Ten bilateral mea...
Liuti T, Reardon R, Dixon PM.Disorders affecting the equine maxillary cheek teeth and paranasal sinuses are relatively common, but limited objective information is available on the dimensions and relationships of these structures in horses of different ages. The aims of this study were to assess age-related changes in the positioning and anatomical relationships of the individual maxillary cheek teeth with the infraorbital canal and maxillary septum and the volumes of the individual sinus compartments. CT and gross examination were performed on 60 normal equine cadaver heads that were aged by their dentition. The intrasin...
Severa L, Máchal L, Svábová L, Mamica O.This study quantified and evaluated the variability of sperm head shape for 10 different stallions. Sperm head shape characteristics including sperm head length to width ratio, position of the center of gravity, curvature, and degree of roundness were assessed and analysed from images using elliptic Fourier descriptors and inverse Fourier transformation. The first four principal components accounted for 88.46-92.33% of the total variance and provided a good summary of the overall data. In the case of the ejaculate with defective sperm heads the components accounted for 97.35-98.21% of variatio...
Johnston C, Holm KR, Erichsen C, Eksell P, Drevemo S.Clinical history and examination are important features in diagnosis of equine back dysfunction. However, interpretation is subjective and therefore may vary substantially. Objective: To establish a clinical tool to objectively evaluate the function of the equine back, in the form of a database on the kinematics of the back at the walk and trot in fully functioning riding horses. Methods: Thirty-three fully functioning riding horses walked and trotted on a treadmill. Morphometrics and kinematics were tested for correlations to age, height, weight and stride length, and differences between gend...
Firth EC, Rogers CW, Anderson BH.To determine the weight, volume, density and cross-sectional area (CSA) of the digital flexor tendons, common digital extensor tendon (CDET) and suspensory ligament (SL) of the forelimb of young Thoroughbred horses in early training, and to assess the response to a training programme of known parameters of superficial digital flexor tendon (SDFT) tissue at mid-metacarpal level. Methods: The tendons of seven 2-year-old Thoroughbred horses in training were inspected, transected into segments of known length, and compared with those from seven untrained horses matched for age, sex and breed. The ...
Zedda M, Sathe V, Chakraborty P, Palombo MR, Farina V.The microstructural features of the tissue of long bones subjected to different biomechanical stresses could be a helpful tool for a better understanding of locomotor behavior in extant and extinct mammals, including equids. However, few researches have attempted to describe the bone tissue of extinct horses. In our study, we analyze and compare the histomorphometric features of the bone tissue in extant modern horses, Equus caballus, and Equus namadicus, a Pleistocene Indian extinct wild horse. The number, position, and size of the osteons and Haversian canals of the bone tissue, classifiable...
Rovira S, Muñoz A, Rodilla V.Scaling in biology is usually allometric, and therefore, the size of the heart may be expressed as a power function of body weight (BW). The present research analyses the echocardiographic measurements in 68 healthy Spanish foals weighed between 70 and 347kg in order to determine the correct scaling exponent for the allometric equation. The echocardiographic parameters measured were: left ventricular internal dimensions (LVID), free wall thickness (LVFWT), interventricular septum thickness (IVST) at systole (s) and diastole (d), EPSS (distance between the point E of the mitral valve and the in...
Rivero JL, Galisteo AM, Agüera E, Miró F.Muscle biopsies were taken from the middle gluteal muscle of 143 untrained horses (83 Andalusians [AN] and 60 Arabians [AR]) ranging from 10 days to 24 years old. The horses were separated according to breed and sex and allotted to five age groups: A, 0 to three months; B, yearlings; C, two to three years; D, five to 10 years; and E, 11 to 24 years. There was an increase in the percentage of type I fibres (about 100 per cent) as well as a decrease in the percentage of type IIB fibres (AN, 50 per cent; AR, 40 per cent) over the five age groups. The percentage of type IIA fibres rose significant...
Ducharme NG, Hackett RP, Fubini SL, Erb HN.Twenty Thoroughbred and Standardbred horses underwent endoscopic evaluation of arytenoid cartilage movement twice within 1 week. Each time, a flexible endoscope was passed without sedation through the right nostril and the left nostril, and through the right nostril 5 minutes after administration of xylazine hydrochloride (0.55 mg/kg or 1.1 mg/kg intravenously). Laryngeal cartilage movement was videorecorded. All videotaped images were reviewed by three veterinarians and subjectively placed in one of four grades. The intraobserver agreement rate varied from 52.6% for examination under sedation...
Richardson JD, Cripps PJ, Lane JG.Dental features are commonly expected to provide an accurate estimate of a horse's age. In this study the dentition of 434 thoroughbreds was photographed and the individual dental features documented, the true age of all the horses was known. For each dental feature the correlation with true age was determined. The eruption of the incisor teeth was the most consistent feature but it was not totally reliable. The presence of a hook on the upper corner incisor and Galvayne's groove proved to be of no value when estimating age and, of the attritional features studied, the dental star showed the h...
Moraes JR, Facco GG, Moraes FR, Engracia Filho JR, Miyazato LG, Beretta DC.An inflammatory process was induced by intratendinous injection of bacterial collagenase into the superficial digital flexor tendon (SDFT) of the left thoracic limb of 10 horses. One week later, the tendons in five of the horses (group 1) were treated with glycosaminoglycan polysulphate (GAGPS), and the tendons of the other five (group 2) were treated with saline solution. The horses were euthanased 150 days after the collagenase injections, and samples of the SDFTs were frozen at -14 degrees C, sectioned at 5 to 7 mum longitudinally and transversely, and stained by the picrosirius red method....
Kayar SR, Hoppeler H, Armstrong RB, Laughlin MH, Lindstedt SL, Jones JH, Conley KR, Taylor CR.The mean minimal capillary transit time was estimated in muscles of various animals using a combination of physiological and morphometric methods. Radioactive microspheres were injected intravascularly in various animals running on a treadmill at maximum oxygen consumption rate (VO2,max) to label blood flow to individual muscles. The muscles were then removed and preserved by standard methods for electron microscopy. The volume density of mitochondria was measured to assess muscle oxidative capacity. Capillary densities in muscle cross-sections, capillary diameters and tortuosities were incorp...
Riemersma DJ, De Bruyn P.The cross-sectional area, collagen content, dry weight as a percentage of the wet weight and the tendon fibre percentage of the cross-sectional area of the equine hindlimb were determined in the superficial and deep digital flexor tendons and the suspensory ligament at 10, 12 and six sites between tarsus and insertion respectively. The values of each of the four parameters varied between different sites in the same tendon, between different tendons within a horse and between analogous tendons of different horses. Within a tendon the cross-sectional area was inversely proportional to the collag...
Roland E, Stover SM, Hull ML, Dorsch K.To define a 3-dimensional (3-D) coordinate system with clear definitions of origins and axes relative to hoof anatomic features and determine whether solar surfaces of Thoroughbred racehorse hooves have geometric asymmetry in the mediolateral and dorsopalmar directions. Methods: Left forelimb hooves from 20 Thoroughbred racehorse cadavers. Methods: A right-handed 3-D coordinate axes system centered on the collateral sulci was defined for the left front hoof. Orthogonal distances of anatomic features from the dorsopalmar axis and the plane coincident with the ground were measured and compared b...
Morgan SJ, Stromberg PC, Storts RW, Sowa BA, Lay JC.Histological and morphometric evaluation of equine cranial mesenteric arteries was performed on 239 and 89 arteries, respectively. Histological examination revealed that thrombosis and the severity of inflammation varied on a seasonal basis and were directly associated with larval presence. Intimal and adventitial fibrosis were generally of greater severity than medial fibrosis. Fibrosis of the vasa vasorum was less frequent than fibrosis of the artery itself. Morphometry revealed a significant increase in intimal, adventitial and, to a lesser extent, medial area in affected as compared with n...
Ribeiro AA, Davis C, Gabella G.The superior (cranial) cervical ganglion was investigated by light microscopy in adult rats, capybaras (Hydrochaeris hydrochaeris) and horses. The ganglia were vascularly perfused, embedded in resin and cut into semi-thin sections. An unbiased stereological procedure (disector method) was used to estimate ganglion neuron size, total number of ganglion neurons, neuronal density. The volume of the ganglion was 0.5 mm3 in rats, 226 mm3 in capybaras and 412 mm3 in horses. The total number of neurons per ganglion was 18,800, 1,520,000 and 3,390,000 and the number of neurons per cubic millimetre was...
Russo D, Bombardi C, Castellani G, Chiocchetti R.Spinal ganglion (SG) neurons have been widely described in rodents, and classified according to various criteria. On the basis of such studies, many features of rodent SG neurons have become benchmarks to classify these cells. However, these traits cannot be confirmed in all other species. In the present study, horse SG neurons were morphometrically and neurochemically characterized by detecting the neuronal markers calcitonin gene-related peptide (CGRP), substance P (SP), neuronal nitric oxide synthase (nNOS) and isolectin B4 (IB4) from Griffonia simplicifolia. Moreover, spinal cord staining ...
Komosa M, Frackowiak H, Purzyc H, Wojnowska M, Gramacki A, Gramacki J.The study included 249 horses belonging to 3 horse breeds. Konik horses, comprising the first group, is an example of a breed similar to the extinct Tarpan. In our study, these horses were taken to be a primitive anatomical model of the horse body. The other groups comprised the Polish Half-bred horse and Thoroughbred horse. The biometric characteristics of the horses were compared based on 24 indices. The aim of the paper was to find a reduced set of indices that can be used to determine group membership of the horses. To do this, we used statistical methods to find the most important indices...
Galisteo AM, Cano MR, Morales JL, Vivo J, Miró F.The influence of speed and height at the withers on some biokinematic stride parameters (linear, temporal and angular) was measured in 15 Spanish Thoroughbreds (Andalusian Purebred) trotted hand-led along a track; analysis was made of the correlation between speed and height at the withers and of some biokinematic parameters of equine locomotion. Both height at the withers and speed were positively and significantly correlated to the linear parameters examined. Temporal parameters did not reveal a significant correlation with the height at the withers. The correlations with the angular paramet...
Bruynsteen L, Moons CP, Janssens GP, Harris PA, Vandevelde K, Lefère L, Duchateau L, Hesta M.Due to the high prevalence of obesity in some horses and ponies (especially in the leisure horse sector), effective and safe weight loss strategies are required. The present study evaluated the effect of two different energy restriction rates on physical, morphometric and welfare parameters in 18 obese (body condition score [BCS] 7-9/9) Shetland geldings. The trial was divided into three periods: (1) a 4 week adaptation period, during which the maintenance energy intakes to maintain a stable obese bodyweight were determined (100% MERob); (2) a 16.5-week weight loss period during which the poni...
Guo X, Sugita S.Topography of ganglion cells in the retina of the horse (Thoroughbred) was analyzed in the wholemount retina stained with cresyl violet, and a total number of ganglion cells were estimated. Sizes of ganglion cells were also measured and size spectra were analysed. The main results showed that: (1) a common point in 4 wholemount retinae, based on cell densities and retinal locations, was that a retina could be divided into 5 regions, namely visual streak, nasal, temporal, dorsal and ventral region to the visual streak. A maximum cell density of 4,000 cells/mm2 was found in the visual streak. An...
Ritruechai P, Weller R, Wakeling JM.The longissimus dorsi is the largest muscle in the equine back and plays an important role in locomotor ability and performance in the horse. In vivo studies suggest that the mechanical function varies between different muscle segments, in part determined by anatomy. It is possible therefore that variations in function reflect variations in the anatomy of the longissimus dorsi along its length. Objective: To identify if there are regional variations in muscle architecture of the longissimus dorsi. Methods: Computed tomography scans were obtained from 8 cadaver backs to identify the cross-secti...
Dietzel J, Kuhrt H, Stahl T, Kacza J, Seeger J, Weber M, Uhlig A, Reichenbach A, Grosche A, Pannicke T.Borna disease (BD) is a fatal disorder of horses, often characterized by blindness. Although degeneration of retinal neurons has been demonstrated in a rat model, there are controversial data concerning whether a similar degeneration occurs in the retina of infected horses. To investigate whether BD may cause degeneration of photoreceptors and possibly of other neuronal cells at least at later stages of the disease, we performed a detailed quantitative morphologic study of retinal tissue from Borna-diseased horses. BD was diagnosed by detection of pathognomonic Joest-Degen inclusion bodies in ...
