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.
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...
Harrison GD, Duncan ID, Clayton MK.The age of onset of equine recurrent laryngeal neuropathy has not been ascertained, although the clinical condition of left laryngeal hemiplegia ("roaring") has been recognized for centuries. The purpose of this study was to evaluate the laryngeal muscles of draft horse foals for the presence of fiber-type grouping, indicating denervation and reinnervation, and to determine if histological evidence of recurrent laryngeal neuropathy was present. Abductor and adductor laryngeal muscles from the left and right sides were collected immediately after euthanasia from male draft horse foals, six less...
Savage CJ, Tidd LC, Melsen F, Jeffcott LB, Ostblom L.The histomorphometrical examination of a series of bone biopsies from the wing of ilium of foals and older horses is reported. Biopsies were obtained from 20 clinically normal horses, which had previously been infused with tetracycline intravenously twice at a 7 day interval at a dose rate of 10 to 15 mg kg-1. The horses were divided into 2 groups. Group 1 consisted of 10 foals (mean age: 4 +/- 1 months) which were biopsied at 3 different sites in the wing of ilium. Group 2 comprised 10 older horses (mean age: 91 +/- 63 months) which were biopsied from only one site in the left ilium. A system...
Mifune H, Suzuki S, Noda Y, Mohri S, Mochizuki K.In the pig, cattle and horse, the right and left atria and ventricles were examined by immunohistochemistry, and the right atrial and auricular cardiocytes were studied by transmission electron microscopy. Moreover, ANP-granules in the cardiocytes were analyzed by ultrastructural morphometry. Immunohistochemically, the most intensely ANP-reacted cardiocytes were localized in the right auricle, particularly more prominent in the pig and cattle than in the horse. Ultrastructurally, ANP-granules were located principally in the perinuclear region associated with the Golgi apparatus and throughout ...
Art T, Lekeux P.In order to study the in vitro mechanical properties of the equine trachea submitted to the compressive pressures observed in vivo, the pressure-volume relationship was determined in intra- and extra-thoracic tracheal segments taken post mortem from 29 healthy horses (one to 15 years old; 352 to 651 kg). At the same time, the cross-sectional lumen area (X-SA) at the mid-point of the segment was measured using a slit-lamp transillumination and photographic measurement by endoscopy. The tracheal specific compliance (Cs) as well as the relative changes in X-SA and in the sagittal and transverse d...
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...
Young DR, Richardson DW, Markel MD, Nunamaker DM.The third carpal bone (C3) was collected from both forelimbs of 27 Thoroughbreds. On the basis of age, training, and history, specimens were assigned to 1 of 5 groups: yearling, untrained horses (group 1, n = 4); 2- to 3-year-old, untrained horses (group 2, n = 7); trained 2-year-old horses (group 3, n = 6); trained 3-year-old horses (group 4, n = 6); and 3-year-old, trained horses with carpal pathologic features (group 5, n = 4). A transverse section of subchondral bone 5-mm thick was cut in a precise fashion 10 mm below the proximal articular surface of all specimens. After high-detail radio...
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...
Vörös K, Holmes JR, Gibbs C.This study was designed to evaluate the accuracy of two-dimensional echocardiography (2DE) in determining the left ventricular volume (LVV) of the horse in vitro. After examining the shape of the left ventricular silicon rubber casts of four equine hearts, two modified Simpson's rule methods (Model A and Model B) as combinations of conical shapes and one biplane area-length method as a single cone (Model C) were chosen for volume calculations. One long axis and three short axis planes were used for linear and area 2DE measurements, respectively. The ventricular length (L) was calculated from t...
Bertone AL, Cockerell GL, Lee RE, Stashak TS.Light microscopy, morphometry, and scanning electron microscopy were used to examine the mucosal morphologic features of 7 intestinal specimens (3 from the small intestine; 4 from the large intestine) from each of 8 horses 1 year after sham operation (group 1; n = 3) or extensive large-colon resection (group 2; n = 5). Qualitative light microscopic examination did not reveal differences between groups, but morphometry revealed significantly (P less than 0.05) greater intercrypt area and distance in horses with colon resection and this was most pronounced in the cecum and remaining right ventra...
Bertone AL, Stashak TS, Smith FW, Norrdin RW.In nine horses (18 forelimbs), a 3 cm section of superficial digital flexor tendon was removed and the tendons were repaired with immobilization for 6 weeks and (1) no suture (n = 6); (2) a double locking loop tenorrhaphy with carbon fiber (n = 6); or (3) a double locking loop tenorrhaphy with size 2 nylon suture (n = 6). Clinical assessment, gross evaluation, morphometry, histology, and mechanical testing were performed on two limbs from each treatment group at weeks 6, 12, and 24. At weeks 6 and 12, the unsutured tissue was less mature than the tissue sutured with nylon. By week 24, the carb...
Holmström M, Magnusson LE, Philipsson J.The variation in conformation of 356 Swedish Warmblood horses is described, using a quantitative method of measuring horses. Thirty-three of the horses were élite dressage horses, 28 were élite showjumpers, 100 were riding school horses and 195 were unselected four-year-olds. Most horses had a long body form. The average height at the withers was 163.4 cm. Sixty per cent of the horses had a bench knee conformation, 50 per cent had a toe-in conformation of the forelimbs and 80 per cent had outwardly rotated hind limbs. The majority of these deviations were mild or moderate. Conformation was i...
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. ...
Hermanson JW, Hurley KJ.The biceps brachii of horses is a complex muscle subdivided into two heads which may subserve distinct functions. The lateral head contains a large percentage of type I myofibers. This region is largely composed of short fibers (5-7 mm long) arranged in a pinnate fashion and heavily invested with connective tissue. The medial head contains fewer type I fibers and is composed of relatively longer myofibers (15-20 mm long), also arranged in a pinnate fashion but less heavily invested with connective tissue. It is hypothesized that the lateral muscle head of biceps brachii contributes to the post...
Jones RS, Lawrence TL, Veevers A, Cleave N, Hall J.Fifty-three horses, all but two of them over two years of age and varying in type, sex and liveweight (230 to 707 kg) were weighed and seven different body measurements were recorded in duplicate by a single operator. The best overall prediction of liveweight using an equation with two variables was found to be: liveweight (kg) = (umbilical girth [cm])1.78 X (length of body from tuber ischii to elbow [cm]0.97/3011). This equation had an adjusted R2 value of 94.9 per cent and was derived from the pooled data, because differences of sex, type and weight did not significantly affect the relations...
Ostblom L, Lund C, Melsen F.Twelve horses suffering from navicular bone disease were examined in a prospective, controlled histomorphometric study for six months. The objective was to compare the histology of navicular bones from untreated animals to those treated with the egg-bar shoeing technique. These data were compared to similar sections from three normal animals. The current investigation provided quantitative support to previous findings concerning clinical improvement. Detailed histology, changes in bone morphometry and pathophysiological reactions are discussed.
Constantinopol M, Jones JH, Weibel ER, Taylor CR, Lindholm A, Karas RH.Because the maximal rate of O2 consumption (VO2max) of the horse is 2.6 times larger than that of steers of equal size, we wondered whether their pulmonary gas exchanger is proportionately larger. Three Standardbred racehorses [body mass (Mb) = 447 kg] and three domestic steers (Mb = 474 kg) whose cardiovascular function at VO2max had been thoroughly studied (Jones et al. J. Appl. Physiol. 67: 862-870, 1989) were used to study their lungs by morphometry. The basic morphometric parameters were similar in both species. The nearly 2 times larger lung volumes of the horses caused the gas exchange ...
Bertone AL, Cockerell GL, Lee RE, Stashak TS.Light microscopy, morphometry and scanning electron microscopy (SEM) were used to examine the mucosal morphology of seven intestinal specimens (three from the small intestine and four from the large intestine) from two horses not subjected to surgery and three horses one year after sham-operation for colon resection. Qualitative and quantitative evaluation revealed similar morphology for all horses except that the unoperated horses had significantly (P < 0.05) fewer goblet cells in the crypts of the large intestine. In the small intestine, SEM demonstrated that villus shape varied and range...
Samuelson D, Smith P, Brooks D.The iridocorneal angle of the horse was anteriorly lined by a pectinate ligament, consisting of several layers of vertically oriented collagenous beams, that were interrupted by a network of extracellular spaces. The anterior chamber angle consisted mostly of a large uveal trabecular meshwork that was composed of widely-spaced, thick trabeculae. These trabeculae were attached in part posteriorly to extensions of the ciliary body musculature and anteriorly inserted into the prominent pectinate ligament. The corneoscleral trabecular meshwork was shaped hemiobovately and formed the external bound...
Wheeler SJ, Plummer JM.Transverse sections of the lateral palmar nerve from a group of horses free from neuromuscular disease were assessed quantitatively, with emphasis on differences in the fibre population related to age. Morphometric analysis of the population of myelinated and unmyelinated fibres was performed. Changes were identified, there being a loss of larger myelinated fibres in older horses. The relationship of myelin thickness to axon diameter and the unmyelinated fibre population did not alter with age. The lateral palmar nerve is suitable for biopsy and electrophysiological study in the horse, but age...
Bianchi M.In 13 horses from both sexes, between 5 months and 18 years of age, in good nutritional state, statistical evaluations of fat cell sizes were performed in 16 body regions. From direct and indirect measurements referred to the cell diameter and cell number in equivalent areas, carried out on sections from paraffin embedded material and on preparations of dissociated whole cells, it emerged that the adipose cells of the subserous fat of the abdominal floor are consistently the largest, whereas those of the orbital fat body and supraorbital fossa are the smallest. In the other regions the cells h...
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...
Kayar SR, Hoppeler H, Essen-Gustavsson B, Schwerzmann K.A morphometric analysis was performed on horse muscle tissue to quantify mitochondrial distribution relative to capillaries. Samples of M. vastus medialis, M. semitendinosus, M. masseter and M. cutaneus thoracicus were preserved in a glutaraldehyde fixative for electron microscopy, or frozen for biochemical and histochemical analysis. These four muscles varied from highly oxidative in type, consisting nearly completely of type I fibres, in masseter, to highly glycolytic, primarily type IIb fibres, in cutaneus. In all four muscles, mitochondria were found in highest volume density near capillar...
Machida N, Yasuda J, Too K, Kudo N.The obliteration processes of the ductus arteriosus of equine foetuses and newborn foals were studied morphometrically and histologically. The length, internal and external diameters and circumference of the ductus in equine foetuses increased progressively and linearly up to 310 days with advancing foetal age, but the values, especially the internal diameter, decreased from 320 to 330 days. After birth, the ductal measurements decreased gradually and ductal closure was found in three of 14 foals examined on the first day post partum, in two of six on the second day and in nine of nine on the ...
Machida N, Yasuda J, Too K.A morphometric study of hearts in 81 equine foetuses, ranging in age from 190 to 330 days of foetal age, and in 26 newborn foals is reported. The mean weight, external dimensions, ventricular wall thickness and circumference of the atrio-ventricular orifice were measured. Features of the main associated vessels of the heart were also recorded. All cardiac measurements of foetuses increased linearly throughout the latter half of pregnancy and were highly correlated with foetal age. This linear growth pattern was also found in the parameters of the associated arterial trunks. The ratio of the ri...
Mermod L, Hoppeler H, Kayar SR, Straub R, Weibel ER.Muscle samples were taken from the superficial part of the semitendinosus muscle of four standardbred horses to compare the effects of three different fixation procedures on fiber size and capillarity. Infiltration fixation in an extended position of the muscle was compared to immersion fixation and infiltration fixation in a flexed position of the limb. The capillary length density was used to estimate muscle capillarity. Infiltration fixation was found to be a viable alternative to perfusion fixation of muscles for morphometry of fiber size and capillary length density allowing muscle tissue...
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: (...
Leach D, Cymbaluk NF.Velocity-dependent changes in stride length and frequency were studied in 19 male foals, 6 to 8 months of age, and were related to body morphometrics. Eighteen distance and 8 angle measurements were digitized from 16-mm films of standing foals. The total mass and the percentage of total mass acting through the forelimbs were also recorded. Stride length and frequency data were extracted from 16-mm films of 239 strides of the walk, trot, and canter-gallop. Polynomial-regression analysis was used to determine the equation that best described the relationship between data of stride length or freq...
Valette JP, Barrey E, Jouglin M, Courouce A, Auvinet B, Flaux B.Morphometric measurements were taken from 41 French trotters of various ages and both sexes. Biopsy location was determined for the dorsal compartment as being one-third of the distance from the tuber sacrale to the tuber coxae and for the ventral compartment as being one-third of the distance from the tuber coxae to the caudal Cd1-Cd2 intervertebral joint. Ten horses were biopsied at these 2 sites at a sampling depth equal to half the total depth of the compartment as measured by ultrasonography. The percentage of slow and fast myosin heavy chain fibres was measured by using an immunoenzymati...
Machida N, Yasuda J, Too K.A morphometric study of hearts in 81 equine foetuses, ranging in age from 190 to 330 days of foetal age, and in 26 newborn foals is reported. The mean weight, external dimensions, ventricular wall thickness and circumference of the atrio-ventricular orifice were measured. Features of the main associated vessels of the heart were also recorded. All cardiac measurements of foetuses increased linearly throughout the latter half of pregnancy and were highly correlated with foetal age. This linear growth pattern was also found in the parameters of the associated arterial trunks. The ratio of the ri...
Tan JH, Nanbo Y, Oikawa M, Kiso Y, Sasaki F.To analyze the sex difference in 6 kinds of adenohypophyseal cells of Mongolian ponies and the effect of prepubertal orchidectomy on adenohypophyseal cells. Methods: Pituitary glands collected from 15 adult Mongolian ponies, 5 to 10 years old: 5 stallions, 5 mares, and 5 geldings, orchidectomized between the ages of 1 and 2 years. Methods: Morphologic comparison of 6 kinds of adenohypophyseal cells among mares, stallions, and geldings was done, using immunocytochemistry and morphometry. Results: A sex difference was evident in the percentage of somatotrophs, gonadotrophs (follicle-stimulating ...
Góss GC, Mozzaquatro FD, Vanhove R, Camargo LP, Döwich Pradella G, Leite CT, Gomes EM, Carneiro ALM, Heckler GF, Duarte CA.The physiological measurements of collateral ligaments of distal interphalangeal joint (CL-DIPJ) differ in the literature. The factors that influence these differences are not well described. The aims of this study are to compare CL-DIPJ sizes in equines with different withers height, as well as to correlate body weight and hoof size to the size of these ligaments. In total, 52 horses were used in the study. They were divided into two groups according to wither height: Group 1 (G1) - 21 animals with up to 147 cm - and group 2 (G2) - 21 animals with greater than 148 cm. CL-DIPJ was ultrasonog...
Peli A, Roccaro M.Catastrophic injuries in racehorses mostly involve the metacarpal region. Although many studies describe fractures of equine limbs, few examine the relationship between bone morphometrics and musculoskeletal problems in racing horses. And yet, according to the regulation of some Italian traditional races, the shin circumference represents a qualifying prerequisite for horses to be admitted to races. This study aims to evaluate the conformity of the shin circumference measurement in living animals and in post‑mortem examinations, in order to evaluate the forensic reliability of these measurem...
Pasicka E, Tarnawski K, Chrószcz A, Geringer de Oedenberg H.The study was carried out on 126 mares of the Polish Konik horse breed. Mares were bred under a stable system housing and they came from five leading conservation breeding centres. The mares were divided into three age groups: 3-5 years old, 6-9 years old and over 10 years old. Each animal was characterized using 40 morphometric measurements. Discriminant analysis proved the exterior differences of mares in terms of the analysed metric values. It was concluded that the morphotype of modern Polish Konik mares is statistically significantly influenced by the following traits: neck ventral len...
Belyaev RI, Kuznetsov AN, Prilepskaya NE.The vertebral column is a hallmark of vertebrates; it is the structural basis of their body and the locomotor apparatus in particular. Locomotion of any vertebrate animal in its typical habitat is directly associated with functional adaptations of its vertebrae. This study is the first large-scale analysis of mobility throughout the presacral region of the vertebral column covering a majority of extant odd-toed ungulates from 6 genera and 15 species. In this study, we used a previously developed osteometry-based method to calculate available range of motion. We quantified all three directions ...
Davies HM, Gale SM, Baker ID.The aim of this study was to determine if changes in the shape of the third metacarpal bone (MC3) during the first preparation for racing in young Thoroughbred racehorses could be measured radiographically. Lateral radiographs of each MC3 were taken when the horses commenced training, every 2 weeks for 10 weeks, and again at 6 months after the start of training. The width of the dorsal cortex (DC), palmar cortex (PC), and medulla (M) were measured at a position 2.5 cm distal to the nutrient foramen before the subject of each radiograph was identified. The following ratios were calculated: z = ...
Saey V, Ploeg M, Delesalle C, van Loon G, Gröne A, Ducatelle R, Duchateau L, Chiers K.Rupture of the aorta is much more common in Friesians compared with other breeds of horse. Rupture always occurs adjacent to the scar of the ligamentum arteriosum. Previous histological examination of ruptured aortic walls suggested the presence of an underlying connective tissue disorder. Therefore, the aim of the present study was to compare the structural characteristics of the tunica media of the mid-thoracic aorta, distant to the lesion, in warmblood and Friesian horses with and without thoracic aortic rupture. In unaffected Friesian horses, the thickness of the tunica media, as well as t...
Cavalleri JM, Metzger J, Hellige M, Lampe V, Stuckenschneider K, Tipold A, Beineke A, Becker K, Distl O, Feige K.Cerebellar abiotrophy (CA) is a rare but significant disease in Arabian horses caused by progressive death of the Purkinje cells resulting in cerebellar ataxia characterized by a typical head tremor, jerky head movements and lack of menace response. The specific role of magnetic resonance imaging (MRI) to support clinical diagnosis has been discussed. However, as yet MR imaging has only been described in one equine CA case. The role of MR morphometry in this regard is currently unknown. Due to the hereditary nature of the disease, genetic testing can support the diagnosis of CA. Therefore, the...
Dietrich J, Handschuh S, Steidl R, Böhler A, Forstenpointner G, Egerbacher M, Peham C, Schöpper H.As the longissimus dorsi muscle is the largest muscle in the equine back, it has great influence on the stability of the spine and facilitates proper locomotion. The longissimus muscle provides support to the saddle and rider and thereby influences performance in the horse. Muscular dysfunction has been associated with back disorders and decline of performance. In general, muscle function is determined by its specific intramuscular architecture. However, only limited three-dimensional metrical data are available for the inner organisation of the equine longissimus dorsi muscle. Therefore, we a...
Roth IT, Schielke B, Rensing M, Bernau M.To investigate differences in American Quarter Horses conformation suggesting specialization and subpopulations within the breed, a total of 45 horses were studied. These horses were classified according to their specific sport discipline: Western Pleasure (WPL, n = 15), Hunter under Saddle (HUS, n = 15), and Reining (RN, n = 15). Fifteen linear traits (comprising lengths, angles, and circumferences) were measured analogically and photometrically. Afterwards, 9 ratios and differences were calculated, so that a total of 24 traits were examined. The results showed significant differences between...
Müller V, Moraes BDSS, Carvalho IR, Wendt CG, Patten RD, Nogueira CEW.The aim of this study was to estimate the genetic parameters for the morphometric measurements of withers height (WH), thoracic circumference (TC) and cannon bone circumference (CBC) of Criollo horses, stratified for maternal and paternal effects. Statistical genetic design of factor crossings was used to evaluate the offspring of full siblings and half-siblings. Fifty stallions were selected (n = 50) who had been crossed with six mares each (n = 6), to provide 300 parental pairings in which two offspring were born per mare (n = 600). WH in females and TC in males were highly influenced ...
Lopes MS, Mendonça D, Rojer H, Cabral V, Bettencourt SX, da Câmara Machado A.The Terceira Pony is a horse indigenous to Terceira Island in the Azores. These horses were very important during the colonization of the island. Due to their very balanced proportions and correct gaits, and with an average withers height of 1.28 m, the Terceira Pony is often confused with a miniature pure-bred Lusitano. This population was officially recognized as the fourth Portuguese equine breed by the national authorities in January, 2014. The aim of this study was to analyze the morphology and the genetic diversity by means of microsatellite markers of this emerging horse breed. The biom...
Gmel AI, Brem G, Neuditschko M.Conformation traits are important selection criteria in equine breeding, as they describe the exterior aspects of the horse (height, joint angles, shape). However, the genetic architecture of conformation is not well understood, as data of these traits mainly consist of subjective evaluation scores. Here, we performed genome-wide association studies on two-dimensional shape data of Lipizzan horses. Based on this data, we identified significant quantitative trait loci (QTL) associated with cresty neck on equine chromosome (ECA)16 within the MAGI1 gene, and with type, hereby differentiating heav...
Heun F, Böing L, Theunert J, Gasse H.This basically anatomical study focuses on two items; firstly, the establishment of a system for the cartographic subdivision of the neopallium; secondly, the topographical correlation of extracranial landmarks and intracranial sites on the neopallium. Methods: The surface of the neopallium was subdivided into 15 sectors with reference to a newly introduced pattern of Primary Sulci. The topographical link between extracranial landmarks and certain intracranial sites (i.e. neopallium sectors) was elaborated by using a simple stereotactic device and a computer-assisted measurement device. Measur...
Bianchi M.In 13 horses from both sexes, between 5 months and 18 years of age, in good nutritional state, statistical evaluations of fat cell sizes were performed in 16 body regions. From direct and indirect measurements referred to the cell diameter and cell number in equivalent areas, carried out on sections from paraffin embedded material and on preparations of dissociated whole cells, it emerged that the adipose cells of the subserous fat of the abdominal floor are consistently the largest, whereas those of the orbital fat body and supraorbital fossa are the smallest. In the other regions the cells h...
Roelfstra L, Vlimant M, Betschart B, Pfister K, Diehl PA.A morphological study of the midgut and salivary glands of second and third instars of Gasterophilus intestinalis (De Geer) (Diptera: Oestridae) was conducted by light, scanning and transmission electron microscopy. The midgut is anteriorly delimited by a proventriculus, without caeca, and is composed of posterior foregut and anterior midgut tissue from which a double-layered peritrophic matrix is produced. The midgut can be divided into anterior, median and posterior regions on the basis of the structural and physiological variations of the columnar cells which occur along its length. Two oth...
López-Plana C, Sautet JY, Ruberte J, Sabaté D.Histochemical and morphometric parameters of the cricoarytenoideus lateralis muscle of the horse are presented. Using myosin ATPase staining after acid preincubation, 3 fibre types (I, IIA and IIC) were identified. Using NADH-TR staining, type I fibres showed high oxidative capacity, whereas type II fibres had high or low oxidative capacity. The type I to type II ratio was of 35:65. This ratio remained constant in the age range examined. Statistically significant (p < 0.01) differences were found in values for fibre size between groups of horses weighing more than 500 kg and less than 400 k...
Tinel JB, Veras MM, Waked D, Alonso MA, Fernandes CB.Mules are derived from crossing horse mares with a donkey, in which the interest is due to gentleness and ability to work and equestrian sports. As the placenta is responsible for fetal development and maturation, knowing its typical microstructure allows us to understand how fetomaternal interactions occur in this interspecific pregnancy. Thus, the study performed a comparative stereological evaluation of volumetric composition and fetomaternal contact surface in the uterine body (UB), gravid uterine horn (GUH), and nongravid uterine horn (NGUH) of Mangalarga Paulista mare's term allantochori...
Faramarzi B.Hoof health is a major concern of horse owners as well as the equine industry. However, many questions remain concerning regional variations of laminar junction and its potential to remodel. Objective: To examine regional variations in the morphology of the laminar junction and thickness of the hoof wall in Thoroughbred horses. Methods: The forefeet of 25 Thoroughbred cadavers were examined. Each hoof was divided into 20 blocks through 4 proximodistal slices (below the coronary band, each 1 cm apart) and 5 circumferential positions (toe, medial and lateral quarters and heels). In each block, 2...
Trachsel DS, Giraudet A, Maso D, Hervé G, Hauri DD, Barrey E, Robert C.The heart's physiological adaptation to aerobic training leads to an increase in heart chamber size, and is referred to as the Athlete's heart. However, heart dimensions are also related to body weight (BWT), body size, growth and (in some species) breed. There are few published data on the relationships between heart dimensions and growth or aerobic training in Arabian and Arabian-related endurance horses. Therefore the objective of the present study was to describe the influence of body dimensions (body length (BL), thoracic circumference (TC), withers height (WH)), BWT, age, gender, breed (...
Lancaster LS, Bowker RM, Mauer WA.Density and morphologic features of hoof wall tubules in horses' hooves are described. The sample population consisted of hooves (n=12) from both live and deceased adult horses. Full wall thicknesses of the hoof wall were prepared histologically from sites at the toe, medial quarter and lateral quarter. In defined areas, tubules were counted, and density was calculated across the three histologically defined areas of the stratum externum, stratum medium and stratum internum along with the descriptive morphologic features of the tubules. Morphologically, distinct zones were demarcated by varyin...
Salamanca-Carreño A, Parés-Casanova PM, Rangel-Pachón DE, Bentez-Molano J, Vélez-Terranova OM.The aim of this research was to determine if the division between the cervical, dorsal, and croup profiles (three regions commonly assessed for descriptive profile purposes) has a modular basis as well as a morphological integration. For this, a total of 135 digital photographs were obtained, in a lateral view, of adult horses (14 females and 121 geldings; age range: 2-20 years), of the Araucanian breed, an equine population typical of the flooded savannah of Arauca, NE Colombia. From each image, 25 reference points (semi-landmarks) were obtained at the dorsal level of the neck, back, and crou...
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...
Davies HM.The relationships were explored between measurements of bone quality, size (quantity) and shape, and strain data collected during treadmill exercise at 4 and 12 m/s from the third metacarpal bones of 6 yearling and 6 mature Thoroughbred racehorses. Peak strains in yearling and mature Thoroughbred horses during exercise were related to the size and shape of the third metacarpal bone. The peak strains were significantly lower in horses with a greater cross-sectional area of bone and with a greater proportion of the bone in the dorsal cortex. There was no consistent relationship between peak stra...
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...
Evans TJ, Ganjam VK, Miller MA, Niswender KD, Krause WJ, Youngquist RS.Endometrial periglandular fibrosis (EPF) has been proposed as a possible aetiology for equine embryonic and fetal loss. However, the pathophysiology of EPF is not well understood. Angiotensin-converting enzyme (ACE) is found in macrophages, endothelium (during angiogenesis) and myofibroblasts at sites of fibrosis in the heart, kidneys, liver and skin in several species. An increase in local tissue ACE-binding activity appears to be a critical event in the initiation and progression of fibrosis in these tissues. The aim of this study was to investigate the correlation between ACE activity in th...
Bertram TA.Differences in neutrophil morphology between various species of domestic animals are evident when morphometric techniques are used. Morphometric analysis can be coupled with functional assays of degranulation to demonstrate changes in granule volume after neutrophil activation (Bertram and Jensen, 1984). Morphometric and functional analysis of the neutrophil can also be used to evaluate the response of neutrophils to infectious agents (Coignoul et al., 1984a). Comparison of these assays between animal species may provide insight into the susceptibility of animals to various microbial pathogens...
Herbig LE, Eule JC.The aim of this study was to determine the central corneal thickness (CCT) of healthy equine eyes with high-frequency ultrasound (HF) and ultrasound biomicroscopy (UBM) and to measure the axial dimensions with B-mode ultrasound. Additionally, the influence of the age on the measured dimensions of the globe was analyzed. Methods: Fifty warm blood horses (mean age 23.0 ± 21.12 months) were divided into 3 age groups (group 1: 0-6 months; group 2: ≥7-30 months; and group 3: ≥31-78 months). Methods: Corneal measurements were performed with a 22-MHz and a 50-MHz transducer. Crystalline lens thi...
