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Topic:Morphology
Morphology in horses refers to the study of the form and structure of the equine body, including the skeletal, muscular, and integumentary systems. This field encompasses the examination of physical characteristics such as body conformation, limb structure, and cranial features, which can influence a horse's performance, health, and suitability for various activities or disciplines. Morphological assessments are often used in breeding programs to select for desirable traits and in veterinary evaluations to identify potential anatomical issues. This page aggregates peer-reviewed research studies and scholarly articles that explore the methodologies, findings, and implications of morphological studies in equine science.
Structural and haemovascular aspects of placental growth throughout gestation in young and aged mares. This investigation was carried out to study the equine placenta from early gestation to near term, with special reference to morphological changes associated with the development of the vasculature of the fetal component of the microcotyledons. Pregnant uteri were removed post mortem from five Thoroughbred mares between 110 and 309 days of gestation, two of which were aged, multiparous animals suffering age-related degenerative changes in their endometrium (endometrosis), while the other three were young, and had primigravid normal healthy uteri. Pieces of endometrium with placenta attached we...
Comparison of proteoglycan and collagen in articular cartilage of horses with naturally developing osteochondrosis and healing osteochondral fragments of experimentally induced fractures. To compare articular cartilage from horses with naturally developing osteochondrosis (OC) with normal articular cartilage and healing cartilage obtained from horses with experimentally induced osteochondral fractures. Methods: 109 specimens of articular cartilage from 78 horses. Methods: Morphologic characteristics, proteoglycan (PG), and type II collagen were analyzed in articular cartilage of OC specimens (group 1), matched healing cartilage obtained 40 days after experimentally induced osteochondral fractures (group 2), and matched normal cartilage from the same sites (group 3). Results: 79...
Scanning electron microscopy of the choroid plexus of the lateral ventricle of the horse. The present study examined the ultrastructure of the choroid plexus of the lateral ventricle of the horse. The material was fixed in 2.5% glutaraldehyde in 0.1 m sodium phosphate buffer, pH 7.3, processed and analysed by scanning electron microscopy. The choroid plexus was characterized by regions with a predominance of villi, which resembled finger-like projections or bunches of grapes, and others where straight and uniform folds predominated. Epithelial cells projected into the ventricle and large amounts of cilia and microvilli were observed on their surface. The choroid glomus corresponded...
Membrane-coating granules and the intercellular cementing substance (membrane-coating material) in the epidermis in different regions of the equine hoof. This study aimed to carry out a comprehensive morphological examination of the structure and ultrastructure of the membrane-coating granules (MCG) and membrane-coating material (MCM) common to all hoof segments as well as segment-specific features in the MCG and MCM regarding their synthesis, structure and biochemical composition. Tissue samples from the hooves of the left front and right hind limb of 20 adult riding horses were used. Samples were preserved and embedded for histological routine methods as well as for histochemical techniques and tracer techniques for light and electron microsc...
Possible negative effects of inbreeding on semen quality in Shetland pony stallions. Inbreeding is widely believed to negatively affect reproductive performance. Indeed, in some species, high levels of inbreeding are thought to be the major cause of poor semen quality. It is, however, not clear whether inbreeding affects fertility in horses. In this study, the relationship between inbreeding and semen quality was examined in 285 immature Shetland pony stallions submitted for breeding soundness examination in March-April of the years 1992-1997. The majority of stallions examined were 3 years old (85%) and their coefficients of inbreeding ranged from 0 to 25% (mean+/-S.D.: 3+/-4...
Comparative morphological study on the tongue and lingual papillae of horses (Perissodactyla) and selected ruminantia (Artiodactyla). A common characteristic of horses, Rocky Mountain goats, and cattle is that they all have a well developed lingual prominence on the dorsal surface of the posterior area of the tongue. Foliate papillae were found in the horse studied but not in the goat or in cattle. The horse filiform papillae had a long and slender external form with a thin and slender CTC, while in the goat and cattle the external form consisted of a large thick main process and the CTC consisted of a bundle of numerous rod-shaped protrusions. The special papilla found on the lingual prominence resembled larger filiform-lik...
Femoral asymmetry in the Thoroughbred racehorse. To investigate the occurrence of geometrical asymmetries in the macro-architecture of left and right femurs from Thoroughbred racehorses previously used in competitive training and racing in New South Wales, Australia. Methods: Detailed postmortem measurements were made of 37 characteristics of left and right femurs from eleven Thoroughbred racehorses euthanased for reasons unrelated to the study. Measurements focused on articulating surfaces and sites of attachment of muscles and ligaments known to be associated with hindlimb locomotion. Results: Five measurements were significantly larger in...
Evolution, systematics, and phylogeography of pleistocene horses in the new world: a molecular perspective. The rich fossil record of horses has made them a classic example of evolutionary processes. However, while the overall picture of equid evolution is well known, the details are surprisingly poorly understood, especially for the later Pliocene and Pleistocene, c. 3 million to 0.01 million years (Ma) ago, and nowhere more so than in the Americas. There is no consensus on the number of equid species or even the number of lineages that existed in these continents. Likewise, the origin of the endemic South American genus Hippidion is unresolved, as is the phylogenetic position of the "stilt-legged"...
Cellular associations and the differential spermiogram: making sense of stallion spermatozoal morphology. Morphologic assessment of spermatozoa is one of the most objective measures in a Breeding Soundness Examination of a stallion. There are different systems for morphologic assessment of spermatozoa. The objectives of this article are to review spermatogenesis, describe clinical sample preparation, discuss previous methods of morphologic classification and explain the use of a differential spermiogram. The advantages of the differential spermiogram method of analysis are discussed, along with its use in delineating intrinsic and extrinsic disturbances in spermatogenesis. Case examples of specifi...
Advanced fertility diagnosis in stallion semen using transmission electron microscopy. Routine semen analysis of stallions is based on light microscopy (LM). However, there are still a number of animals that are subfertile or even infertile not being identified with conventional semen analysis. The objective of this study was to investigate the suitability of transmission electron microscopy (TEM) for advanced fertility diagnosis in stallion. We examined ejaculates of 46 stallions with known fertility. Animals were divided into three different groups: group 1, fertile stallions (pregnant mares> or =70%, n=29); group 2, subfertile stallions (pregnant mares 10-69%, n=14); group 3,...
Left ventricular size and systolic function in Thoroughbred racehorses and their relationships to race performance. Cardiac morphology in human athletes is known to differ, depending on the sports-specific endurance component of their events, whereas anecdotes abound about superlative athletes with large hearts. As the heart determines stroke volume and maximum O(2) uptake in mammals, we undertook a study to test the hypothesis that the morphology of the equine heart would differ between trained horses, depending on race type, and that left ventricular size would be greatest in elite performers. Echocardiography was performed in 482 race-fit Thoroughbreds engaged in either flat (1,000-2,500 m) or jump racin...
Musculoskeletal responses of 2-year-old Thoroughbred horses to early training. 7. Bone and articular cartilage response in the carpus. To describe features of the morphology of the carpus, quantify the thickness of hyaline and calcified cartilage, and to describe the morphology and density of subchondral bone in the third carpal bone (C3) of young Thoroughbred horses in early training. Methods: C3 of seven 2-year-old horses in training and seven untrained horses matched for age, sex and breed were assessed by gross appearance, computed tomography, fine-structure radiography, image analysis of high-resolution photographs, and histology. Results: Macroscopic lesions in cartilage were few and mild, and not significantly differen...
Effects of Carolina rinse solution, dimethyl sulfoxide, and the 21-aminosteroid, U-74389G, on microvascular permeability and morphology of the equine jejunum after low-flow ischemia and reperfusion. To evaluate effects of Carolina rinse solution, dimethyl sulfoxide (DMSO), and 21-aminosteroid, U-74389G, on microvascular permeability and morphology of the equine jejunum after low-flow ischemia and reperfusion. Methods: 20 healthy adult horses. Methods: Under anesthesia, full-thickness biopsy specimens of a distal portion of the jejunum were obtained for baseline measurements. In addition to a control segment, 2 jejunal segments were identified as sham-operated or experimental segments. Experimental segments underwent 60 minutes of low-flow ischemia and 3.5 hours of reperfusion. Treatments ...
Evaluation of architectural changes along the proximal to distal regions of the dorsal laminar interface in the equine hoof. To describe architectural changes along the dorsal laminar interface of the equine foot. Methods: 6 macroscopically normal forefeet obtained from 6 equine cadavers. Methods: Histologic sections of 8 evenly spaced, proximal to distal, samples of the dorsal laminar interface were photographed, digitized, and examined for differences in architecture. Laminar depth; secondary laminar density; number and consistency of bifurcations occurring within the secondary laminae, and areas composed of primary dermal lamina, primary epidermal lamina, and secondary laminar interface were recorded. Data were e...
Mechanical behavior and quantitative morphology of the equine laminar junction. 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...
The presence of myofibroblasts, smooth muscle cells and elastic fibers in the lymphatic collectors of horses. Horses are highly susceptible to lymphedema. Knowledge of the morphological components of lymphatic collectors is therefore essential to understanding the function of the lymphatic system. A better knowledge of the lymphatic system allows the development of more effective treatments against lymphedema. The composition of hypodermal and deep lymphatic collectors was investigated with immunohistochemical staining, using antibodies against proteins of the collector walls from the skin in the hind limbs of 10 healthy horses. Lymphatic collectors can be subdivided into passive (elastic fibers) and ...
Histomorphology of the equine cervix. The cervix provides an effective, morphological barrier between the uterus and the outside world. The aim of this study was to characterize the epithelial morphology and the vascular structures of the equine cervix along the longitudinal and horizontal axis in more detail by light microscopy. For this purpose, cervical tissue specimens that had been removed from five different regions along the caudocranial axis of 10 genitally healthy mares were available. The histological staining was carried out with haematoxylin-eosin, azan according to Heidenhain, periodic acid-Schiff reaction and resorci...
Sarcoplasmic masses in equine skeletal muscle. Sarcoplasmic masses in humans have been associated with various myopathies, although the significance remains elusive. Similar structures have also been observed in equine muscle. The aim of this study was to determine the frequency of such structures in normal and abnormal equine muscle, and to characterize these structures using histological, histochemical, immunohistochemical, ultrastructural, and morphometric analyses. The histological and histochemical appearance was similar to that of human sarcoplasmic masses with a central or subsarcolemmal distribution. Of interest was a predilection ...
Determination of functional and morphologic changes in palmar digital nerves after nonfocused extracorporeal shock wave treatment in horses. To determine functional and morphologic changes in palmar digital nerves after nonfocused extracorporeal shock wave (ESW) treatment in horses. Methods: 6 horses. Methods: The medial and lateral palmar digital nerves of the left forelimb were treated with nonfocused ESWs. The medial palmar digital nerve of the right forelimb served as a nontreated control nerve. At 3, 7, and 35 days after treatment, respectively, 2 horses each were anesthetized and nerves were surgically exposed. Sensory nerve conduction velocities (SNCVs) of treated and control nerves were recorded, after which palmar digital ...
Articular calcified cartilage canals in the third metacarpal bone of 2-year-old thoroughbred racehorses. We describe morphological aspects of the articular calcified cartilage mineralizing front 'tidemark' in the distal joint surface of the third metacarpal bone from 14 horses. Compositional backscattered electron scanning electron microscopy and confocal scanning light microscopy were conducted on polymethylmethacrylate (PMMA)-embedded medio-lateral slices. After maceration, scanning electron microscopy (SEM) was used to study the calcified cartilage surface in the 'wedges' intervening between the slices. An anatomically reproducible clustering of canals in the calcified cartilage was found at o...
Sperm morphology in Estonian and Tori breed stallions. The standard procedure for assessing the breeding potential of a stallion includes the parameter total number of spermatozoa classified as morphologically normal. This study investigated sperm morphology of fresh semen in randomly chosen Estonian (E, n = 8) and Tori (T, n = 7) breed stallions with proven fertility. Two ejaculates were examined from each stallion. An aliquot from each ejaculate was fixed in 1 mL formol-saline immediately after collection and examined with phase-contrast microscope at a magnification 1000x for all types of morphological abnormalities. Furthermore smears were pre...
A redescription of Cylicocyclus adersi Boulenger, 1920 (Nematoda: Strongyloidea: Cyathostominae) parasitic in equids. As part of a revision of the systematics of the Cyathostominea of equids, we determined that the single type-specimen of Cylicocyclus adersi Boulenger, 1920 is missing and a modern description of this rare species parasitic in donkeys Equus asinus L. and zebras E. burchelli (Gray) and E. zebra L. is not available. Systematists at a workshop on the systematics of the Cyathostominea of horses, convened on August 11, 1997 in Sun City, South Africa, listed C. adersi as a species inquirenda . Herein, we provide a redescription of C. adersi and propose a neotype for the species. The distinctive shap...
Retrospective study of the risk factors and prevalence of colic in horses after orthopaedic surgery. The records of 496 orthopaedic operations on 428 horses were reviewed to estimate the prevalence of, and identify the risk factors for, the development of colic in horses after surgery. Colic was defined as any recognised sign of abdominal pain that could not be attributed to a concurrent disease. Fourteen of the horses developed colic; eight of them were undiagnosed, three were classified as impactions, one as tympanic colic of the colon, one as incarceration of the small intestine in the epiploic foramen, and one as left dorsal displacement of the colon in the nephrosplenic space. Morphine w...
Morphological study of the Golgi tendon organ in equine superficial digital flexor tendon. The Golgi tendon organ (GTO) is an encapsulated fusiform mechanoreceptor siding in the musculo-tendinous junction of many animal species. Inhibitory function of afferent nerve fibers distributed from nearby motor units, the organ responds to active tension exerted onto the muscle. The morphological features of the equine GTO have not yet been elucidated. Additionally, there is some controversy regarding to the existence of the GTO in the equine superficial digital flexor tendon (SDFT). Therefore, immunohistochemistry and immunoelectron microscopy using alcian blue (pH 2.5) staining and the sil...
Effect of ovary holding temperature and time on equine granulosa cell apoptosis, oocyte chromatin configuration and cumulus morphology. The effects of ovary holding time and temperature on granulosa cell apoptosis, oocyte chromatin configuration and cumulus morphology were investigated through a series of experiments. Three experiments were performed to determine the effect of ovary holding time and temperature on granulosa cell apoptosis. Ovaries were held (1) at 20, 30 or 35-37 degrees C for up to 2h, (2) at 30 degrees C for 0-1, 1-2, 2-3, 3-4, 4-6 or 6-10h, and (3) granulosa cells were held for 0, 1, 2, 3, 5, 12 or 24h in M199 with Hank's salts at room temperature (suboptimal incubation). Granulosa cell DNA was analysed by ...
Report in Europe of nasal myiasis by Rhinoestrus spp. in horses and donkeys: seasonal patterns and taxonomical considerations. Two species of Rhinoestrus (i.e. Rhinoestrus purpureus (Brauer) and Rhinoestrus usbekistanicus Gan) cause nasal myiasis in horses, donkeys and zebras. In the past 15 years myiasis caused by R. purpureus has been reported in Egypt and by R. usbekistanicus in Senegal and Niger, both in horses and in donkeys. With the aim to investigate the presence of this myiasis in autochthonous horses and donkeys from southern Italy and to study the seasonal trend of larval infection, 212 native horses were necropsied in two slaughterhouses in the Apulia region (site A) from January to November 2003, and 120 ...
Germ cell apoptosis in the testes of normal stallions. Apoptosis in testicular germ cells has been demonstrated in many mammalian species. However, little is known about the stallion (Equus caballus) and rates of apoptosis during spermatogenesis. Morphological and biochemical features of apoptosis reported in other species were used to confirm that the TdT-mediated dUTP Nick end labeling (TUNEL) assay is an acceptable method for identification and quantification of apoptotic germ cells in histological tissue sections from stallion testis. Seminiferous tubules from eight stallions with normal testis size and semen quality were evaluated according t...
The effect of enrofloxacin on cell proliferation and proteoglycans in horse tendon cells. Fluoroquinolone antibiotics have been used widely in humans and domestic animals, including horses, because of their broad-spectrum bactericidal activity, and relative safety. The use of fluoroquinolones, however, is not without risk. Tendonitis and spontaneous tendon rupture have been reported in people during or following therapy with fluoroquinolones. We have studied the effects of enrofloxacin, a fluoroquinolone antibiotic used commonly in domestic animals, on tendon cell cultures established from equine superficial digital flexor tendons. Effects on cell proliferation and morphology were ...
