Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
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.
Ultrasonography as a method to determine tendon cross-sectional area. Ultrasonographic cross sectional area (CSA) measurements of equine superficial digital flexor (SDF) tendon were obtained to determine the feasibility of ultrasonography for CSA measurement of tendon in vivo and in vitro. Ultrasonographic measurements were compared with a more traditional CSA measurement method, ink-blot analysis. In addition, values for ultrasonographic SDF tendon mean echogenicity were obtained in vivo and in vitro. The left forelimb SDF tendons of 23 horses were evaluated ultrasonographically. Cross sectional images were acquired at 4-cm intervals distal to the base of the a...
Age-related morphometrical changes of arteries of uterine wall in mares. To investigate the morphological changes of uterine wall arteries associated with the progression of age in Thoroughbred broodmares, uterine wall arteries from 13 mares, aged 2 to 31 years, were studied by routine histomorphometry. The ratio of intimal thickness to external diameter increased due to hyperplasia of elastic fibers and was significantly correlated with age (r = 0.95, P < 0.001). The ratio of medial thickness to external diameter decreased and was also significantly correlated with age (r = -0.84, P < 0.001). Using electron microscopy, it was determined that the cross-sectional ar...
Lymphoid tissues of the ileum in young horses: distribution, structure, and epithelium. Lymphoid tissues in the ileum of young horses form raised plaques that are macroscopically visible from the mucosal surface. These are termed "ileal lymphoid patches". These patches are variable in size, shape and position within the ileal wall, occasionally lying along the site of mesenteric attachment. Within lymphoid patches, follicles exist in three different morphological forms: follicle/dome structures, proprial follicles, and lymphoglandular complexes (LGCs). In follicle/dome structures, the majority of the follicle lies in the submucosa and merges with a dome in the lamina propria thro...
An evaluation of the accuracy of ageing horses by their dentition: changes of dental morphology with age. 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...
Microvascular permeability and endothelial cell morphology associated with low-flow ischemia/reperfusion injury in the equine jejunum. Microvascular permeability of the jejunum of clinically normal equids and microvascular permeability associated with 60 minutes of ischemia (25% baseline blood flow) and subsequent reperfusion were investigated. Eight adult horses were randomly allotted to 2 equal groups: normal and ischemic/reperfusion injury. Lymphatic flow rates, mesenteric blood flow, and lymph and plasma protein concentrations were determined at 15-minute intervals throughout the study. Microvascular permeability was determined by estimates of the osmotic reflection coefficient, which was determined when the ratio of lymp...
Morphologic changes of the ascending colon during experimental ischemia and reperfusion in ponies. The morphologic changes following ascending colon volvulus result from the interaction of inflammatory and coagulation mediators. The objective of this study was to establish a quantifiable histopathologic scoring system to evaluate the serial pathomorphologic changes during ischemia and reperfusion. Such a scoring system could then be applied to subsequent studies designed to attenuate bowel lesions by regulating activity of individual mediators. Ten normal, healthy adult ponies were randomly divided into two equal groups. Following anesthesia and a 30-minute stabilization period, the colon o...
Relationship among seminal characteristics, fertility and suitability for semen preservation in draft stallions. Seminal characteristics, fertility and the response to semen preservation (liquid storage and cryopreservation) were evaluated in 4 Draft stallions (Percheron 2, Breton 2). Seminal characteristics (gel-free volume, sperm concentration, sperm morphology, percentage of motile spermatozoa) were assessed in 5 ejaculates from each of the 4 stallions. The fertility of the stallions was calculated retrospectively as the accumulated pregnancy rate over 3 breeding seasons. Five ejaculates from each of the stallions were subjected to liquid storage at 5 degrees C. The percentage of motile spermatozoa (P...
Spontaneous equine pulmonary granular cell tumors: morphologic, histochemical, and immunohistochemical characterization. Spontaneous equine pulmonary granular cell tumors were diagnosed in six mature horses at slaughter. These tumors were grossly recognized as multiple (5/6) or single (1/6) creamy white, firm nodules. The tumors, located adjacent to bronchi and bronchioles, often invaded airways, resulting in partial to complete occlusion of the lumina. Neoplastic cells were rounded to polyhedral with numerous eosinophilic cytoplasmic granules that reacted uniformly positive with S-100 and neuron-specific enolase antibodies and multifocally with glial fibrillary acidic protein antibodies. These cells were negati...
Influence of stochastic events on the phenotypic variation of common white leg markings in the Arabian horse: implications for various genetic disorders in humans. One method of assessing the influence of stochastic events on phenotypic variation is to study morphological differences in paired limbs of the same individual. These limbs have identical genotypes and similar intra-uterine environments and are analogous to monozygotic twins. Common white leg markings have a multifactorial mode of inheritance in the Arabian horse. Asymmetry occurs frequently for these markings. Using computerized registration records obtained from the Arabian Horse Registry of America, Inc., the types of markings were quantified in the left foreleg and left hind leg of bay and...
Morphology and location of attached follicular cumulus-oocyte complexes in horses, cattle and llamas. Morphology and location of the attached cumulus-oocyte complex (COC) were studied in slaughter-house ovaries in horses (49 follicles, 9 to 44 mm), cattle (68 follicles, 6 to 18 mm), and llamas (38 follicles, 3 to 14 mm). The expected point of ovulation was marked, using the ovulation fossa in mares and the center of the projecting follicular surface in cattle and llamas. A follicle was dissected from an ovary, and tissue was removed from the follicle until the COC became visible by transillumination. However, most llama follicles protruded prominently from the ovarian surface so that dissectio...
Fibrosing granulomas in the equine liver and peritoneum: a retrospective morphologic study. Fibrosing granulomas were found in the liver and occasionally on the intestinal and diaphragmatic serosae and in the lung of 11 horses submitted for necropsy. Although these granulomas were considered incidental findings in most of the horses, they had caused liver failure in 1 horse. The granulomas typically were characterized by a dense collagenous core that frequently was mineralized. The periphery contained a rim of inflammatory cells. Only in 1 of the 11 horses was there evidence of an egg shell suggestive of schistosomes. Schistosomal eggs were not detected in the feces of the horses. Th...
A scanning electron-microscopic analysis of the morphology of equine lower lip sinus hair. Sinus hairs, which are tactile organs of most mammals, are differentiated into cavernous and sinus types. The horse has the cavernous type. Horse lower lips were perfused in diluted Karnovsky's fixative and sinus hair processed for scanning electron microscopy. Anastomosing trabeculae of different thickness and shape originate from the internal connective tissue layer and extend to the external layer, thus forming a dense meshwork suspending the hair root like a net. However, many of the distal trabeculae do not reach the external wall of the blood sinus but end in a finger-like knob within th...
Spermatophagy in the stallion epididymis: a scanning and transmission electron microscopy study. The occurrence of phagocytosis of spermatozoa in the epididymis is a controversial issue in male reproductive biology. In this paper we documented, by scanning and electron microscopy, the presence of spermatophages in the lumen of the proximal region of stallion epididymis. Sperm phagocytosis involving the principal cells that line the cauda epididymidis region was also observed. The possible meaning of this process in the removal of damaged, aged or surplus spermatozoa is discussed. These observations were made in samples obtained from random cases, during the course of research work carried...
The equine enteric nervous system–neuron characterization and distribution in adults and juveniles. A study of myenteric and submucosal plexuses was undertaken in the jejunum and ileum of horses and ponies in which no clinical or pathological evidence of intestinal abnormality was apparent. Complete transverse sections of the intestine, stained by a modified haematoxylin and eosin method, were examined using up to 20 sequential sections per animal. Information was gathered from adult, juvenile and fetal equidae. In adults, the longitudinal muscle layers were thinner than the circular muscle layers and the ileum had thicker layers compared to the jejunum. In adults, the submucosal plexus had ...
Morphologic and morphometric characterization of lung collagen content in clinically normal adult thoroughbreds in race training. Interstitial and bronchointerstitial pulmonary patterns are commonly observed in thoracic radiographs of Thoroughbreds. Prominent interstitial and bronchointerstitial pulmonary patterns are observed in clinically normal horses, and in horses with respiratory tract disease. Until recently, the relevance of these pulmonary patterns was not known. Previous studies indicated that bronchiolitis, bronchiolar epithelial hyperplasia, epithelial metaplasia, and bronchial arteriolar recruitment correlated strongly with the prominence of the interstitial and bronchointerstitial pulmonary patterns observe...
Ultrasonographic morphology of the bicipital tendon and bursa in clinically normal quarter horses. The bicipital tendons and bursae of 25 healthy adult Quarter Horses were ultrasonographically examined. Cross-sectional images of the right and left bicipital tendons were obtained from each horse, using a 7.5-MHz transducer held in the frontal plane at the point of the shoulder. The bicipital tendon at the point of the shoulder appeared as a bilobate structure overlying the echogenic surface of the humerus. Median distance from the skin surface to the cranial surface of the tendon on the medial sagittal plane of the tendon was 23 mm (range, 16.5 to 30 mm); median distance on the lateral sagit...
Prolonged gestation, decreased triiodothyronine concentration, and thyroid gland histomorphologic features in newborn foals of mares grazing Acremonion coenophialum-infected fescue. Newborn foals of mares grazing on Acremonium coenophialum-infected fescue pasture throughout gestation or from gestation day 300 to parturition had increased gestation duration and decreased serum triiodothyronine concentration. Pregnant mares were allotted to 4 treatments: grazing continuously on endophyte-free (E-) fescue, grazing continuously on endophyte-infected (E+) fescue, grazing on E+ fescue from gestation day 300 to parturition, and grazing on E+ fescue from conception to gestation day 300. Morphometric studies indicated that foals born to mares exposed to endophyte late in gestation...
Crystalline composition of equine urinary sabulous deposits. The composition and crystal morphology of 141 equine sabulous deposits were determined by infrared spectroscopy (IR), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The IR analysis revealed that all investigated deposits contained calcium carbonates (calcite, CaCO3, and/or vaterite, CaCO3) as major constituents; 42 samples were composed of calcite and vaterite, 33 of calcite, 18 of calcite/vaterite and calcium oxalate, and 17 of vaterite. The remaining specimens contained calcite/vaterite and other compounds (calcium phosphates, sulphate and/or oxalates and/or s...
Different fibrillar architectures coexisting in Haversian bone. Samples of compact bone were deproteinated by heat treatment and analysed by SEM. This technique removes very effectively cells and vascular structures and brings into full view the mineralization front along the wall of the Havers canal. The present study was confined to samples of equine bone that are known to be subjected to different functional requirements. Bone subjected to high tensile stress exhibited collagen fibrils substantially aligned with the stress direction, and the vast majority of its osteons appeared made of almost parallel fibrils crossing at very narrow angles. On the cont...
Antigenic, morphologic, and molecular characterization of new Ehrlichia risticii isolates. Ehrlichia risticii causes an acute infectious disease in horses called Potomac horse fever. To investigate the biological diversity of E. risticii organisms, nine E. risticii isolates derived from the peripheral blood monocytes of clinically sick horses in Ohio and Kentucky during the summers of 1991 and 1993 were compared with Illinois and Virginia isolates originally obtained from horses in Maryland in 1984. Seven of the nine isolates (081, 606, 380, 679, As, Co, and Ov) formed large morulae (tightly packed inclusions of ehrlichial organisms). The remaining isolates, including 1984 isolates,...
Morphological analysis of cervical vertebrae in ataxic foals. Morphological differences between cervical vertebrae were statistically analyzed in ataxic foals to clarify abnormal structural factors in the pathogenesis of this problem. At first, multiple regression analysis and cluster analysis were performed with 28 variables in C3-C7 of 39 control foals without lameness. As a result, there were no sex differences in the growth of all cervical vertebral sites, and the most suitable categorization of the age of the foals was 3 clusters of 8 months old or younger, 9-12 months old and 13 months old or older in any sites in the cervical vertebrae. Twenty-eig...
Induction of superovulation in DD mice at different stages of the oestrous cycle. This study examined the developmental capacity of oocytes in DD mice after they had been injected with pregnant mares' serum gonadotrophin at different stages of the oestrous cycle. The superovulation of mature DD mice at pro-oestrus, oestrus and metoestrus resulted in a large yield of viable embryos. The proportion of abnormal embryos was highest after injection of pregnant mares' serum gonadotrophin at dioestrus. The pool of viable oocytes was most synchronized with normal development after the hormone was injected at oestrus. The results demonstrate that oocytes of different morphology coul...
Neutrophil accumulation in the large colon of horses during low-flow ischemia and reperfusion. Histomorphologic/morphometric evaluation, leukocyte scintigraphy, and myeloperoxidase activity were used to determine whether neutrophils accumulate in the large colon of horses during low-flow ischemia and reperfusion. Twenty-four adult horses were assigned to 1 of 3 groups: group 1, sham-operated (n = 6); group 2, 6 hours of ischemia (n = 9); and group 3, 3 hours of ischemia and 3 hours of reperfusion (n = 9). Low-flow ischemia of the large colon was induced in horses of groups 2 and 3 by reducing colonic arterial blood flow to 20% of baseline. Radiolabeled (99mTc) autogenous neutrophils wer...
In vitro viability of cryopreserved equine embryos following different freezing protocols. The main objective of this study was to evaluate two freezing protocols and the effect of agar embedding on survival of day 6.5 equine embryos. A total of 133 embryos were used, in one group (n = 51), embryos were first embedded in agar before the freezing protocol was started. A freezing protocol to -30 degrees C or -33 degrees C was used before plunging embryos into liquid nitrogen (LN2). The embryos were thawed in water at 37 degrees C, evaluated and placed in culture. After 24 h culture, the embryos were evaluated for their morphology and development. No differences were observed between e...
Isolation of cell populations from the mare corpus luteum: comparison of mechanical and collagenase dissociation. Corpora lutea were obtained from mares at days 3, 10 and 14 after ovulation, and examined histologically. The morphology of isolated luteal cells obtained by either mechanical or collagenase dissociation of the tissue was examined and the cells stained to detect the steroidogenic enzyme delta 5, beta-hydroxysteroid dehydrogenase. The ratio of large:small cells was significantly higher for cells obtained from mechanically dissociated luteal tissue than for cells obtained by collagenase dissociation (P < 0.01). Cells obtained by both mechanical and collagenase dissociation secreted progestero...
The pathobiology and repair of tendon and ligament injury. Injury of the collagenous structures comprising tendons and ligaments, either from acute trauma or from repetitive strain lesions, results in protracted periods of disability. The resolution of such injuries often fails to restore the normal morphologic and functional characteristics of the structure and, therefore, either compromises the future performance of the individual or predisposes to an increased risk of recurrent injury.
Morphologic characteristics of equine endometrium classified as Kenney categories I, II, and III, using light and scanning electron microscopy. Pathologic changes in the endometrium of mares may be rated according to Kenney's method of classification. Category I endometrium contains healthy tissue with no or few widely scattered pathologic changes. At the opposite end, severe widespread pathologic changes are associated with category III. Uterine biopsy specimens were collected aseptically from 16 mares during the estrous and diestrous stages of the cycle. Pathologic changes were evaluated, using light microscopy, and endometrium was classified as Kenney's category I, II, or III. Endometrial tissue of category I (n = 5 mares in estrus...
[Morphologic and molecular biologic studies of the etiology of equine sarcoid]. From 932 equine skin lesions 421 were diagnosed as sarcoids (about 45%). The most common locations were the ventral body regions, head, neck and sites of thin skin. Most often the fibroblastic type, less frequently the mixed type and most infrequent the verrucous type of sarcoid were diagnosed. Detection of BPV-DNA was performed by polymerase chain reaction (PCR) using an oligonucleotide primer pair located in the E5-open reading frame. DNA of BPV 1 and BPV 2 could be differentiated by digestion with restriction endonucleases. In 97 out of 108 sarcoids BPV-DNA was detected by PCR. Most samples...
A subpopulation of morphologically normal, motile spermatozoa attach to equine oviductal epithelial cell monolayers. Attachment of spermatozoa to oviductal epithelial cells (OEC) may be a prefertilization event in some species. We tested the hypothesis that spermatozoa that attach to equine OEC monolayers are a selected subpopulation of the initial inseminate, containing a higher proportion of morphologically normal, motile cells than the inseminate. Washed stallion spermatozoa were cocultured with monolayers of OEC or monolayers of Vero cells, and controls were incubated in wells coated with basement membrane extract (Matrigel [Mgel]) or in plastic (uncoated) wells. Unattached spermatozoa were removed by ri...
