Topic:Microscopy
Microscopy in equine research involves the use of various microscopic techniques to study the cellular and subcellular structures of horses. This field encompasses the examination of tissues, cells, and microorganisms to gain insights into equine health, disease mechanisms, and physiological processes. Techniques such as light microscopy, electron microscopy, and fluorescence microscopy are employed to observe and analyze samples at high magnification, providing detailed information on morphology and pathology. Microscopy aids in the diagnosis of diseases, identification of pathogens, and evaluation of cellular responses to treatments. This page compiles peer-reviewed research studies and scholarly articles that explore the applications, methodologies, and findings of microscopy in the study of equine biology and medicine.
Coprophilous fungi of the horse. A total of 1267 microfungi, including 35 Myxomycetes, were recorded from the fecal samples of the 60 horses; of these 395 were found on 20 saddle-horse feces, 363 on 20 race-horses and 509 on 20 working horses. Eighty two species representing 53 genera were recorded; of these 7 were Zygomycetes, 18 Ascomycetes, 1 Basidiomycetes and 25 Fungi Imperfecti: 2 Myxomycetes. Common coprophilous fungi are in decreasing order Pilobolus kleinii, Saccobolus depauperatus, Mucor hiemalis, Lasiobolus ciliatus, Podospora curvula, Petriella guttulata, M. circinelloides, Coprinus radiatus, Dictyostelium mucoroi...
Klossiella equi in the kidneys of a horse. The protozoan, Klossiella equi was found in the kidneys of an aged Shetland mare raised in the Fredericton area of New Brunswick. This is the first published report of K. equi in a horse in Canada. The microscopic appearance of the parasite in the kidney is described. A brief discussion of other conditions seen in the horse is also presented.
Equine protozoal myeloencephalitis: a report of two cases from Western Canada. Two cases of nonsuppurative myeloencephalitis are reported which clinically and pathologically resemble equine protozoal myeloencephalitis. Lesions in both horses were associated with Toxoplasma-like organisms visible in microscopic sections. Clinical signs and lesions in one case primarily involved the brain and in the other case principally involved the spinal cord and associated meninges. Positive identification of the organisms was not achieved; however, the etiological agent is unlikely to be a species of Toxoplasma. Recently published studies suggest a species of Sarcocystis is involved....
Isolation of cellulolytic phycomycete fungi from the caecum of the horse. Microscopic examination of horse caecum contents revealed vegetative growth of phycomycete fungi on particles of digesta, and uniflagellated cells similar to fungal zoospores in the liquid phase. Three morphologically distinct isolates of strictly anaerobic phycomycete fungi were obtained from the caecum contents and cultured in vitro. Two of the isolates were able to utilize a wide range of plant carbohydrates for growth, including alpha-cellulose, xylan and particulate starch, and extensively digested water-insoluble plant tissues.
Congealed amniotic fluid in the alveoli of lungs of aborted foals. The alveoli of the lungs of 2 aborted foals contained elongated, dense bodies when examined histologically and by transmission and scanning electron microscopy. By light microscopy, the bodies (10 to 40 micrometers in size) stained intensely with the Gram stain, and up to 10 were present within an alveolus. Electron microscopy determined that such bodies were not cellular in origin but appeared to be a congealed fluid product composed of layers of fibrillar-like material. From the human literature, it was concluded that these intraalveolar bodies were probably congealed amniotic fluid.
GnRH localization in the equine brain and infundibulum: an immunohistochemical study. Immunohistochemical localization of the decapeptide gonadotropin releasing hormone (GnRH) in neural structures in the pony brain and infundibulum (INF) was conducted at the light-microscopic level. This procedure utilized an antiserum generated against GnRH conjugated to bovine serum albumin. In the rostral INF, GnRH was distributed mainly in the external layer, with greatest concentrations adjacent to the long capillary loops of the hypophyseal portal system. The intermediate portion of the INF contained the hormone throughout the external layer, especially in the dorsolateral regions just ve...
Development of the adrenal cortex in the fetal foal: an ultrastructural study. The adrenal cortex from twelve fetal foals (gestational ages from 61 to 300 days) was examined by light and electron microscopy. Adrenal glands from three newborn foals were also examined by light microscopy. Between 61 and 100 days of gestation the adrenal cortex became organised into two distinct regions, the zona glomerulosa and zona fasciculata, which grew steadily in thickness until the 300th day. Between 300 days and birth there was a dramatic increase in the width of the zona fasciculata. From 200 days a narrow band of compact cells marked the cortico-medullary border. Though these cell...
Melioidosis with acute meningoencephalomyelitis in a horse. A case of acute meningoencephalomyelitis caused by infection with Pseudomonas pseudomallei is described. Clinically there was inability to stand, opisthotonus, facial paralysis and nystagmus, rapidly progressing to violent struggling. Gross examination revealed malacia and haemorrhage in the medulla oblongata and adjacent spinal cord. Microscopically there were disseminated focal neutrophilic accumulations in affected areas, perivascular cuffing with mononuclear cells and lymphocytes and marked oedema. Intracellular bacteria were identified in sections stained by the Giemsa method.
[Prevalence and development of two Sarcocystis spp. in the horse (author’s transl)]. The prevalence of Sarcocystis spp. in horses was investigated in a survey at the Munich abattoir during 1978/79. Muscle specimens (oesophagus, diaphragm, sublingual muscle, myocardium) were examined using tryptic digestion. Out of 200 horses 31 (15.5%) were found to be carriers of sarcocysts. No parasites were found in the myocardium. In three animals sarcocysts could be isolated and differentiated in fresh preparations. Cysts with 5 to 11 microns by less than 0.5 microns hairlike, unstable protrusions were classified as Sarcocystis equicanis, whereas those with 2.5 to 4.5 microns by 0.8 to 1....
Propagation of equine infectious anemia virus in horse cell cultures. The Wyoming strain of equine infectious anemia virus was adapted to cell cultures by 7 passages in horse leukocytes and 14 passages in fetal equine dermal and kidney cells. The virus was made evident by electron microscopy and immunodiffusion tests with antigens prepared from culture fluids.
Ischaemic myocardial fibrosis and aortic strongylosis in the horse. The hearts and aortas of 2076 unselected horses of all ages were examined immediately after slaughter. Focal zones of fibrosis, observed in the myocardium of 14.3 per cent of hearts examined, were found in both atria and ventricles and were unrelated to age. Microscopically the majority of lesions involved myocardial fibre lysis and replacement fibrosis, although acute infarction was present in some cases. Intramyocardial arterioles in or adjacent to the lesions exhibited occlusive arteriosclerotic changes whereas those elsewhere remained patent. The evidence strongly suggests that the myocard...
Effect of intraluminal oxygen in intestinal strangulation obstruction in ponies. This study examined the effect of intraluminal oxygen administration on mucosal morphology following intestinal strangulation obstruction (ISO) in anesthetized ponies. The ISO was produced by ligation of the intestinal vasculature in 5 ponies for 50 minutes and 2 ponies for 90 minutes. Two ponies served as controls. Light and scanning electron microscopic examination of intestinal biopsy specimens revealed progressive mucosal degeneration following ISO in nontreated intestines, whereas high magnification scanning electron microscopic examination documented subtle evidence of microvilli disrupt...
Rotavirus infection in foals. Fecal samples from 86 foals with diarrhea were examined by electron microscopy during a 2.5 year period. Of these, 26 (30%) were positive for rotavirus. All of the cases were found in epizootic areas. The disease was produced in an experimental foal by inoculation via stomach tube of a bacteria-free fecal filtrate containing rotavirus. Examination of postmortem tissues from the duodenum and jejunum of 2 naturally infected foals and an experimentally infected foal revealed replicating virus in the intestinal epithelial cells. A limited survey of complement-fixing antibody to rotavirus in horses...
Morphometric estimation of pulmonary diffusion capacity in two horse lungs. The lungs of two half-bred geldings were fixed in situ by instillation of a glutaraldehyde solution into the airways during deep anaesthesia. The body weight of both animals was 510 kg and their average lung volume about 38 l. Stratified random samples from 22 regions were morphometrically analysed from electron microscopic films. Eighty-six per cent of the total lung volume was gas exchange parenchyma. It contained 26.9 l air space and 5.6 l interalveolar septa which were composed of equal parts of capillaries and tissue. The average alveolar and capillary surface areas were 2457 m2 and 1663 ...
Crystalline inclusions in erythrocytes parasitized with Babesia equi following treatment of ponies with imidocarb. Four splenectomized Welsh ponies were infected with Babesia equi. Two ponies were treated with imidocarb dipropionate, and two were not treated. By light microscopic examination, 1% to 2% of the parasitized erythrocytes of treated ponies contained crystalline inclusions. The crystals were rectangular, diamond, or burr shaped. They occupied most of the erythrocytic cytoplasm, and, as a result, the remainder of the pale staining cytoplasm was inconspicuous in Wright-Giemsa-stained blood smears. The size and shape of intraerythrocytic inclusions varied when examined by electron microscopy, but in...
Evidence for Sarcocystis as the etiologic agent of equine protozoal myeloencephalitis. Equine protozoal myeloencephalitis (EPM) was diagnosed in 10 horses. By electron microscopy, schizonts were found in intact host cells of the spinal cords or, more frequently, free in the extracellular spaces. Developmental stages of schizonts differed morphologically, and the late stage of schizogony was characterized by endopolygeny. These findings permitted tentative identification of the protozoon as a Sarcocystis sp. Free merozoites were present in the extracellular spaces or in cells of the spinal cord. Pericytes of capillaries were most frequently parasitized by merozoites were present ...
Maturation of equine epididymal spermatozoa. Spermatozoa from four regions of the epididymis and from ejaculated semen were evaluated for their resistance to cold shock, progressive motility, and structural stability. Spermatozoa were incubated at 38 C and their percentage of eosinophilia was compared with that of spermatozoa cooled to 0 C in 2 minutes, 10 C in 12 minutes, or 4 C in 22 minutes. Spermatozoa motility was estimated visually under phase-contrast microscopy and was recorded by cinematography. Structural stability of spermatozoa incubated in 0.05 M sodium borate buffer, 0.035 M sodium dodecyl sulfate (SDS), 0.002 M dithiothrei...
Incidence and morphology of equine and murine chondrocytic cilia. The incidence and structure of equine and murine chondrocytic cilia were studied using serial sections and transmission electron microscopy. Overall, 96% of all equine chondrocytes and 100% of all murine chondrocytes had one cilium. The structure of these cilia included rootlets, basal feet, alar sheets, and an axoneme of nine peripheral doublets which progressively bent and terminated as they coursed towards the tip of the ciliary shaft. Together with the previous studies on neonatal and adult canine chondrocytic cilia, we conclude that the structure and incidence of chondrocytic cilia does n...
A light and electron microscopic study of sarcocysts in a horse. The structure of sarcocysts in a horse is presented. Light microscopic examination revealed that the maximum cyst dimensions were 136 X 990 micrometers and the cyst walls were striated and 1 to 3 micrometers thick. Electron microscopic examination revealed that the "cyst wall" was formed by villuslike protrusions of the parasitophorous vacuole's primary wall. A unique feature was the presence and arrangement of microtubules within the parasitophorous vacuole. Thirty-four to 55 microtubules extended from the apical tips and sides of each villus and passed through the ground matrix to form junct...
Phycomycosis of the horse caused by Basidiobolus haptosporus. A case of subcutaneous phycomycosis of a horse from which Basidiobolus haptosporu was isolated is described. Although some clinical signs were similar to the disease caused by Hyphomyces destruens, the gross and microscopic pathology were different in several respects. Main characteristics of the histopathology were the narrow eosinophilic sleeve around wide, frequently septate hyphae scattered throughout the affected tissue and found commonly at the advancing border of the lesion. A retrospective study of 63 cases of phycomycosis diagnosed at this laboratory since 1970 indicated a further 11 ...
Negative contrast electron microscopic techniques for diagnosis of viruses of veterinary importance. Negative contrast electron microscopy (NCEM) was utilized as a routine tool in the diagnosis of viral infections of domestic and wild animals. Viruses identified by this technique were observed in infected culture systems or clinical specimens from several species including horses, cattle, sheep, dogs, cats, pigs, deer, Rocky Mountain bighorn sheep, antelope, and several avian species. Viruses were identified by NCEM based on their size, morphology, and symmetry and consisted of adenoviruses, herpesviruses, paramyxoviruses, myxoviruses, picornaviruses, parvoviruses, coronaviruses, reoviruses, ...
Ultrastructure of Babesia equi in ponies treated with imidocarb. Four splenectomized ponies were infected with Babesia equi. Two ponies were not treated, and two were treated with 5 mg of imidocarb/kg of body weight when 20% of their erythrocytes were parasitized. The nucleus of the parasite in erythrocytes from blood smears of nontreated ponies was roundish, deep red-staining, and usually composed two-thirds of the organism. The parasite in erythrocytes from blood smears of treated ponies was swollen and vacuolated except for an area just beneath the plasma membrane where the compressed nucleus was marginated, elongated, and clumpy. Parasites in erythrocyt...
[Rhinosporidiosis in the horse. Histological and electron microscopic study of a case]. No abstract available
[Structure and topography of nucleus dorsalis in the spinal cord of horses]. The material for the study was taken from 2 spinal cords of sexually mature horses. Preparations obtained from this material were stained according to Nissl and with the use of cresyl violet. The nucleus dorsalis of the horse extends from the 8th cervical neuromere to the 3rd lumbar neuromere of the spinal cord. The cells which form this nucleus lie in the grey matter of the spinal cord, dorsolaterally of the central canal. The nucleus dorsalis is made out of large and medium-size round and oval cells. The characteristic feature of the structure and configuration of this nucleus in the horse i...
Ultrastructure of Haemophilus equigenitalis, causative agent of contagious equine metritis. Haemophilus equigenitalis, a proposed new species of Haemophilus and the causative agent of contagious equine metritis, a venereal disease of the horse, had ultrastructural characteristics of gram-negative bacteria. The organism additionally had a small, threadlike capsule that was removed by heating in phosphate-buffered saline solution. Heating also detached the outer membrane from the cytoplasmic membrane. The capsule could only be demonstrated when bacterial were stained with ruthenium red during the preparation of ultrathin sections. The gross morphology of newly isolated organisms (rodli...
The origin of nuclear bodies: a study of the undifferentiated epithelial cells of the equine small intestine. During an electron and light microscopic study of the equine intestinal epithelium, it was observed that some secretory granules of the undifferentiated crypt epithelium were incorporated into the nucleus during mitosis. A study was made of the chemical nature of the granules, using standard histochemical techniques: PAS-Alcian blue, Deamination-PAS, and Ninhydrin-Schiff reactions. The granules contained a neutral protein-polysaccharide complex with many terminal amino groups, possibly an antibody (IgA). The intranuclear granules underwent coalescence and degeneration during differentiation. T...
Evidence of the origin of the gelatinous masses in the oviducts of mares. The gelatinous masses known to occur in the mare oviduct were examined by light and scanning electron microscopy. Many (44%) of the masses which occurred in 16 of the 24 oviducts studied were connected with the mucosa of the ampulla near the ampullary-isthmic junction. The masses consisted of lobules of fine fibres probably derived from the fibrous connective tissue of the lamina propria in the oviductal mucosa.
The location of eggs retained in the oviducts of mares. The oviducts of 24 mares were examined to determine the site of retention of unfertilized eggs. The ampullary-isthmic junction regions of 42 of the 48 oviducts were serially sectioned and examined histologically. The remaining parts of the oviducts were flushed and the flushings searched microscopically. Of 45 eggs located, 40 were in the sectioned segments of 24 oviducts and only 5 were in the flushings. All but one of the sectioned segments contained prominent masses of material obstructing the lumen, but these were apparently not the direct cause of egg retention since eggs were found on bo...