Histology in horses involves the microscopic examination of tissues to understand their structure and function. This field of study provides insights into the cellular composition and architecture of equine tissues, aiding in the diagnosis of diseases and the assessment of tissue health. Histological analysis is used to identify pathological changes, such as inflammation, neoplasia, or degenerative conditions, by examining tissue samples obtained through biopsies or necropsies. Common tissues studied in equine histology include skin, muscle, bone, and internal organs. This page compiles peer-reviewed research studies and scholarly articles that explore histological techniques, findings, and their applications in equine veterinary medicine.
Ludewig T.Corpora amylacea are present in all the mammary glands of the investigated animals (ewe, goat, and mares). Generally, they are comparable to the cow regarding to its distribution, frequency, size, morphological structure, and staining properties. Corpora amylacea occur most frequently in the ewe, and in non-lactating mammary glands. In lactating mammary glands they are mostly situated in the alveoles. During gestation they are located outside of the alveoles and in the interalveolar connective tissue. Only in very few cases corpora amylacea are found inside and outside of the alveoles in the s...
Becker CK, Savelberg HH, Buchner HH, Barneveld A.To evaluate posttrauma biomechanical behavior of the scar attributable to desmotomy of the accessory ligament of the deep digital flexor tendon (AL-DDFT), compared with the histomorphologic and ultrasonographic appearance. Methods: 5 Standardbred trotters. Methods: Gross appearance, length, cross-sectional area (CSA), in vitro material properties, and ultrasonographic and histomorphologic features were studied 6 months after desmotomy. Tensile tests were conducted, with forces and elongation simultaneously recorded. Surgically treated limbs were compared with nontreated contralateral limbs. Re...
Norrdin RW, Kawcak CE, Capwell BA, McIlwraith CW.Gross examination of metacarpo-/metatarsophalangeal (fetlock) joints from racehorses revealed defects on the condylar surface that ranged from cartilage fibrillation and erosion to focal cartilage indentations and cavitation in subchondral bone characteristic of traumatic osteochondrosis. Because these lesions represented a spectrum of mechanically induced arthrosis in which microdamage is thought to play a role, a histologic study of sagittal sections was made to study the morphogenesis. Subchondral bone failure developed beneath a flattened section of the condyle where the margin of the sesa...
Wille KH, Zahner M.The vascular system of the large intestine of 12 horses was examined by means of vascular corrosion casts, histology and transmission electron microscopy providing the following results. The Aa. et Vv. breves et longae leave the mesenteric vessels, respectively the subserously on the teniae lying cecal vessels to reach the tela subserosa at the mesenteric margin. The short vessels enter the deeper layers of the wall instantly, whereas the Aa. et Vv. longae move towards the submucosa by penetrating the muscular layers after a variable subserous course. The tela submucosa contains an arterial an...
Trostle SS, White NA, Donaldson L, Freeman LJ, Hendrickson DA.To describe a technique for laparoscopic colopexy in horses. Methods: Description of a technique to perform laparoscopic colopexy in horses. Methods: Six healthy adult horses between 3 and 23 years of age and weighing between 440 and 636 kg. Methods: Horses were positioned in dorsal recumbency, and the abdomen was insufflated to an intraabdominal pressure of 15 mm Hg. A laparoscope portal was placed at the umbilicus, and instrument portals were placed cranial to the laparoscope and lateral to midline. The lateral taenia of the left ventral colon was laparoscopically identified and retracted wi...
Latimer FG, Blackford JT, Valk N, Wan P, Patton S.To use gastrointestinal linear stapling instrumentation to perform a closed one-stage functional end-to-end jejunojejunostomy in adult horses as an alternative to a stapled side-to-side jejunojejunostomy. Methods: Clinical outcome, anatomic and histological architecture, and anastomotic dimensions were determined at 2, 4, 8, 16, and 24 weeks postoperatively. Methods: 18 adult horses. Methods: The anastomosis and peritoneal cavity were inspected for adhesions. The diameter and circumference of the anastomosis and jejunum oral and aboral to the anastomosis were determined from digitized contrast...
Ludewig T.The purpose of the study was to give a histological picture of the different skin regions of the mammary gland in mares. Special emphasis on the dark coating in the sulcus intermammarius was given. As a result, the dark pigmented udder skin can be subdivided into the skin of the Corpus mammae, the sulcus intermammarius and the teat skin. In the sulcus intermammarius the whole epidermis was considerably thicker than usual, especially the stratum corneum (up to 70 layers of cornified layers) and the stratum spinosum. In general, the squamous keratinocytes were unusually large. The histological p...
Frank N, Hawkins JF, Couëtil LL, Raymond JT.A 17-year-old pony mare was admitted for evaluation of progressive enlargement of the facial bones during the preceding 9 months. Laboratory testing revealed that the pony had hypercalcemia, hypophosphatemia, high urinary fractional excretion of phosphorus, and high serum concentration of intact parathyroid hormone (185.1 pmol/L; reference range, 0.25 to 2.0 pmol/L). On the basis of these findings, a diagnosis of primary hyperparathyroidism was made by ruling out nutritional secondary hyperparathyroidism, chronic renal disease, and pseudohyperparathyroidism resulting from neoplasia. Although p...
Kawcak CE, Frisbie DD, Trotter GW, McIlwraith CW, Gillette SM, Powers BE, Walton RM.To evaluate the effects of arthroscopic surgery, osteochondral fragmentation, and treatment with IV administered hyaluronate on histologic, histochemical, and biochemical measurements within the carpal joints of horses. Methods: 12 clinically normal horses, 2 to 7 years of age. Methods: Horses had an osteochondral fragment created at the distal aspect of the radiocarpal bone of 1 randomly chosen middle carpal joint to simulate osteochondral fragmentation. Horses were treated with 40 mg of hyaluronate or saline solution (placebo) intravenously once a week for 3 consecutive weeks (days 13, 20, a...
Heilkenbrinker T, Kossin C, Scherbarth R, Frerking H.In this paper, fertility relevant parameters which are routinely examined in practice were evaluated on the basis of their correlation to one another and their influence on the foaling rates and incidence of early embryonic death in 175 brood mares of the Hanover breeding stock. The aim was to evaluate the suitability of these parameters for inclusion in a scheme for increasing the precision of predicting the subsequent course of pregnancy, as compared to such prognoses based exclusively on the histological evaluation of the endometrium. After establishing the breeding history and completing a...
Hooper PT, Ketterer PJ, Hyatt AD, Russell GM.Laboratory examinations of equine morbillivirus included experimental reproductions of the disease caused by the virus by transmission of mixed lung and spleen taken from two field equine cases into two horses and by inoculating tissue culture virus into a further two horses. The most distinctive gross lesions of the diseases that developed in three of the horses was that of pulmonary edema characterized by gelatinous distension of subpleural lymphatics. Histologically, the lesions in the lungs were those of serofibrinous alveolar edema, alveolar macrophages, hemorrhage, thrombosis of capillar...
Henson FM, Davies ME, Jeffcott LB.This study describes (1) the histological appearance of dyschondroplasia, the primary lesion of osteochondrosis, in articular cartilage of the horse and (2) the localization of type VI collagen which is an important constituent of the extracellular matrix (ECM). Dyschondroplastic cartilage was identified on the basis of the presence of cartilage cores (i.e., cartilage extending into the subchondral bone) and confirmed with subsequent histological examination. Full-thickness cartilage samples from 57 horses were collected and paraffin embedded. Histological examination was used to examine the n...
Hagiwara K, Momiyama N, Taniyama H, Nakaya T, Tsunoda N, Ishihara C, Ikuta K.Sero- and molecular-epidemiological studies on Borna disease virus (BDV) infection show that BDV RNA is not always detected in the peripheral blood mononuclear cells (PBMCs) from serum anti-BDV antibody-positive individuals such as horses, sheep, cattle, cats, and humans. In this study we demonstrated BDV RNA signals by polymerase chain reaction only in restricted regions of the brain from horses with locomotor disease. Four of six horses examined showed apparently positive reactions for anti-BDV antibodies. Specific regions of the brain of these four horses were positive for BDV RNA but the i...
Kato M, Higuchi T, Orita Y, Ishikawa Y, Kadota K.A hepatic malignant tumour composed of both hepatocellular and cholangiocellular elements was studied histologically, immunohistochemically and electron microscopically in an 18-year-old Thoroughbred mare. Bile canaliculi and alpha-fetoprotein were useful in identifying the hepatocellular element, and mucin and keratin were good markers of biliary differentiation. The simultaneous presence of bile canaliculi and mucin-producing cells in most of the neoplastic lesions suggested that this tumour arose from a stem cell with capacity to differentiate into hepatocytes and biliary epithelium.
Kilic S, Dixon PM, Kempson SA.Gross and microscopic examinations were undertaken on 46 cheek (molar and premolar) and 4 incisor equine teeth that were fractured, or sectioned either with a lathe or diamond saw. Specimens were examined without treatment, after decalcification or acid etching, utilising light, and scanning and transmission electron microscopy. In some horses, the occlusal surface of the teeth were covered with an organic pellicle. The occlusal surface of the underlying equine enamel contained different wear patterns, including polished areas, local fractures, wedge-shaped pits, striations and depressions. Oc...
Landolt G, Feige K, Grest P.A 13-year-old warmblood mare was presented because of progressive weight loss, general weakness and trembling. On examination the horse stood with its head lowered and the limbs placed under the body. On lifting its head spasms of the neck muscles could be observed. At the same time the horse developed trembling over the lower neck and muscle fasciculations continued over the whole body. Additional signs included frequent recumbency, polyphagia and facial hyperaesthesia. The horse showed no signs of ataxia. Haematology was normal. Blood biochemistry revealed slight increased aspartate aminotra...
Kilic S, Dixon PM, Kempson SA.Ultrastructural examinations of defined 3 equine enamel types termed equine (Eq.) Types 1, 2 and 3 enamel, according to the transverse appearance of their enamel prisms and the amount and appearance of their interprismatic enamel. Eq. Type 1 enamel contained alternating rows of oval shaped prisms and thick interprismatic enamel plates, and was found adjacent to the amelodentinal junction. Eq. Type 2 enamel consisted of circular, 'keyhole' to 'horseshoe' shaped prisms with little or no interprismatic enamel and was located adjacent to the amelocemental junction. Eq. Type 3 enamel was composed o...
Kilic S, Dixon PM, Kempson SA.Ultrastructural examinations of equine dentine found that dentinal tubules extended from the amelodentinal junction towards the pulp forming primary curvatures. The number of dentinal tubules/unit area and their diameters increased significantly from the amelodentinal junction towards the pulp cavities, particularly in regular secondary dentine, but irregular secondary (tertiary) dentine contained no dentinal tubules. Dentinal tubules contained odontoblast processes that appeared to extend as far as the amelodentinal junction, but due to iatrogenic loss during specimen preparation, odontoblast...
Crevier-Denoix N, Collobert C, Pourcelot P, Denoix JM, Sanaa M, Geiger D, Bernard N, Ribot X, Bortolussi C, Bousseau B.The objective of this study was to mechanically characterise superficial digital flexor tendon (SDFT) lesions. Eight pathological SDFTs, isolated from 6 adult horses, were tested in traction until rupture (at 1 mm/s). The stresses and strains simultaneously undergone by each of the 7 segments of a tendon were determined throughout the test, and the modulus of elasticity of each segment was evaluated from the segmental stress-strain curve thus obtained. These mechanical data were compared to those obtained on 10 normal SDFTs. After the test, the tendinous segments were submitted to a histologic...
Gillis C, Pool RR, Meagher DM, Stover SM, Reiser K, Willits N.To assess tendon morphology and non-reducible crosslink concentration, and associations of these findings with horse age and previously reported mechanical and ultrasonographic findings. Methods: Superficial digital flexor tendon samples were obtained from 23 horses aged 2 to 23 years. The tendons had undergone ultrasonography and were submitted to biomechanical testing in the physiologic range prior to sample acquisition. Methods: Samples were sectioned in a transverse plane; then dorsal, palmar, central, lateral, and medial regions were evaluated for fascicle cross-sectional area (CSA), sept...
Murphy DJ, Nixon AJ.To examine the site-specific and dose-dependent effects of insulin-like growth factor I (IGF-I) on normal equine tendon in vitro. Methods: Superficial digital flexor tendon explants derived from a euthanatized 3-year-old horse. Methods: Explants in culture were treated with 0, 100, 250, or 500 ng of IGF-I/ml for 14 days with an end-stage radiolabel of 20 microCi of [3H]proline/ml or 5 microCi of [3H]thymidine/ml. The tendon tissues were then analyzed biochemically for hydroxyproline content by reverse-phase high-performance liquid chromatography, DNA content by fluorometry, and glycosaminoglyc...
Welle MM, Audigé L, Belz JP.Endometrial biopsies of 44 broodmares were histologically examined on days 3, 6, and 9 postpartum. The mares were subdivided into three groups according to the course of the puerperal period. In 29 mares, parturition and expulsion of the placenta was normal, six mares showed dystocia, and in nine mares, the placenta was retained for > 2 hours. Tissue samples were evaluated histologically, and the average numbers of granulocytes, lymphocytes, macrophages, siderophages, and mast cells was determined. Protease content of mast cells was examined with a double-enzyme immunohistochemical staining te...
Lillich JD, Bertone AL, Malemud CJ, Weisbrode SE, Ruggles AJ, Stevenson S.To compare the biochemical, histochemical, and immunohistochemical profiles of articular cartilage from horses with naturally acquired distal tibial osteochondrosis (OC) with cartilage from a similar location in clinically normal horses. Methods: 9 affected horses (group 1, 16 OC lesions) and 4 control horses (group 2, 8 normal osteochondral specimens). Methods: OC specimens were collected during arthroscopic removal of the fragment, and control specimens were collected by aseptic osteotomy. Uronic acid, total protein, total glycosaminoglycan (GAG), chondroitin sulfate (CS), and keratan sulfat...
Izumisawa Y, Yamaguchi M, Bertone AL, Tangkawattana P, Masty J, Yamashita K, Kotani T.The structural arrangement and cellular distribution of endothelial and lining cells of the synovial villi were studied in the equine palmar/plantar recess of the metacarpo- and metatarsophalangeal joints by light microscopy and electron microscopy. The extent and distribution of blood vessels varied with villous shape and length. The majority of vessels formed concentric circles in cross and longitudinal sections and probably are arranged in a convoluted, spiral or helical pattern. The villi do not contain smooth muscle cells or typical capillaries as observed in other organs. Under the elect...
Martin RB, Lau ST, Mathews PV, Gibson VA, Stover SM.We studied birefringence as an indicator of collagen fiber orientation in the diaphysis of the equine third metacarpal bone. We had previously shown that tissue from the lateral cortex of this bone is stronger monotonically, but less fatigue resistant, than tissue from the medial and dorsal regions. To learn whether collagen fiber orientation might play a role in this regional specialization, we tested three hypotheses using the same specimens: (1) collagen fiber orientation is regionally dependent; (2) remodeling changes collagen fiber orientation; (3) longitudinal collagen fibers correlate p...
Vickers KL, Ross MW.A 4-year-old sexually intact male Standardbred trotter was evaluated for left forelimb lameness. A presumptive diagnosis of severe cartilage damage was made because the horse had a history of infectious arthritis involving the left metacarpophalangeal joint. Arthroscopic evaluation revealed what was presumed to be a large villonodular lesion. The mass was surgically removed, and the horse was treated with procaine penicillin G, trimethoprim-sulfamethoxazole, phenylbutazone, and polysulfated glycosaminoglycans and eventually returned to racing. Histologic examination of the mass revealed a bed ...
Marshall DE, Dumasia MC, Wooding P, Gower DB, Houghton E.Maternal endometrial and fetal allantochorionic tissues were separated manually from the placentae of seven healthy thoroughbred and three pony mares, ranging in gestational age from 100 to 318 days. The homogeneity of subcellular fractions prepared from these tissues was assessed initially using the marker enzymes, succinate dehydrogenase, NADPH cytochrome C reductase and lactate dehydrogenase for the mitochondrial, microsomal and cytosolic fractions, respectively. Light microscopy and histochemical analysis demonstrated that the separated fetal allantochorionic membrane, which is made up of ...
Martinelli MJ, Baker GJ, Clarkson RB, Eurell JC, Pijanowski GJ, Kuriashkin IV, Carragher BO.To expand our current knowledge and to establish limits of correlation between signal intensities of the magnetic resonance (MR) image and actual macroscopic and microscopic anatomic features of the imaged structures of the equine metacarpophalangeal joint (MCPJ). Methods: The right MCPJ was obtained from 4 adult horses that were euthanatized for reasons unrelated to the musculoskeletal system. Methods: The distal portion of the right forelimbs was collected from 4 equine cadavers. The bones were drilled to provide fixed reference points and examined by MR imaging. After imaging, the joints we...
Martin RB, Stover SM, Gibson VA, Gibeling JC, Griffin LV.We studied remodeling and microcrack damage in specimens of Thoroughbred racehorse third metacarpal bone that had been subjected to monotonic or fatigue failure. We asked three questions. What effects does mechanical loading have on histologically observable microcrack damage? Are there regional variations in remodeling of the equine cannon bone, and do these variations correlate with mechanical properties? To what extent are remodeling and microcrack damage age-dependent? Machined beams from the medial, lateral, and dorsal cortices were loaded to fracture in four-point bending monotonically, ...
Ludewig T.Corpora amylacea are present in all the mammary glands of the investigated animals (ewe, goat, and mares). Generally, they are comparable to the cow regarding to its distribution, frequency, size, morphological structure, and staining properties. Corpora amylacea occur most frequently in the ewe, and in non-lactating mammary glands. In lactating mammary glands they are mostly situated in the alveoles. During gestation they are located outside of the alveoles and in the interalveolar connective tissue. Only in very few cases corpora amylacea are found inside and outside of the alveoles in the s...
Madison JB, Hamir AN, Ehrlich HP, Haberman J, Topkis V, Villasin JV.Full-thickness skin wounds were created on the dorsum of both metacarpi in 8 horses. Three topical treatment regimens were studied. All wounds were bandaged with a nonadherent dressing, which was held in place with a snug elastic wrap. Group-A wounds were treated with a proprietary topical wound medication that consisted of a spray and an ointment. Group-B wounds were treated with the same regimen, except the putative active ingredients in the ointment were omitted. Group-C wounds were treated with a dry nonadherent bandage only. Wound dressings were changed every day and the limbs were photog...
Genton M, Robert C, Jerbi H, Huet H, Cordonnier N, Vitte-Rossignol A, Perkins JD, Rossignol F.To describe the innervation of the thyrohyoideus (TH) muscle and to confirm our findings with stimulation of first cervical (C1) nerve branches. Methods: Ex vivo phase 1 and clinical phase 2. Methods: Fourteen head and neck specimens and 17 client-owned horses. Methods: In phase 1, the cranial nerve (CN) XII and the C1 nerve were dissected with their branches in 20 dissections were performed on 14 specimens (6 left and right side and 8 only left or right) Anatomy was noted. Samples of nerve bifurcations were collected for histological confirmation of anatomical findings. First cervical nerve b...
Jeffcott LB, Kold SE, Melsen F.The gross and histological appearance of subchondral bone cysts in six Thoroughbred or partbred horses is described. The lesions were all situated in the centre of the medial femoral condyle and were not associated with any other damage to the articular surface of the femorotibial or femoropatellar joints. In three cases the cysts were unilateral but had an early non-cystic lesion present in the opposite stifle. All the cysts had a narrow channel at their distal extremity which communicated with the femorotibial joint. The more recently developed ones were fluid filled and contained fibrous st...
Civello ANE, Dunkel B, Summers BA, Martineau HM.A neurofibroma of granular cell subtype is described in a 7-year-old horse. The horse had a 3-month history of ataxia affecting the forelimbs and hindlimbs, suggesting a C1-C6 neuroanatomical localization. Post-mortem examination revealed an intradural mass arising from the right sixth cervical spinal nerve and compressing the spinal cord. Histologically, the mass was composed largely of wavy spindle cells (a mixture of Schwann cells, perineurial cells and fibroblasts) intimately associated with ropy collagen fibres. Approximately 25% of the spindle cells were swollen and contained densely-pac...
Zapf AM, Fey K, Büttner K, Gröf M, Staszyk C.Pituitary pars intermedia dysfunction (PPID) and dental disorders are of major concern in horses older than 15 years. Although PPID in geriatric horses and dental disorders in all age groups are well described, a connection between this endocrine disease and pathological changes in equine dental structures has not yet been investigated. In humans, periodontitis is considered to be a complication of systemic diseases like diabetes mellitus type 2, obesity and various conditions leading to an impaired immune response. In PPID, cross links to insulin and immune dysregulations are proven. The aim ...
Sánchez J, Gonzalo-Orden JM, Ginja MM, Oliveira PA, Reyes LE, Serantes AE, Orden MA.An Andalusian Stallion with left hind limb lameness had a radiolucent lesion in the medullary cavity of distal tibial metaphysis. After euthanasia for other disease, the tibia was examined with magnetic resonance (MR). The MR imaging sequences were characterized by a double line sign, although showing quite different lesion area intensities. Histologically, the lesion was compatible with medullary infarction being characterized by normal spongy bone, areas of abundant fibrous tissue and numerous necrotic adipocytes in various stages of destruction.
Richardson LE, Wakley GK, Franklin SH.Dorsal displacement of the soft palate is a common cause of upper airway obstruction in racehorses and is of unknown aetiology. To determine whether the palate may displace for structural reasons, knowledge of the normal soft palate is required. The present study aimed to describe, qualitatively and quantitatively, the structure of the normal equine soft palate using histomorphometry. In soft palates from 12 Thoroughbreds, glandular tissue predominated (ca. 40% of total area), located mainly in the rostral and ventral regions. Rostrally, muscles attached to a tendinous aponeurosis located dors...
Todhunter RJ, Freeman KP, Yeager AE, Lust G.This study assessed the effects of postoperative exercise and intra-articular polysulfated glycosaminoglycan (PSGAG) on the repair of osteochondral defects in the carpal joints of ponies. Eighteen ponies with normal carpi had osteochondral defects (mean dimensions 2.4 cm x 0.9 cm) created arthroscopically on the dorsal aspect of the distal articular surface of the radial carpal bone. The ponies were randomized (while balancing for age [range, 2 to 15 years; median, 5.0 years]) to two groups--nine ponies were exercised and nine were stall confined. Beginning at surgery, six ponies in each group...
Han H, Wang A, Liu L, Zhao G, Su J, Wang B, Li Y, Zhang J, Wu B, Sun W, Hu S, Li S, Zhao L, Li X.Most hinnies (female donkey×male horse) and mules (female horse×male donkey) are sterile with few reports of equine fertile hybrids. The main cause of this sterility is thought to be a meiotic block to spermatogenesis and oogenesis. This study compared the developmental features of the testes and a histological analyses of spermatogenesis in a male hinny with those of a normal, fertile stallion and Jack donkey. Hinny testes showed a thicker tunica albuginea, fewer blood vessels and more connective tissue in the testis parenchyma than those of the stallion and Jack donkey. Although the mean n...
Bergmann W, Vernooij JCM, Grinwis GCM, Gröne A.Osteochondrosis dissecans (OCD) of articular process joints (APJs) is involved in cervical vertebral compressive myelopathy (CVM). Biomechanical forces, important in development of OCD, depend on joint conformation. Oval and flat APJ surfaces are considered normal. Objective: To identify and grade gross shape variation of cervical and cranial thoracic APJ surfaces and determine association with histological evidence of osteochondrosis. Methods: Case series. Methods: Eight hundred and four cervical and cranial thoracic APJ surfaces of 30 foals were evaluated for shape(s) and grades, and were co...
Morini M, Peli A, Rinnovati R, Magazzù G, Romagnoli N, Spadari A, Pietra M.Severe equine asthma (EA) syndrome is a chronic obstructive disease characterized by exaggerated contraction, inflammation, and structural alteration of the airways in adult horses, when exposed to airborne molds and particulate material. However, little is known about the relationship between the degree and type of inflammation on one hand, and the severity of the disease and the response to treatment on the other. Furthermore, to date, very few studies evaluate the diagnostic value of histology and immunohistochemical features of endoscopic biopsies on subjects with severe equine asthma. To ...
Malacarne BD, Martins RR, Paz CFR, Alves JVA, Dias LA, Cavalcante MA, Santos AM, Silva AGM, Leise BS, Carvalho AM, Faleiros RR.Although the external conformation of wild horse hooves has been proposed as an ideal model for domesticated modern horses, histological signs of laminitis have been reported among them. With the hypothesis that the lamellar tissue of horses of Iberian origin raised in semi-feral is healthier than those raised in an intensive management system (stall confinement and high-calorie diet intake), the objective was to compare their lamellar tissues. Lamellar tissue samples were taken from the forelimb hoof of eight domesticated Mangalarga Marchador (MM) horses and from six semi-feral Marajoara (MJ)...
Furness MC, Bienzle D, Caswell JL, Delay J, Viel L.Recurrent airway obstruction (RAO) in the horse is a disease characterized by reversible bronchoconstriction and by mucus and neutrophil accumulation in the airways. It has been hypothesized that in horses with RAO, remodeling changes occur that are similar to those described in humans with asthma. Although collagen fibrils are present surrounding normal airways, they are a prominent feature of airway remodeling in human asthma with evidence of enhanced collagen III and I fibril deposition. An immunolabeling method was developed to identify collagen I and III in equine lung and to describe the...
Ono M, Akuzawa H, Nambo Y, Hirano Y, Kimura J, Takemoto S, Nakamura S, Yokota H, Himeno R, Higuchi T, Ohtaki T, Tsumagari S.A three-dimensional internal structure microscopy (3D-ISM) can clarify the anatomical arrangement of internal structures of equine ovaries. In this study, morphological changes of the equine ovary over the first 12 months of life were investigated by 3D-ISM in 59 fillies and by histological analysis in 2 fillies. The weight and volume of the paired ovaries initially decreased from 0 to 1 months to 2 to 3 months of age and then significantly increased at 8 to 12 months of age. The ovulation fossa was first observed around the 3rd month and became evident after the 6th month. The number of folli...
Diana A, Freccero F, Giancola F, Linta N, Pietra M, Luca V, Salamanca G, Cipone M, Chiocchetti R.Ultrasonographic morphometry of wall layers is commonly used in veterinary patients with suspected small intestinal disease, however published studies comparing this method with histopathology in horses are limited. This prospective, methods comparison study compared the qualitative and quantitative characteristics of small intestinal wall layers using ex vivo high-frequency ultrasound versus histopathology in a sample of 16 horses. Transverse section images of duodenum, distal jejunum, and ileum were acquired with a high-frequency linear transducer (7-15 MHz). Transverse histological cryosec...
McGowan CM, McGowan TW, Patterson-Kane JC.The aim of this study was to determine the prevalence of equine polysaccharide storage myopathy (EPSM) in two populations of horses in the UK. Biopsy specimens from 94 horses presented to an abattoir (population 1), and 46 horses with neuromuscular disorders presented to a university referral hospital (population 2) were obtained over a period of 4years. Histological sections were examined by a veterinary pathologist for lesions including abnormal polysaccharide inclusions in myofibres. In population 1, a diagnosis of EPSM was made in 8% and non-specific myopathy in 33% of horses. In populatio...
Doyle DG.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...
Schumacher J, Smith BL, Morgan SJ.A 2-year-old Quarter Horse gelding was examined for torticollis, facial protuberances over the frontal and maxillary sinuses, and persistent nasal discharge unresponsive to antibiotics. Radiograph revealed an osseous mass in the right paranasal sinuses. Histologic examination of the biopsied mass led to a diagnosis of osteoma. The mass was removed surgically in sections from the right frontal and maxillary sinuses through separate bone flaps, and sinuses were irrigated with saline solution for 8 days after surgery. Two weeks after surgery, radiography revealed small osseous opacities in the ri...
Leadbeater JC, Gutierrez-Nibeyro SD, Brown JA.A 13-year-old Morgan gelding was examined for right forelimb lameness and tenosynovitis of the right common carpal sheath of the digital flexor tendons. The horse had moderate right forelimb lameness at the trot and marked effusion of the right common carpal sheath of the digital flexor tendons. Ultrasonographic examination revealed a soft tissue mass within the proximal pouch of the affected tendon sheath, located adjacent to the distal physis of the radius. Cytology and culture of the fluid revealed a sterile, eosinophilic tenosynovitis. Tenoscopic exploration confirmed the presence of a cap...
Brocca G, Centelleghe C, Padoan E, Stoppini R, Giudice C, Castagnaro M, Zappulli V.A 24-year-old Irish Cob mare was presented with a peripheral iris mass, which was surgically resected and diagnosed as an undifferentiated neuroepithelial tumor. A few months later, a relapse occurred with histological features characterized by a more solid appearance and squamous differentiation. Subsequently, the mare was presented with rapidly spreading multiple subcutaneous masses and, at the onset of neurological signs, was humanely euthanized and subjected to a complete post mortem examination. The necropsy confirmed the presence of numerous widespread masses in the subcutaneous tissue, ...
Marshall DE, Dumasia MC, Wooding P, Gower DB, Houghton E.Maternal endometrial and fetal allantochorionic tissues were separated manually from the placentae of seven healthy thoroughbred and three pony mares, ranging in gestational age from 100 to 318 days. The homogeneity of subcellular fractions prepared from these tissues was assessed initially using the marker enzymes, succinate dehydrogenase, NADPH cytochrome C reductase and lactate dehydrogenase for the mitochondrial, microsomal and cytosolic fractions, respectively. Light microscopy and histochemical analysis demonstrated that the separated fetal allantochorionic membrane, which is made up of ...
Marsh AE, Chaney SB, Howe DK, Saville WJ, Reed SM.Several reports indicate the presence of small tissue cysts associated with Sarcocystis neurona infections. Several failed attempts to develop tissue cysts in potential intermediate host using in vitro derived parasites originally isolated from horses with equine protozoal myeloencephalitis suggest that the experimental methods to achieve bradyzoites with those isolates was not possible. Those prior studies reported the lack of detectable sarcocysts based on histology and in vivo feeding trials. A recent report of successful production and detection of small sarcocysts triggered us to review a...
Van Hoogmoed LM, Agnew DW, Whitcomb M, Hyde DW, MacDonald MH, Snyder JR.To describe the ultrasonographic and quantitative histologic effect of injecting 2% iodine in almond oil (IAO) and ethanolamine oleate (EO) in the medial and middle patellar ligaments of horses and to determine whether a difference in response exists between IAO and EO treatment. Methods: 10 healthy horses. Methods: In 5 horses, the medial and middle patellar ligaments of 1 limb were injected with EO, whereas IAO was injected in the medial and middle patellar ligaments of another 5 horses. Ultrasonographic evaluation was performed on the experimental and control limb before injection of IAO an...
Kim TI, Chung CP, Heo MS, Park YJ, Rhee SH.This study was performed to evaluate the periodontal wound healing effect of particulate equine bone mineral on canine alveolar bone defects. Methods: Twelve adult male beagle dogs were used as study subjects. The mandibular second and fourth premolars were extracted prior to the experimental surgery, and the extraction sites were allowed to heal for 8 weeks. After periodontal probing, two-walled defects were created at the mesial and distal sides of the mandibular third premolars bilaterally, and the defects were filled with equine particulate bone with collagen membrane or bovine particulate...
Kobluk CN, Smith DF.An intramural hematoma involving a 40-cm segment of the distal portion of the jejunum caused intestinal obstruction and colic in a mature mare. The involved intestine was resected, and an end-to-end anastomosis was performed. The mare recovered completely, but 4 years later had colic caused by incarceration and volvulus of the distal portion of the jejunum, involving fibrous abdominal adhesions. The cause of hematoma was not identified; however, rupture of an intramural vessel after migration of Strongylus vulgaris larvae was considered a possibility because of the histologic observation of an...
Muylle S, Simoens P, Lauwers H.The distribution of intratubular (peritubular) dentine was studied by scanning electron microscopy in 12 equine incisor teeth. High levels of intratubular dentine were found in the peripheral regions of the dentine. In these areas, a marked asymmetry occurred, as intratubular dentine was predominantly deposited onto the side of the dentinal tubular walls nearest to the dentino-enamel junction. The quantity and asymmetry of intratubular dentine were reduced towards the centre of the tooth. The significance of these variations in the amount and distribution of intratubular dentine between the di...
Vlaminck L, Cnudde V, Pieters K, Van Den Broeck W, Steenhaut M, Jacobs P, Gasthuys F.To evaluate the biological behavior of a nonresorbable bone substitute (NRBS) in the alveoli of ponies, compared with tissue quality in naturally healing alveoli, after cheek tooth extraction. Methods: 5 clinically normal ponies. Methods: In each pony, both maxillary fourth premolars (Triadan 108/208) were repulsed bilaterally during anesthesia. One randomly chosen alveolus was filled with NRBS and isolated from the oral cavity by use of dental impression material and a spring-wire retention device. The other alveolus was occluded in its occlusal third portion with dental impression material. ...
Mouguelar H, Díaz T, Borghi D, Quinteros R, Bonino F, Apichela SA, Aguilar JJ.The objectives of this work were to describe some morphometric characteristics and to establish quantitative parameters of different regions of the equine oviductal mucosa from the isthmus, ampullary-isthmic junction (AIJ), and ampulla. Twenty-one mixed-bred mares were used for this study. Mares were selected in the following reproductive phases: anestrus, estrus, and diestrus. The left oviducts were examined with light microscopy, and rights ones were studied through the intraoviductal molds. The isthmus showed the smallest luminal area, mucosal area, epithelial perimeter, and luminal diamete...
Hodgson DR, Rose RJ, Allen JR, Dimauro J.Muscle biopsy samples were collected from the left middle gluteal muscle of the horses participating in day 2 (speed and endurance test) of a three day event. Six Thoroughbred horses were biopsied the day before and within 30 minutes of completion of the speed and endurance test. Serial muscle sections were reacted histochemically for myosin adenosine triphosphatase activity after acid pre-incubation to demonstrate Type I, IIA and IIB fibers and the glycogen content in the individual fibers was assessed using the periodic acid Schiff (PAS) reaction. Total glycogen in muscle was measured fluoro...
