Pathology in horses involves the study of diseases and abnormalities affecting equine health, encompassing a range of conditions that can impact various systems within the horse's body. This field examines the causes, mechanisms, and effects of diseases, as well as the structural and functional changes they induce in equine tissues and organs. Common pathological conditions in horses include laminitis, colic, equine infectious anemia, and respiratory disorders. Understanding these diseases involves evaluating clinical signs, diagnostic methods, and treatment options. This page compiles peer-reviewed research studies and scholarly articles that explore the etiology, pathogenesis, and clinical implications of pathological conditions in horses.
Oki Y, Miura K.In the recent years, various red cell auto-antibodies have been determined in someanimal diseases, including autoimmune hemolytic anemia and systemic lupus erythe-matosus in dogs, ") Aleutian disease in minks, 8) and equine infectious anemia."?">In this report, the red cell auto-antibodies were examined for symptomatiCchanges, serological characteristics, and immunopathological roles in 20 horses infectedwith equine infectious anemia virus (Table l).Pathologic cold hemagglutiuain and warm hemagglutinin were identified in theplasma of artificially infected horses. The direct antiglobulin tests ...
Fransson LA, Havsmark B.The structure of dermatan sulfate-chondroitin sulfate
copolymers, isolated from horse aorta, has been examined.
It was found that a large proportion of the galactosaminoglycans of this tissue was obtained as a discrete polysaccharide fraction with an L-iduronic acid to D-glucuronic
acid ratio of approximately 1: 2. This finding together with
infrared data indicated that the polymer contained approximately equimolar proportions of the three repeating disaccharide units glucuronosyl-N-acetylgalactosamine 4-sulfate
(A), iduronosyl-N-acetylgalactosamine 4-sulfate (B), and
glucuronosyl-N-acet...
Taylor AW.The possible sequelae of traumatic perforation
of the reticulum of cattle are described by Blood
and Henderson (1963). Traumatic splenitis and
hepatitis following perforation of the reticulum
have also been described in detail (Blood and
Hutchins 1955).
Frank (1959) described and illustrated both
thrombus formation and stricture of the posterior
vena cava following traumatic reticulitis with subsequent abscess formation. The proximity of the
abscess to the posterior vena cava apparently
caused erosion of the vessel wall, and the inflammatory reaction initiated the formation of a
thr...
Fulton RE, Doane FW, Macpherson LW.Combined light and electron microscopy were used to follow the sequence of virus development in equine papillomas. The deepest layer in which virus was observed was the stratum spinosum of the epidermis. In this layer virus was scattered throughout the nuclei and was occasionally found in association with the nucleolus. In the stratum granulosum virus particles were more numerous, often forming isolated nuclear aggregates. Virus inclusions observed in the stratum granulosum by electron microscopy were correlated with nuclear inclusions seen by light microscopy. In the stratum corneum closely p...
de Oliveira AC, Rosenbruch M, Schulz LC.The morphology of asteroid bodies in equine arteries is demonstrated by light microscopy as well as by scanning and transmission electron microscopy combined with chemical analysis. Asteroid bodies first occur in horses at four weeks of age in all investigated tissues except the esophagus and always are located in the subendothelial space. The number, shape, ultrastructure and chemical composition of asteroid bodies differ markedly--depending on the age of the horse. Asteroid bodies are round and smooth in foals, but are shaped irregularly and have several projections and marked stratified cal...
Herdan CL, Nicholson CL, Firth EC.The third carpal bone (C3) responds to exercise by adaptive modeling of bone and articular calcified cartilage along the dorsal load path. Canals penetrating articular calcified cartilage, thought to contain vascular tissue, are reported in numerous species. Their significance remains unclear. Our objective was to determine if the number of canals was significantly different in strenuously exercised and control young horses and in a site of intermittent high loading compared to sites sustaining lower habitual loads. Volumetric bone mineral density in the radial facet of C3 of strenuously exerc...
Pye J, Kilcoyne I, Roy M, Vaughan B, Ormond C, Spriet M.A 20-year-old Quarter horse gelding was referred for evaluation of an acute onset non-weight-bearing right forelimb lameness. Marked soft tissue swelling was apparent over the right scapula and shoulder region; no crepitus was palpable. A complete transverse fracture of the scapular neck was suspected based on ultrasonography and radiographs were obtained to confirm the presumptive diagnosis. A complete, oblique fracture of the right scapular neck with mild cranial and proximal displacement of the distal fragment was detected. Computed tomography of the upper right forelimb was performed post-...
Rossdale PD, Jeffcott LB, Leadon DP.The development and design of a project in collaborative research which originated from a problem identified in practice, namely prematurity in the newly born foal, is described here. The project established a model of equine prematurity for the purpose of studying the diagnosis, pathogenesis and treatment of the condition. It involved practitioners and full time research workers in a number of veterinary and medical institutes.
Scott DW, Walton DK, Smith CA, Lewis RM.Indirect immunofluorescence testing for pemphigus-like antibodies was performed on 79 horses: 28 horses with various nonpemphigus dermatologic diseases, 21 horses with various nondermatologic diseases, and 30 normal horses. Pemphigus-like antibodies were detected in 6 horses: 3 normal horses with titers of 1:40, 2 horses with dermatophilosis at titers of 1:10 and 1:80, and 1 horse with lymphosarcoma at a titer of 1:320. It was concluded that equine pemphigus-like antibodies are a potential source of misinterpretation and misdiagnosis in indirect immunofluorescence testing. Direct immunofluores...
Rejnö S.Synovial fluid samples from 51 light horses were examined with respect to their rhéologie properties. The analyses were made with a Rotovisco RV3 rotational viscosimeter. Samples from carpal, stifle and hock joints and from healthy joints, joints with synovitis and joints with infectious arthritis were studied. The analyses showed that synovial fluids from both healthy and diseased joints have complex rhéologie properties. In most samples the viscosity varied with the shear rates, the main exceptions being synovial fluids from joints with infectious arthritis. Flow curves (flow behaviour), r...
Schoenborn WC, Rick MC, Hornof WJ.A 6-year-old Thoroughbred gelding presented with a left forelimb lameness. The results of lameness examination, radiography, nuclear scintigraphy, and computed tomography are presented. Based on the diagnostic imaging, subchondral fractures and osteochondritis dissecans lesions of the proximal articular surface of the proximal phalanx were diagnosed. A brief discussion of osteochondritis dissecans is presented.
Harmel JL, Lewis CW, Sah RL, Kawcak CE, Wheeler DL.Millions of Americans suffer from osteoarthritis, a joint disease characterized by cartilage degradation and subchondral bone sclerosis. However, little is known about its pathology. It remains to be discovered which comes first in the progression of osteoarthritis: subchondral bone remodeling or cartilage degeneration. This study assessed equine cartilage degeneration, based upon measurements of cartilage thickness and Indian ink stain uptake. By gaining a greater understanding of the determining factors in cartilage degeneration, we may be able to better understand the pathomechanics of oste...
Underwood C, Collins SN, Mills PC, Van Eps AW, Allavena RE, Medina Torres CE, Pollitt CC.Pharmaceutical agents with potential for laminitis prevention have been identified. Many of these, including the MMP inhibitor marimastat, are impractical for systemic administration. This study compared local delivery of marimastat by regional limb perfusion (RLP) to systemic intravenous bolus dosing (SIVB), and established whether RLP results in local lamellar drug delivery. Six adult horses received 0.23 mg/kg of marimastat by RLP followed by 0.23 mg/kg marimastat by SIVB, with a 24-h washout period. Lamellar ultrafiltration probes sampled lamellar interstitial fluid as lamellar ultrafiltra...
Erridge ME, Cox AL, Dixon PM.Peripheral caries of equine cheek teeth is a poorly described disorder and, in particular little is known of its histopathology. Histological examinations of decalcified sections of 21 equine peripheral caries-affected cheek teeth showed two different patterns of cemental lesions; including progressive enlargement of focal, flask-like lesions leading to breakdown of the adjacent cementum, and secondly; a more generalized flaking-off of thin layers of under-run, surface cementum. A thick layer of plaque and food material usually lay on the surface of affected cementum and also within cemental d...
Taylor BM, Chaffin MK, Hoffmann AR, Edwards JF, Arenas-Gamboa AM.Prolonged exposure to water, known as immersion foot syndrome in humans, is a phenomenon first described in soldiers during World War I and characterized by dermal ischemic necrosis. In this report, we describe the pathologic findings of a condition resembling immersion foot syndrome in 5 horses and 1 donkey with prolonged floodwater exposure during Hurricane Harvey. At necropsy, all animals had dermal defects ventral to a sharply demarcated "water line" along the lateral trunk. In 5 animals, histologic examination revealed moderate to severe perivascular dermatitis with vasculitis and coagula...
Komosa M, Włodarek J, Dzierzęcka M, Nienartowicz-Zdrojewska A, Tołkacz M.The problem of navicular bone lesions is better understood in warmblood horses. The aim of our research was to compare pathologic lesions of navicular bone of different types of horses divided into age groups. An extra goal was to compare radiographs with anatomical status of navicular bone dissected from the hoof capsule. The study group included 161 horses, out of which 100 individuals were warmbloods, and 61 - coldbloods. In total 280 navicular bones were analysed. The flexor surface, distal border fragments, enthesophytes and the process of obliteration of nutrient foramina were analysed. ...
Vidović A, Jansen D, Hermeyer K.A 2-year-old Arabian horse was presented with severe colic symptoms. During explorative laparotomy, a jejuno-jejunal invagination secondary to a submucosal intestinal mass was detected. The involved jejunal segment was surgically removed and an end-to-end anastomosis was created. Opening the specimen demonstrated the presence of a nodular mass on the head of the intussusceptum, measuring 10 cm in diameter, and almost completely obliterating the intestinal lumen. Additionally, a severe hyperemia of the jejunal mucosa was visible. Histological examination, which revealed a well-demarcated mass...
Hellige M, Warnken T, Puff C, Feige K.An 8-year-old Warmblood gelding presented with a history of progressive ataxia for 6 weeks. Intra- and intervertebral ratios measured from lateral radiographs of the cervical spine were within normal limits. Computed tomographic myelography of the cervical spine revealed focal compression of the dorsal and the ventral contrast column as well as a ventral displacement of the spinal cord within the spinal canal due to a bulging of soft tissue attenuating material in the dorsal half of the intervertebral junction of C6 and C7. Post-mortem histopathological examination confirmed chondroid metapla...
Jean D, Lavoie JP, Nunez L, Lagacé A, Laverty S.A 6-year-old Thoroughbred mare had a 7-cm ulcerated mass on the cranial aspect of the left cervical area. Ultrasonography revealed the mass to be < 1 cm thick and composed of small lobules that were filled by material hypoechoic to the surrounding muscle tissues. Fine-needle aspiration of the mass yielded blood, and cytologic examination revealed a few epithelial cells with neoplastic changes. Thoracic radiography revealed an interstitial pattern with several disseminated nodules. A diagnosis of cutaneous hemangiosarcoma with pulmonary metastases was made. The diagnosis was confirmed at necrop...
Dagleish MP, Pemberton AD, Brazil TJ, McAleese SM, Miller HR, Scudamore CL.Man and horses both suffer from neutrophil mediated pulmonary diseases however there are striking species differences in the underlying pathology. In particular while pulmonary emphysema is a common pathological sequel to human respiratory disease it is not a major feature of the common equine neutrophil mediated condition, chronic obstructive pulmonary disease (COPD). The proposed reason for this difference is that equine neutrophils contain less elastase than equivalent human cells and therefore there is a reduced risk of excess and/or uninhibited elastase activity, which is considered the m...
White SD, Foley JE, Spiegel IB, Ihrke PJ.Equine sarcoidosis is a rare, multisystemic, noncaseating, granulomatous and lymphoplasmacytic disease of unknown etiology. A recent report described a horse with granulomatous skin disease displaying histologic, electron microscopic, and polymerase chain reaction (PCR) findings consistent with equine herpesvirus 2 (EHV-2). Objective: To investigate the presence of EHV-2 and equine herpesvirus 1 (EHV-1) in 8 horses with sarcoidosis. Methods: Eight horses with sarcoidosis, reported previously. Methods: Retrospective study. PCR assays of the tissues were performed to detect DNA associated with E...
Leidl W.1. At present there is a wide field of applications for ultrasonography in gynaecological examinations. 2. Pregnancy (under clinical conditions) may be diagnosed in mares from day 14, in cows from day 25/26, in small ruminants from day 35, in sows from day 28/30, in bitches from day 25/28 and in queens from day 20/25 on, either by demonstrating the embryonic vesicle or the embryo or fetus. 3. Control of ovulation is gaining importance in the mare, especially in artificial insemination. 4. The diagnosis of pathological processes in the uterus of mares, bitches and queens is improved considerabl...
Haughey KG, Jones RT.A high frequency of meningeal lesions was found at autopsy in foals dying perinatally. Such lesions are considered an index of injury to the fetal central nervous system, from trauma and/or hypoxia during birth. Their incidence in the sample examined (26 foals) is similar to that observed in the perinatal mortality of lambs and calves.
Lubczyk B, Nothelfer HB.A case of generalized equine leucosis is presented. The most important clinical signs were cachexia, loss of condition, fever, tachycardia, subcutaneous tumors and severe lameness accompanied by edema of the right thoracic limb. Hematology showed anemia and neutrophilia; clinical biochemistry indicated hypalbuminemia, hyperphosphatemia and hyperfibrinogenemia. Necropsy revealed multiple tumors throughout the body which mainly originated from lymph nodes. Histopathologically the tumors consisted of two cell-types: a. uniform lymphocytoid cells with a highly infiltrative growth pattern; b. heter...
Cheramie HS, Pleasant RS, Robertson JL, Moll HD, Carrig CB, Freeman DE, Jensen ME.To evaluate an occlusion technique for the internal carotid artery of horses using an intravascular, detachable, self-sealing, latex balloon distally and ligatures proximally. Methods: Experimental study. Methods: Six healthy adult horses. Methods: In each horse, the left internal carotid artery was occluded by placement of an intravascular, detachable, self-sealing, latex balloon distally and two ligatures proximally. Radiographs were taken on days 2, 5, 10, and 30 after surgery to evaluate balloon inflation and position. Endoscopic examination of the left guttural pouch was performed 10 days...
Beard WL, Lohse CL, Robertson JT.The blood supply to the descending colon of the horse was studied by gross dissection and methyl methacrylate corrosion casts. The arterial supply is derived from the left colic artery and cranial rectal artery with the left colic artery supplying approximately the proximal three fourths. Each artery gives off four to eight arcuate arteries that form a series of anastomosing arcades. The arcade pattern continues to form a marginal artery that parallels the long axis of the colon. Small branches from the marginal artery anastomose with adjacent branches to form a secondary arcade. The secondary...
Dart AJ, Snyder JR, Harmon FA.The microvascular circulation of the descending colon was studied in 5 adult horses, using microangiography and light microscopy combined with gross studies and scanning electron microscopy of vascular replicas. After heparinization, horses were euthanatized, and 3 segments of the descending colon and its mesentery containing 1 vascular arcade were removed from each horse. The fecal balls were gently massaged from the lumen, and the blood was flushed free of the circulation with isotonic NaCl. In 5 segments, the vascular system was injected with a modified radiopaque medium and evaluated radio...
Kempson SA, Campbell EH.The permeability barrier in the dorsal wall of the equine hoof capsule was studied by means of horseradish peroxidase (HRP) in 0.9 N saline solution as a water soluble tracer. Section were treated with 3'3'-diaminobenzidine tetrachloride (DAB) and before dissection the quality of the horn of feet from 10 horses was assessed and given a subjective grade as either good or poor. Blocks of tissue from each horse were left in either an oven at 60 degrees C or in water for 2 weeks before treatment in HRP, sectioning and DAB solution. Regions observed were i) outer surface, ii) outermost layers of th...
Ochi A, Nishioka T, Kurimoto S, Kishi D, Ueno T, Nukada T.A 2-year-old male Thoroughbred horse presented with a mass in the maxilla. The focally ulcerated mass, approximately 8 cm in diameter, covered the upper left intermediate and corner incisor teeth (nos. 602 and 603 according to the modified Triadan system) and radiographic examination revealed displacement and lysis of the incisors. Histologically, the tumour was composed of a dense proliferation of spindle-shaped cells and neoplastic odontogenic epithelial cells arranged in island, follicular, plexiform or sheetlike patterns. The spindle-shaped cells were immunopositive for cytokeratins AE1/A...
Mair TS, Stokes CR, Bourne FJ.The immunoglobulin (Ig) content of serum and tracheal lavage fluid was measured in 50 horses suffering from chronic obstructive pulmonary disease (COPD) and 40 control horses. The mean immunoglobulin: albumin ratios of the lavage fluids of both groups were significantly higher than the corresponding values for serum, which indicates significant local production of immunoglobulins in the lower respiratory tract. The IgA: albumin ratio of lavage fluid was significantly higher in diseased compared with normal horses, which implies increased local production of IgA in this disease. The IgG: albumi...
Kamalov AA, Gukhikh GT, Kirpatovskiĭ VI, Zaraĭskiĭ EI, Poltavtseva RA, Plotnikov EIu, Kudriavtsev IuV, Efremov EA, Obokhotov DA.The study of cell cultures enriched with stem and progenitor cells in the treatment of experimental hypergonadotropic hypogonadism was made on 30 white non-inbred rats with experimental cryptorchism who have undergone xenotransplantation of human fetal enriched cell cultures. Spermatogenic epithelium on histological sections was studied on day 14 and 28 after xenotransplantation with calculation of the spermatogenesis index. The fertility index was estimated for each of the groups. Transplantation of enriched cell cultures enhances efficacy of restoration of adequate germinogenic and spermatog...
Flieger S, Sławomirski J, Boratyński Z, Jastrzebski M.Two medullae oblongatae of horses were cut into 15 microns cross-sections and stained according to the modified method of Nissel. The lateral motor nucleus lies in the lateral and median part of the ventral column of spinal cord grey matter. It adjoins medially nucleus motorius medialis of the spinal ventral column. Cells of this nucleus occur both along the whole lumbar and sacral segment of the spinal cord. In the lateral motor nucleus three cell groups are distinguished-median, basal and lateral. The latter is divided in some segments into subgroups-dorsal and ventral. Along the nucleus qui...
Rose PL, Hightower D, Auer JA, Hulse D, Schenk RK.In the present study, radionuclide scintigraphy and radiography were used to evaluate the rate and degree of healing that occurred in surgically created subchondral bone defects in horses. Following radionuclide scintigraphy and radiography the horses were killed, and histomorphometric analysis was performed on the defect sites. The histomorphometric results were compared to the radionuclide scintigraphic and radiographic results to determine which noninvasive technique provided the most accurate information concerning healing of the bone defects. It was concluded that radionuclide scintigraph...
De Paolis L, Armando F, Montemurro V, Petrizzi L, Straticò P, Mecocci S, Guarnieri C, Pezzolato M, Fruscione F, Passeri B, Marruchella G, Razzuoli E.Vulvar squamous cell carcinoma (VSCC) has been recently associated with Equus caballus papillomavirus type 2 (EcPV2) infection. Still, few reports concerning this disease are present in the literature. Objective: To describe a case of naturally occurring EcPV2-induced VSCC, by investigating tumour ability in undergoing the epithelial-to-mesenchymal transition (EMT). Methods: Case report. Methods: A 13-year-old Haflinger mare was referred for a rapidly growing vulvar mass. After surgical excision, the mass was submitted to histopathology and molecular analysis. Histopathological diagnosis was c...
