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.
Rocchigiani G, Verin R, Uzal FA, Singer ER, Pregel P, Ressel L, Ricci E.Exercise-induced pulmonary hemorrhage (EIPH) is a common condition of Thoroughbred racehorses that is usually responsible for reduced performance, while exercise-associated fatal pulmonary hemorrhage (EAFPH) is characterized by severe pulmonary bleeding of unknown pathogenesis resulting in sudden death during strenuous exercise. The aim of the study was to characterize and compare anamnestic data together with pulmonary gross, histologic, and ultrastructural findings in racehorses with EIPH (n = 10), EAFPH (n = 10), and control horses (n = 5). No differences in anamnesis were identified betwee...
Alpoim-Moreira J, Fernandes C, Pimenta J, Bliebernicht M, Rebordão MR, Castelo-Branco P, Szóstek-Mioduchowska A, Skarzynski DJ, Ferreira-Dias G.Endometrium type I (COL1) and III (COL3) collagen accumulation, periglandular fibrosis and mare infertility characterize endometrosis. Metalloproteinase-2 (MMP-2), MMP-9 and tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) are involved in collagen turnover. Since epigenetic changes may control fibroproliferative diseases, we hypothesized that epigenetic mechanisms could modulate equine endometrosis. Epigenetic changes can be reversed and therefore extremely promising for therapeutic use. Methylation pattern analysis of a particular gene zone is used to detect epigenetic changes. DNA...
Gunsalus K, Taylor R, Croix N.To report the clinical history, surgical management, and histologic findings of meibomian gland calcification and osseous metaplasia in a horse. Methods: A 21-year-old Selle Français gelding presented with a 9 months history of blepharitis, blepharospasm, and epiphora affecting the right eye. The horse was diagnosed with meibomianitis and impaction with associated granulomas, but not treated surgically for 6 years. Methods: Physical and ophthalmic examinations, and systemic bloodwork were performed. A diamond burr debridement was performed on a corneal ulceration, and meibomian gland nodul...
Handschuh S, Okada CTC, Walter I, Aurich C, Glösmann M.Here, we describe a workflow for high-detail microCT imaging of formalin-fixed and paraffin-embedded (FFPE) equine embryos recovered on Day 34 of pregnancy (E34), a period just before placenta formation. The presented imaging methods are suitable for large animals' embryos with intention to study morphological and developmental aspects, but more generally can be adopted for all kinds of FFPE tissue specimens. Microscopic 3D imaging techniques such as microCT are important tools for detecting and studying normal embryogenesis and developmental disorders. To date, microCT imaging of vertebrate e...
Albers L, Bienert-Zeit A, Staszyk C.Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) and other incisor lesions are often diagnosed only in advanced stages. The incisors of 20 horses were examined radiographically, macroscopically, and via micro-computed tomography (µCT) to discriminate EORTH-affected teeth. Five categories from healthy to severely affected teeth were formed and teeth from each category were examined histologically to evaluate the opportunity of earlier radiographic diagnosis. Histologically, odontoclastic resorptive lesions, leukocytic infiltrations, and areas of irregular cementum and granulat...
Senderska-Płonowska M, Siwińska N, Zak-Bochenek A, Rykała M, Słowikowska M, Madej JP, Kaleta-Kuratewicz K, Niedźwiedź A.Obesity is a common problem in horses. The associations between obesity and equine metabolic syndrome (EMS) and between EMS and laminitis are known. However, there is a lack of data on whether obesity itself can affect hoof lamellae. Forelimbs and blood from 12 draft horses (six obese and six lean) from a slaughterhouse were acquired. To exclude laminitis and EMS horses, insulin concentration was measured, and hooves were radiographed. Histological evaluation was performed. The shape of the primary and secondary epidermal lamellae (PEL and SEL) was evaluated, and the length of the keratinized ...
Finno CJ, Johnson AL.Neuroaxonal degenerative disease in the horse is termed equine neuroaxonal dystrophy (eNAD), when pathologic lesions are localized to the brainstem and equine degenerative myeloencephalopathy (EDM) and degenerative changes extend throughout the spinal cord. Both pathologic conditions result in identical clinical disease, most commonly characterized by the insidious onset of ataxia during early development. However, later onset of clinical signs and additional clinical features, such as behavior changes, is also observed. A definitive diagnosis of eNAD/EDM requires histologic evaluation of the ...
Doll CU, von Pueckler K, Offhaus J, Berner D, Burk J.In equine medicine, experience regarding MRI of chronic tendon lesions is limited, and evidence on the suitability of different sequences in 3 T high-field MRI is scarce. Therefore, macroscopically healthy and altered tendons were examined by histology and in 0.27 T low- and 3 T high-field MRI, focusing on T1-weighted (T1w) sequences to visualize chronic lesions. In high-field MRI, tendons were positioned parallel (horizontal) and perpendicular (vertical) to the magnetic field, acknowledging the possible impact of the magic angle effect. The images were evaluated qualitatively and signal inten...
Luedke LK, Ilevbare P, Noordwijk KJ, Palomino PM, McDonough SP, Palmer SE, Basran PS, Donnelly E, Reesink HL.To determine whether proximal sesamoid bone (PSB) microdamage and fracture toughness differ between Thoroughbred racehorses sustaining PSB fracture and controls. Methods: Cadaveric case-control. Methods: Twenty-four Thoroughbred racehorses (n = 12 PSB fracture, n = 12 control). Methods: Proximal sesamoid bones were dissected, and gross pathological changes and morphological measurements were documented. High-speed exercise history data were evaluated. Microdamage was assessed in fracture, fracture-contralateral limb (FXCL) and control PSBs using whole bone lead uranyl acetate (LUA) stainin...
Löfgren M, Ekman S, Ekholm J, Engström M, Fjordbakk CT, Svala E, Holm Forsström K, Lindahl A, Skiöldebrand E.Autologous conditioned serum (ACS) is used to treat osteoarthritis in horses, although its effects are not fully investigated. Objective: To investigate the effects of equine serum and conditioned serum on chondrocytes stimulated with interleukin (IL)-1β and cartilage explants with mild osteoarthritis. Methods: In vitro experimental study. Methods: The effect of three different serum preparations (unincubated control [PS], serum incubated 24 h [PS24h] and serum incubated 24 h in ACS containers [PCS]) pooled from lame horses were tested in two in vitro models. IL-1β and IL-1 receptor anta...
Sykes CA, Uzal FA, Mete A, Ochoa J, Filigenzi M, Poppenga RH, Asin J.A presumptive postmortem diagnosis of oleander () poisoning is made based on the histological observation of cardiomyocyte degeneration and necrosis, which is considered to be a reliable diagnostic marker, and can be confirmed via the detection of oleandrin in tissues or fluids. However, cardiac lesions may not be present in every case, and autolysis can often preclude the identification of subtle changes in the cardiomyocytes. Several studies of experimental oleander poisoning have noted the presence of renal lesions in multiple mammalian species, and case studies of accidental exposure have ...
Roßgardt J, Heilen LB, Büttner K, Dern-Wieloch J, Vogelsberg J, Staszyk C.To maintain a healthy and functional status, equine hypsodont teeth have to produce lifelong large amounts of subocclusal dentin to prevent occlusal pulp exposure, which is caused by occlusal wear. To examine the cyto- and histological components that guarantee the lifelong high productivity of equine pulp, a limited number of ten incisors and ten cheek teeth from seven adult horses (aged 5 to 24 years) and five foals were sampled for preliminary histomorphometric and histomorphological evaluations. Independently of age, the equine dental pulp featured constant layers of predentin and odontobl...
Sokołowska J, Cywińska A, Puchalska M.The number, morphology, and distribution of C thyrocytes within the thyroid gland vary among species; however, studies in domestic animals are limited. In this study we compared the morphology, distribution pattern, and percentage of C thyrocytes in four domestic species: dogs, pigs, horses, and cattle. Eighty thyroid glands, 20 per species, were examined. C thyrocytes were visualized immunohistochemically with anti-calcitonin rabbit polyclonal antibody alone and combined with the periodic acid Schiff method to simultaneously visualize C thyrocytes with the basement membranes of thyroid follic...
Botha AE, Schulman ML, Birrell J, du Plessis L, Laver PN, Soley J, Colenbrander B, Bertschinger HJ.The effects of the GnRH vaccine Improvac on testicular and epididymal morphometrics, histology and spermatogenesis were measured in 19 young (15-20 months) colts randomly assigned to one control (saline, castration at 57 days, n = 6) or either of two GnRH vaccine-treatment groups, T-57 (castration at 57 days, n = 7) or T-100 (castration at 100 days, n = 6), respectively. All were immunized on Day 0 with a single booster on Day 28. Excised testes and epididymides were weighed and processed for histology to measure tubule, epithelial and muscle dimensions, the ratio of interstitial tis...
Attaai AH, Hussein MT, Aly KH, Abdel-Maksoud FM.The donkey is mainly used as a working animal for riding and pack transport, as well as for dairy and meat production. Eye afflictions are common in donkeys, thus requiring a detailed study. A few studies had focused on the donkey's eye, and most of them had considered it, merely, a horse's eye. This study aimed to investigate the anatomy, histology, ultrastructure, and immunohistochemical features of the donkey's eye. The results were recorded and compared to those of horses in certain dimensions. Unlike horses, the donkey's eye is more circular in the contour of the cornea, has smaller lenti...
Harada K, Kanemitsu S, Akioka K, Fujita K, Nishi Y, Taura Y, Sasaki N.Fifty-four slaughtered horses were classified into groups having adipose tissue in the crest of the neck with or without hemorrhage (AH and NH groups, respectively). Blood biochemical tests (Alb, TP, T-bil, GOT, GPT, LDH, T-cho, and BUN) and an epidemiological survey (age, gender, weight, origin, breed, BCS, CNS, and hoof disease) were performed. T-bil tended to be high, while the other parameters were normal. Weight, BCS, and CNS were higher in the AH group (P<0.05). GOT was lower in the AH group (P<0.05). It was suspected that the horses in the AH group had lipomatosis. It was assumed ...
Ferreira C, Palhares MS, de Melo UP, Chiarini-Garcia H, Maranhão RPA, Gheller VA, Leme FOP.To determine the effect of the inclusion method on the histomorphometric evaluation of the gastrointestinal mucosa of horses, jejunum samples were collected using flank laparotomy. Sixteen mixed breed healthy adult horses, including four males and 12 females, aged 4-14 years with an average body weight of 248.40 ± 2.28 kg, were used. Jejunal biopsies were collected and analyzed by light microscopy using two methods: group 1 comprised biopsies fixed using 10% neutral formalin and embedded in paraffin; biopsies in group 2 were fixed in 2.5% glutaraldehyde in 0.1 M phosphate buffer pH 7.2, follo...
Andersen C, Griffin JF, Jacobsen S, Østergaard S, Walters M, Mori Y, Lindegaard C.Articular cartilage thinning is an important hallmark of osteoarthritis (OA), and ultrasonography (US) is a clinically accessible tool potentially suitable for repeated evaluation. The aim of the present prospective methods comparison study was to validate US as a tool for measuring cartilage thickness in the carpus of the horse. Eight Standardbred trotters underwent US examination with 9 and 15 MHz linear transducers. Six anatomical locations in the radiocarpal joint (RCJ) and middle carpal joint (MCJ) were examined. The same joints were assessed by ultrahigh field (9.4 Tesla) magnetic reson...
Mureşan A, Mureşan C, Siteavu M, Avram E, Bochynska D, Taulescu M.Equine herpesviruses are important pathogens causing significant economic loss in equine and asinine populations. EHV-1/4 strains are mainly associated with respiratory distress. The aim of this study is to report the first EHV 4-associated respiratory disease in donkeys in Romania. Thirty-seven of three hundred jennies in an ecological donkey farm in southwest Romania started initially showing signs of severe upper respiratory tract disease, with ten concomitant late abortions/neonatal deaths and three neurological cases. There were nine fatalities. Pathological examination was performed, and...
Köhne M, Unruh C, Böttcher D, Tönissen A, Ulrich R, Sieme H.Uterine pathologies are the most common causes of infertility in mares. This study aimed to establish an ex vivo blood-perfused model for equine uteri and investigate the possible effects of different cycle stages (estrus, diestrus and anestrus) on the applicability of the model. Uteri (n = 13) were collected at an abattoir, flushed with preservation solution, transported to the laboratory on ice, and isolated perfused with autologous blood for 6 h (n = 12). For negative control, one uterus was handled as described but left without perfusion for 6 h. The cycle stage was determined by ex...
Herb VM, Url A, Tichy A, Nell B.Establishing an immunohistochemical approach for semi-quantitative assessment of the presence of immunoglobulin G (IgG) in equine, canine, and feline corneas. Methods: Healthy corneas of horses, dogs, and cats, euthanized because of a fatal disease or an unrecoverable trauma unrelated to and without a history of ophthalmic disease were formalin-fixed, paraffin-embedded, and determined to be pathomorphologically healthy by light microscopy. Automated immunohistochemistry was performed using primary antibodies against IgG, biotin-conjugated secondary antibodies, and streptavidin-peroxidase, as w...
José Antonio G, Jim S, Ramés SJ, Rohrbach BW, Alejandro Rodríguez M, Laura Romero R, Robert D.To examine changes occurring in normal pelvic suspensory ligaments (SLs) of horses after denervating these ligaments and to investigate the effect chronic inflammation might have on these changes. Methods: 10 horses. Methods: The SL of 1 randomly selected pelvic limb of each of 5 horses was injected with collagenase to induce desmitis, and 42 days later, the proximal aspect of both pelvic SLs were denervated. The SLs were harvested 120 days after being denervated, and the morphological and histological characteristics of each collagenase-injected, denervated SL were compared with those of the ...
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...
Pluim M, Heier A, Plomp S, Boshuizen B, Gröne A, van Weeren R, Vanderperren K, Martens A, Dewulf J, Chantziaras I, Koene M, Luciani A, Oosterlinck M....High-power laser therapy gained popularity recently as a regenerative treatment for tendinitis and desmitis in the horse. However, studies evaluating the effects of laser therapy on tissue repair at the histological level in large mammals are lacking. Objective: To evaluate the effects of high-power laser therapy on suspensory desmitis healing, using a model of suspensory ligament branch injury. Methods: In vivo experiments. Methods: Standardised lesions were surgically induced in all four lateral suspensory branches of 12 healthy Warmblood horses. Laser therapy (class 4, 15W) was applied dail...
Bergmann W, de Lest CV, Plomp S, Vernooij JCM, Wijnberg ID, Back W, Gröne A, Delany MW, Caliskan N, Tryfonidou MA, Grinwis GCM.Gross morphology of healthy and degenerated intervertebral discs (IVDs) is largely similar in horses as in dogs and humans. For further comparison, the biochemical composition and the histological and biochemical changes with age and degeneration were analyzed in 41 warmblood horses. From 33 horses, 139 discs and 2 fetal vertebral columns were evaluated and scored histologically. From 13 horses, 73 IVDs were assessed for hydration, DNA, glycosaminoglycans, total collagen, hydroxyl-lysyl-pyridinoline, hydroxylysine, and advanced glycation end-product (AGE) content. From 7 horses, 20 discs were ...
Fortin-Trahan R, Lemirre T, Santschi EM, Janes JG, Richard H, Fogarty U, Beauchamp G, Girard CA, Laverty S.There is a knowledge gap about how equine MFC subchondral radiolucencies (SR) arise and evolve. Osteoclasts are believed to have a role but have not been studied in situ. Objective: To measure and compare osteoclast density and the percentage of chondroclasts in healthy and MFC SR specimens from juvenile Thoroughbreds. Methods: Cadaveric study. Methods: Medial femoral condyles (MFC) from a tissue bank of equine stifles were studied. Inclusion criteria were MFCs (≤8 months old) with a computed tomography SR lesion and histological focal failure of endochondral ossification (L group). Contral...
Boss CK, Gibson DJ, Schultz G, Whitley RD, Hernandez JA, Abbott JR, Plummer CE.To investigate the therapeutic effects of topical equine amniotic membrane (eAM) suspension following corneal wounding in a controlled experimental setting. Methods: Equine amniotic membrane was collected, gamma irradiated, homogenized for topical suspension preparation, and cryopreserved. Corneoscleral rims harvested from fresh rabbit globes were wounded via keratectomy and were maintained in an air-liquid interface ex vivo corneal culture model. Treatment groups included topical gamma irradiated eAM suspension (n = 20) and a control group (n = 20). Re-epithelialization of the wound was a...
Mund SJK, MacPhee DJ, Campbell J, Honaramooz A, Wobeser B, Barber SM.Limb wounds are common in horses and often develop complications. Intravenous multipotent mesenchymal stromal cell (MSC) therapy is promising but has risks associated with intravenous administration and unknown potential to improve cutaneous wound healing. The objectives were to determine the clinical safety of administering large numbers of allogeneic cord blood-derived MSCs intravenously, and if therapy causes clinically adverse reactions, accelerates wound closure, improves histologic healing, and alters mRNA expression of common wound cytokines. Wounds were created on the metacarpus of 12 ...
Montgomery JB, Klein M, Boire JR, Beck C, Häusermann D, Maksimenko A, Hall CJ.Laminitis is an extremely painful and debilitating condition of horses that can affect their athletic ability and even quality of life. The current gold standard for assessment of laminar tissue is histology, which is the only modality that enables detailed visualization of the lamina. Histology requires dissection of the hoof and therefore can only represent one specific time point. The superior spatial and contrast resolution of synchrotron computed tomography (sCT), when compared with readily available imaging modalities, such as radiographs and conventional CT, provides an opportunity for ...
Serafini R, Varner DD, Love CC.Flow cytometry procedures can be used for evaluation of both spermatogenic efficiency and diagnose disorders of stallion spermatogenesis. Aims of this study were to compare two testicular sample acquisition techniques (needle aspirate-N and tissue wedge-T) and results when using flow cytometry and histology procedures. Testicular cell types were stained with acridine orange, and nine regions (R2 to R10) were identified and enumerated following acquisition by either N or T. Testes were also grouped and analyzed by size and sexual maturity (Small [immature] compared with Large [mature]) and used...
Brum MC, Anjos BL, Nogueira CE, Amaral LA, Weiblen R, Flores EF.An outbreak of severe cutaneous disease associated with an orthopoxvirus in horses in southern Brazil is described. Fourteen Crioulo mares and foals from a husbandry farm developed papules, and vesicles progressing to proliferative and exudative lesions on the muzzle, external nares, and external and internal lips. The vesicles eroded, and the proliferative lesions eventually bled and progressed to moist crusts and scars. The clinical signs lasted approximately 6-12 days, after which the animals progressively recovered. Direct electron microscopy of skin biopsies revealed brick-shaped, 250-300...
Lee CM, Kisiday JD, McIlwraith CW, Grodzinsky AJ, Frisbie DD.It is well documented that osteoarthritis (OA) can develop following traumatic joint injury and is the leading cause of lameness and subsequent wastage of equine athletes. Although much research of injury induced OA has focused on cartilage, OA is a disease that affects the whole joint organ. Methods: In this study, we investigated the impact of synovial cells on the progression of an OA phenotype in injured articular cartilage. Injured and control cartilage were cultured in the presence of synoviocytes extracted from normal equine synovium. Synoviocytes and cartilage were evaluated for catabo...
Gunn HM.Histochemical profiles of individual muscle fibres were established using myosin adenosine triphosphatase (myosin ATPase), succinate dehydrogenase (SDHase), and glycogen phosphorylase (GPase) reactions in three muscles (semitendinosus, diaphragm, and pectoralis transversus) of the horse and dog. The major histochemical difference between fibres lies in their myosin ATPase activity; fibres can be subdivided into those with a high and those with a low activity. In horse muscle, all fibres have a high activity of GPase. In the diaphragm and pectoralis transversus, all fibres have a high SDHase ac...
Cadby JA, David F, van de Lest C, Bosch G, van Weeren PR, Snedeker JG, van Schie HT.Injuries in energy-storing tendons are common in both horses and man. The high prevalence of reinjury and the relatively poor prognosis for returning to preinjury performance levels warrant further research, for which well characterised models would be very helpful. Objective: Given the clinical similarities in tendinopathy of energy-storing tendons, we hypothesised that a recently developed experimental model of equine tendon injury would display many of the characteristics of clinical tendinopathy and could therefore be of use for both species, thus providing comparative insight to the human...
Foland JW, McIlwraith CW, Trotter GW, Powers BE, Lamar CH.Osteochondral fragments were created arthroscopically on the distal aspect of both radial carpal bones in 12 horses. On day 14 after surgery, one middle carpal joint of each horse was injected with 2.5 mL Betavet Soluspan (3.9 mg betamethasone sodium phosphate and 12 mg betamethasone acetate per milliliter) and the contralateral joint was injected with 2.5 mL saline as a control. Intra-articular treatments were repeated on day 35. On day 17, six horses began exercising 5 days per week on a high-speed treadmill. The other six horses were kept in box stalls throughout the study as nonexercised c...
Natali AN, Carniel EL, Frigo A, Pavan PG, Todros S, Pachera P, Fontanella CG, Rubini A, Cavicchioli L, Avital Y, De Benedictis GM.What is the central question of this study? Prostheses for treatment of urinary incontinence elicit complications associated with an inadequate mechanical action. This investigation aimed to define a procedure addressed to urethral mechanical characterization. Experimental tests are the basis for constitutive formulation, with a view to numerical modelling for investigation of the interaction between the tissues and a prosthesis. What is the main finding and its importance? Horse urethra, selected for its histomorphometric similarity to human urethra, was characterized by integrated histologic...
Liuti T, Smith S, Dixon PM.Equine maxillary cheek teeth apical infections are a significant disorder because of frequent spread of infection to the supporting bones. The accuracy of computed tomographic imaging (CT) of this disorder has not been fully assessed. Objective: To compare the radiographic and CT findings in horses diagnosed with maxillary cheek teeth apical infections with pathological findings in the extracted teeth to assess the accuracy of these imaging techniques. Methods: Observational clinical study. Methods: Thirty-two maxillary cheek teeth (in 29 horses) diagnosed with apical infections by clinical, r...
Nyaoke AC, Navarro MA, Beingesser J, Uzal FA.A 14-y-old bay Quarter Horse gelding was presented with progressive neurologic signs, elevated rectal temperature, and icterus for 3 d prior to death. Postmortem examination revealed icterus, large amounts of serosanguineous fluid in the abdominal cavity, widespread petechiae and ecchymoses in several organs, and a large, pale, and well-demarcated focus of necrosis in the liver. Histologically, there was coagulative necrosis surrounded by a rim of inflammatory cells and large numbers of gram-positive rods, which were identified as Clostridium novyi by immunohistochemistry. Liver samples tested...
Korthagen NM, Brommer H, Hermsen G, Plomp SGM, Melsom G, Coeleveld K, Mastbergen SC, Weinans H, van Buul W, van Weeren PR.Cartilage repair remains a major challenge and treatment of (osteo)chondral defects generally results in poor quality fibrous repair tissue. Our approach aims to address some of the major biomechanical issues encountered in scaffold-based cartilage repair, such as insufficient stiffness of the scaffolds, step formation at the interface with the native tissue and inadequate integration with the original tissue. Two osteochondral defects were created on the medial femoral trochlear ridge in each stifle of six Shetland ponies. The defects were filled with a bi-layered implant consisting of a poly...
Head KW, Dixon PM.The normal gross and histological anatomy of the equine nasal and paranasal sinuses are reviewed and the relationships between the local anatomy, the occurrence of different tumour types, and of tumour spread are examined. The histological classification of the more common equine sinonasal tumours and tumour-like lesions are discussed. Clinical and pathological descriptions of 50 more recently recorded such tumours are separately tabulated. The literature shows that equine sinonasal tumours, both endemic and sporadic, are relatively uncommon in horses, with non-neoplastic growths such as maxil...
Shinwari MW, Annand EJ, Driver L, Warrilow D, Harrower B, Allcock RJ, Pukallus D, Harper J, Bingham J, Kung N, Diallo IS.In May 2013, the first cases of Australian bat lyssavirus infections in domestic animals were identified in Australia. Two horses (filly-H1 and gelding-H2) were infected with the Yellow-bellied sheathtail bat (YBST) variant of Australian bat lyssavirus (ABLV). The horses presented with neurological signs, pyrexia and progressing ataxia. Intra-cytoplasmic inclusion bodies (Negri bodies) were detected in some Purkinje neurons in haematoxylin and eosin (H&E) stained sections from the brain of one of the two infected horses (H2) by histological examination. A morphological diagnosis of sub-acute m...
Bodaan CJ, Wise LM, Wakelin KA, Stuart GS, Real NC, Mercer AA, Riley CB, Theoret C.Healing is delayed in limb wounds relative to body wounds of horses, partly because of sustained inflammation and inefficient angiogenesis. In laboratory animals, proteins derived from orf virus modulate these processes and enhance healing. We aimed to compare immune cell trafficking and the inflammatory, vascular, and epidermal responses in body and limb wounds of horses and then to investigate the impact of orf virus interleukin-10 and vascular endothelial growth factor-E on these processes. Standardized excisional wounds were created on the body and forelimb of horses and their progression ...
Hibi H, Hatama S, Obata A, Shibahara T, Kadota K.A case of laryngeal squamous cell carcinoma (SCC) and squamous papilloma in a 19-year-old Thoroughbred stallion is described. The animal exhibited severe wheezing caused by laryngopharyngeal stenosis. Histological examination identified laryngeal, laryngotracheal, and guttural pouch tumor masses consisting of areas of SCC. In the epiglottic lesion, the overlying epithelium was replaced by papilloma cells, and superficial cells frequently had nuclear inclusion bodies that expressed oncoprotein E6, which is characteristic of high risk human papillomaviruses. The papillomatous epithelium was cont...
Watkins JP, Auer JA, Gay S, Morgan SJ.Full-thickness defects were surgically created in the superficial digital flexor tendons of the front limbs of 20 horses. Tissues formed within the defect were evaluated histologically, and the collagen composition of the tissue was determined by immunofluorescence. Transformation occurred from loose fibrillar areas of types I and III collagen and pericellular types IV and V collagen to dense bundles of type I collagen fibers. Loose fibrillar areas of types I and III collagen were present after 24 weeks. Histologically, in horses killed after 2 weeks, the tissue within the defect was a randoml...
Colombino E, Raspa F, Perotti M, Bergero D, Vervuert I, Valle E, Capucchio MT.The conventional feeding management of horses is still characterized by high starch and low fibre diets, which can negatively affect horse's gastrointestinal health. Thus, the aim of this study was to compare the effects of a high-starch (HS) vs. a high-fibre (HF) diet on gut health in horses. A total of 19 Bardigiano horses destined for slaughter and aged 14.3 ± 0.7 months were randomly allotted to two dietary groups: HS (5 fillies and 4 colts,) and HF group (7 fillies and 3 colts). They received the same first-cut meadow hay but different complementary feeds for 72 days: HS group was ...
Vinardell T, Dejica V, Poole AR, Mort JS, Richard H, Laverty S.The mechanisms leading to degeneration of articular cartilage in osteoarthritis (OA) are complex and not yet fully understood. Cathepsin K (CK) is a cysteine protease which can also cleave the triple helix of type II collagen. This exposes a neoepitope that can now be identified by specific antibodies. The aim of this study was to obtain evidence suggesting a role for CK in naturally occurring equine OA in both lesional and peri-lesional regions. Methods: Articular cartilages (n=12 horses; 5 healthy, 7 OA) were harvested from animals postmortem. A gross macroscopic examination, histologic (Saf...
Fortier LA, Nixon AJ, Lust G.To assess the effects of supraphysiologic concentrations of insulin-like growth factor-1 (IGF-1) on morphologic and phenotypic responses of chondrocytes. Methods: Articular cartilage obtained from 2 young horses. Methods: Chondrocytes were suspended in fibrin cultures and supplemented with 25, 12.5, or 0 mg of IGF-1/ml of fibrin. Chondrocyte morphology and phenotypic expression were assessed histologically, using H&E and Alcian blue stains, immunoreaction to collagen type I and II, and in situ hybridization. Proteoglycan content, synthesis, and monomer size were analyzed. The DNA content w...
Wise LM, Bodaan CJ, Stuart GS, Real NC, Lateef Z, Mercer AA, Riley CB, Theoret CL.Bandaging of limb wounds in horses leads to formation of exuberant granulation tissue (EGT) that retards healing due to protracted inflammation, aberrant vascularisation and delayed epithelialisation. EGT is not observed if wounds are left undressed or when wounds are on the body. A previous study showed that short-term administration of proteins derived from orf virus dampened inflammation and promoted epithelialisation of open wounds in horses. Here, we investigated the impact of orf virus interleukin-10 and vascular endothelial growth factor-E on the development and resolution of EGT. Excis...
Dugan SJ, Roberts SM, Curtis CR, Severin GA.Between January 1978 and December 1988, 147 horses with ocular/adnexal squamous cell carcinoma (SCC) were admitted to the Colorado State University Veterinary Teaching Hospital (CSU-VTH). Diagnosis was confirmed by histologic examination of appropriate tissue specimens. Medical records and communication with owners, referring veterinarians, or both provided information regarding initial examination, treatment at the CSU-VTH, and final outcome. At initial examination, 123 (83.7%) horses had unilateral involvement and 24 (16.3%) horses had bilateral involvement. The nictitating membrane, nasal c...
Miller RE, Grodzinsky AJ, Barrett MF, Hung HH, Frank EH, Werpy NM, McIlwraith CW, Frisbie DD.The goal of this study was to test the ability of an injectable self-assembling peptide (KLD) hydrogel, with or without microfracture, to augment articular cartilage defect repair in an equine cartilage defect model involving strenuous exercise. Methods: Defects 15 mm in diameter were created on the medial trochlear ridge and debrided down to the subchondral bone. Four treatment groups (n = 8 each) were tested: no treatment (empty defect), only defect filling with KLD, only microfracture, and microfracture followed by filling with KLD. Horses were given strenuous exercise throughout the one-ye...
Petter-Puchner AH, Froetscher W, Krametter-Froetscher R, Lorinson D, Redl H, van Griensven M.While fibrin sealant (FS) and equine collagen (EC) have been used as scaffold materials in experimental spinal cord injury (SCI), questions concerning neurocompatibility still remain. In this study, we assessed potential adverse effects, as well as functional and histological impact of FS and EC in subtotal hemisection of the thoracic spinal cord (SC) in rats. Methods: 124 male rats were randomly assigned to four main groups (n=31): Sham (SH), Lesion only (L), fibrin sealant (GFS) and equine collagen group (GEC). SH animals received laminectomy only; all other animals underwent subtotal latera...
Patnaik AK.In a retrospective study, granular cell tumors in six dogs (Nos. 1-6), three cats (Nos. 1-3), one horse (No. 1), and one cockatiel (Nymphicus hollandicus) (No. 1) and a meningioma with a granular cell component in one dog (No. 7) were examined histologically and immunohistochemically. These tumors were identified by histologic examination of surgical biopsy specimens, except in the horse, in which the tumor was an incidental finding at necropsy. These diagnoses were initially made by more than one pathologist. Five of the six granular cell tumors in the dogs were in the oral cavity; one of the...
Brits D, Steyn M, L'Abbé EN.Histology is used to describe post-mortem bone alterations, trauma, pathology and age estimation and to separate human and non-human bones. Many scholars are however not familiar with the intricate and variable microstructure of bone, and due to the complex nature of some classification systems, bone histomorphology is often incorrectly described or identified. Little information is available on the histomorphology of non-human bones found in southern Africa, and therefore, the aim of this study was to describe the histomorphology of non-human species commonly found in southern Africa, namely,...
Rho JY, Currey JD, Zioupos P, Pharr GM.The equine radius is a useful subject for examining the adaptation of bone histology to loading because in life the anterior cortex is loaded almost entirely in tension, the posterior cortex in compression. The histology of the two cortices is correspondingly different, the osteones and the interstitial lamellae in the posterior cortex having a more transversely oriented fibre arrangement than those in the anterior cortex. Presumably as a result of this histological difference, the posterior cortex is stronger in compression than the anterior cortex; the anterior cortex is stronger in tension ...
van Heerden J, Els HJ, Raubenheimer EJ, Williams JH.Besnoitiosis was confirmed in a pony which presented with inspiratory dyspnoea, scleroderma and ventral oedema. Numerous cysts were visible in the sclerae. Histological examination of the skin confirmed the presence of numerous cysts. The parasite could not be transmitted by subcutaneous injection of homogenised skin from the infected horse to rabbits and a horse. Ultrastructural morphology of the crescent-shaped bradyzoites was not compatable with Besnoitia besnoiti or B. jellisoni and it is proposed that the infection was caused by B. bennetti.
Murray RC, Zhu CF, Goodship AE, Lakhani KH, Agrawal CM, Athanasiou KA.Dorsal carpal osteochondral injury is a major cause of reduced performance in horses undergoing high-intensity training. It was hypothesised that the mechanical behaviour and histology of cartilage are influenced by the intensity of exercise and by location within a joint. Relationships between histology and mechanical behaviour were identified in 2-year-old horses undergoing 19 weeks of high-intensity treadmill training or low-intensity exercise and then compared between groups. Dorsal and palmar test sites were identified on radial, intermediate, and third carpal articular surfaces after eut...
Ploeg M, Saey V, Delesalle C, Gröne A, Ducatelle R, de Bruijn M, Back W, van Weeren PR, van Loon G, Chiers K.Aortic rupture in horses is a rare condition. Although it is relatively common in the Friesian breed, only limited histopathologic information is available. Twenty Friesian horses (1-10 years old) were diagnosed with aortic rupture by postmortem examination. Ruptured aortic walls were analyzed with histology and immunohistochemistry. Based on the histologic and immunohistochemical findings, these cases were divided into 3 groups: acute (n = 4, 20%), subacute (n = 8, 40%), and chronic (n = 8, 40%). Features common to samples from horses in all groups included accumulation of mucoid material; di...
Menarim BC, Gillis KH, Oliver A, Mason C, Ngo Y, Werre SR, Barrett SH, Luo X, Byron CR, Dahlgren LA.Osteoarthritis (OA) is characterized by macrophage-driven synovitis. Macrophages promote synovial health but become inflammatory when their regulatory functions are overwhelmed. Bone marrow mononuclear cells (BMNCs) are a rich source of macrophage progenitors used for treating chronic inflammation and produce essential molecules for cartilage metabolism. This study investigated the response to autologous BMNC injection in normal and inflamed joints. Synovitis was induced in both radiocarpal joints of 6 horses. After 8 h, 1 inflamed radiocarpal and 1 normal tarsocrural joint received BMNC injec...
Wenzlow N, Neal D, Stern AW, Prakoso D, Liu JJ, Delcambre GH, Beachboard S, Long MT.Estimation of the postmortem interval (PMI) is a poorly studied field in veterinary pathology. The development of field-applicable methods is needed given that animal cruelty investigations are increasing continually. We evaluated various histologic criteria in equine brain, liver, and muscle tissue to aid the estimation of PMI in horses, which is central to forensic investigations of suspicious death. After death, autolysis proceeds predictably, depending on environmental conditions. Currently, no field-applied methods exist that accurately estimate the PMI using histology in animals or human...
