Fibrosis in horses refers to the formation of excess fibrous connective tissue as a reparative or reactive process following injury or inflammation. This condition can affect various organs and tissues, including the lungs, liver, and skin, leading to impaired function and structural changes. Fibrosis is characterized by the excessive deposition of extracellular matrix components, such as collagen, which can result in tissue stiffness and scarring. In equine medicine, fibrosis can be associated with chronic conditions such as equine asthma or hepatic disease. This page compiles peer-reviewed research studies and scholarly articles that investigate the mechanisms, diagnosis, and management of fibrosis in horses, offering insights into its impact on equine health and potential therapeutic approaches.
Franke J, Abs V, Zizzadoro C, Abraham G.Airway fibroblasts have become a critical addition to all facets of structural lung tissue changes such as in human asthma and chronic obstructive pulmonary disease, but little is known about their role in the equine recurrent airway obstruction, a disease that resembles to the human asthma. Since the equine bronchial fibroblasts (EBF) have not been isolated and characterized yet, the use of defined medium was investigated. Results: Primary EBF were cultured on non-collagen coated flasks without serum or in the presence of fetal bovine serum (FBS) or horse serum (HS) or in serum depleted mediu...
Warnock JJ, Fox DB, Stoker AM, Beatty M, Cockrell M, Janicek JC, Cook JL.Introduction. Tissue engineering is a new methodology for addressing meniscal injury or loss. Synovium may be an ideal source of cells for in vitro meniscal fibrocartilage formation, however, favorable in vitro culture conditions for synovium must be established in order to achieve this goal. The objective of this study was to determine cellularity, cell distribution, and extracellular matrix (ECM) formation of equine fibroblast-like synoviocytes (FLS) cultured on synthetic scaffolds, for potential application in synovium-based meniscal tissue engineering. Scaffolds included open-cell poly-L-l...
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...
Aristizabal FA, Lopes MA, Silva A, Avanza MF, Nieto JE.To evaluate the effect of onlay mesenteric flaps (MFs) with end-to-end jejunojejunostomy on stomal diameter, length of jejunum with reduced stomal diameter, abdominal adhesion formation, and healing. Methods: Experimental study. Methods: Healthy adult horses (n = 6). Methods: Two hand sewn end-to-end jejunal anastomoses using a 1 layer simple continuous serosubmucosal suture pattern were performed in each horse ∼ 2 and 5 m oral to the ileocecal fold. Using a random design for selection anastomosis location (oral or aboral), 1 anastomosis was covered with 2 adjacent onlay MFs secured with int...
Dunowska M, Hardcastle MR, Tonkin FB.A 10-year-old polo mare presented with a history of weight loss, poor condition and inappetance. Results: The mare was tachycardic, tachypnoeic and febrile. Harsh lung sounds were auscultated over all lung fields. The mare initially responded to treatment with antibiotics, anti-inflammatory drugs and bronchodilators. Throughout the course of treatment, there was a variable lymphocytosis, monocytosis and fluctuation in concentrations of fibrinogen. The mare also developed a mild anaemia, most likely due to chronic disease. Despite treatment, the mare's condition deteriorated over the following ...
Williams KJ.Progressive lung fibrosis in humans, typified by idiopathic pulmonary fibrosis (IPF), is a serious cause of morbidity and mortality in people. Similar diseases have been described in dogs, cats, and horses. The cause and pathogenesis of such diseases in all species is poorly understood. There is growing evidence in human medicine that IPF is a manifestation of abnormal wound repair in response to epithelial injury. Because viruses can contribute to epithelial injury, there is increasing interest in a possible role of viruses, particularly gammaherpesviruses, in the pathogenesis of pulmonary fi...
Dakin SG, Dudhia J, Smith RK.Injuries to the superficial digital flexor tendon (SDFT) are an important cause of morbidity and mortality in equine athletes, but the healing response is poorly understood. One important drive for the healing of connective tissues is the inflammatory cascade, but the role of inflammation in tendinopathy has been contentious in the literature. This article reviews the processes involved in the healing of tendon injuries in natural disease and experimental models. The importance of inflammatory processes known to be active in tendon disease is discussed with particular focus on recent findings ...
Barakzai SZ, Dixon PM, Hawkes CS, Cox A, Barnett TP.To describe a complication observed endoscopically in horses after prosthetic laryngoplasty (LP). Methods: Case series. Methods: Horses (n = 5) that had previous LP. Methods: Four horses had endoscopic examination as part of a larger prospective study and had saliva emanating from their upper esophageal opening. One other horse was referred with clinical signs of severe upper esophageal obstruction 2 months after LP. Results: Four horses were observed to have saliva emanating from their upper esophageal opening during endoscopic examination 21-58 months after LP. Esophageal reflux was note...
Boone LH, Epstein K, Cremer J, Rogers A, Foutz T, Quandt J, Howerth E, Mueller PO.To compare tensile strength, failure location, and histologic features after acute repeat celiotomy through a ventral median (RVM) or a right ventral paramedian (RVP) celiotomy in horses. Methods: Ex vivo experimental study. Methods: Adult horses (N = 18). Methods: Twelve adult horses had original ventral median (OVM) celiotomy. Repeat celiotomy was performed 72 hours postoperatively through the original ventral median (RVM, N = 6) or a RVP (N = 6) celiotomy. Celiotomies were scored daily for edema, drainage, and dehiscence. Fourteen days after repeat celiotomy, horses were eutha...
Hawkins JF, Couetil L, Miller MA.The objective was to evaluate CO2 laser debridement of the cricoarytenoid joint (CAJ) combined with prosthetic laryngoplasty to prevent post-operative loss of arytenoid abduction in seven horses. Horses were assigned to either laser debridement of the left CAJ and laryngoplasty (laser treated, n=5) or control laryngoplasty (sham, n=2), and were evaluated with endoscopic examinations and measurement of right to left angle quotients (RLQ) to assess maintenance of arytenoid abduction. The animals were euthanased at intervals after surgery and larynges were harvested for post-mortem testing, inclu...
Potocki L, Lewinska A, Klukowska-Rötzler J, Bielak-Zmijewska A, Grabowska W, Rzeszutek I, Kaminska P, Roga E, Bugno-Poniewierska M, Slota E....Bovine papillomavirus 1 (BPV-1) is a well recognized etiopathogenetic factor in a cancer-like state in horses, namely equine sarcoid disease. Nevertheless, little is known about BPV-1-mediated cell transforming effects. It was shown that BPV-1 triggers genomic instability through DNA hypomethylation and oxidative stress. In the present study, we further characterized BPV-1-positive fibroblasts derived from sarcoid tumors. The focus was on cancer-like features of sarcoid-derived fibroblasts, including cell cycle perturbation, comprehensive DNA damage analysis, end-replication problem, energy me...
Williams KJ, Robinson NE, Lim A, Brandenberger C, Maes R, Behan A, Bolin SR.Gammaherpesviruses (γHV) are implicated in the pathogenesis of pulmonary fibrosis in humans and murine models of lung fibrosis, however there is little direct experimental evidence that such viruses induce lung fibrosis in the natural host. The equine γHV EHV 5 is associated with equine multinodular pulmonary fibrosis (EMPF), a progressive fibrosing lung disease in its natural host, the horse. Experimental reproduction of EMPF has not been attempted to date. We hypothesized that inoculation of EHV 5 isolated from cases of EMPF into the lungs of clinically normal horses would induce lung fibr...
Theoret CL, Olutoye OO, Parnell LK, Hicks J.To compare histopathologic features of a fibroproliferative disorder in horses (exuberant granulation tissue-EGT) and people (keloid). Methods: Archival tissue samples of EGT (n = 8) and keloid (12). Methods: After automated hematoxylin and eosin, histochemical (Gomori trichrome, Verhoeff-van Gieson elastin) and immunohistochemical (vimentin, α-smooth muscle actin, CD34, CD68, CD117) stainings, tissue sections were evaluated using a semi-quantitative grading scale for presence or absence of ulceration, keloidal collagen, myofibroblasts, and elastic fibers as well as degree of inflammation, fi...
Schwarz B, Klang A, Bezdekova B, Sárdi S, Kutasi O, Hoven R.Equine multinodular pulmonary fibrosis (EMPF), a progressive fibrosing interstitial lung disease has been associated with gammaherpesviruses. This case series describes five horses with EMPF. Three of the horses (two in Hungary, one in the Czech Republic) were diagnosed with EMPF ante mortem. They presented with typical clinical signs of EMPF including dyspnoea and weight loss. Arterial blood gas analysis revealed hypoxaemia. Blood work showed signs of inflammation like neutrophilia and hyperfibrinogenaemia. An endoscopic examination of the respiratory tract including cytology and culture of t...
Altamura G, Corteggio A, Nasir L, Yuan ZQ, Roperto F, Borzacchiello G.Equine sarcoids are skin tumours of fibroblastic origin affecting equids worldwide. Bovine papillomavirus type-1 (BPV-1) and, less commonly, type-2 are recognized as etiological factors of sarcoids. The transforming activity of BPV is related to the functions of its major oncoprotein E5 which binds to the platelet-derived growth factor β receptor (PDGFβR) causing its phosphorylation and activation. In this study, we demonstrate, by coimmunoprecipitation and immunoblotting, that in equine sarcoid derived cell lines PDGFβR is phosphorylated and binds downstream molecules related to Ras-mitoge...
Nemoto M, Kizaki K, Yamamoto Y, Oonuma T, Hashizume K.In vitro cell studies might be a useful tool for studying tendon pathology, but no suitable in vitro models exist for tendon disorders. The purpose of this study was to confirm whether cell scratch culture using tendon-derived fibroblasts can provide a suitable in vitro tendon disorder model. Extracellular matrix components were examined immunohistochemically in tendon tissue, and then their related gene expression levels were analyzed by conventional reverse transcription polymerase chain reaction (RT-PCR) and/or quantitative real-time RT-PCR in tissues and cells. Collagen type I (Col I), col...
Spelta CW, Axon JE, Begg A, Diallo IS, Carrick JB, Russell CM, Collins NM.Equine multinodular pulmonary fibrosis (EMPF) is a recently described form of interstitial pneumonia associated with the presence of equine herpesvirus type 5 (EHV-5). Since 2007, several case reports from America, Europe and the United Kingdom have further characterised the clinical presentation and laboratory findings of this disease. Methods: Three Thoroughbred broodmares were diagnosed with EMPF. Diagnosis was based on lung histopathology and positive identification of EHV-5 using PCR DNA amplification. There was multiple organ involvement in all three cases, including identification of EH...
Donnelly KS, Giuliano EA, Sharma A, Tandon A, Rodier JT, Mohan RR.To explore (i) the potential of polyethylenimine (PEI) nanoparticles as a vector for delivering genes into equine corneal fibroblasts (ECFs) using green fluorescent protein (GFP) marker gene, (ii) whether PEI nanoparticle-mediated decorin (DCN) gene therapy could be used to inhibit fibrosis in the equine cornea using an in vitro model. Methods: Polyethylenimine-DNA nanoparticles were prepared at nitrogen-to-phosphate (N-P) ratio of 15 by mixing 22 kDa linear PEI and a plasmid encoding either GFP or DCN. ECFs were generated from donor corneas as previously described. Initially, GFP was introduc...
Pessoa CR, Pessoa AF, Maia LA, Medeiros RM, Colegate SM, Barros SS, Soares MP, Borges AS, Riet-Correa F.The effects and susceptibility of donkeys to Crotalaria juncea and Crotalaria retusa poisoning were determined at high and low doses. Seeds of C. juncea containing 0.074% of dehydropyrrolizidine alkaloids (DHPAs) (isohemijunceines 0.05%, trichodesmine 0.016%, and junceine 0.008%) were administered to three donkeys at 0.3, 0.6 and 1 g/kg body weight (g/kg) daily for 365 days. No clinical signs were observed and, on liver and lung biopsies, the only lesion was a mild liver megalocytosis in the donkeys ingesting 0.6 and 1 g/kg/day. Two other donkeys that received daily doses of 3 and 5 g seed/...
Neuhauser S, Handler J.The aims of this study were to compare two different methods of quantifying the colour of the luminal surface of the equine endometrium and to relate the results to histopathological evidence of inflammation and fibrosis. The mucosal surfaces of 17 equine uteri obtained from an abattoir were assessed using a spectrophotometer and by computer-assisted analysis of photographs. Values were converted into L(*)a(*)b(*) colour space. Although there was significant correlation between the two methods of quantification, variations in 'brightness', 'red' and 'yellow' values were noted. Within a given u...
Cushing TL.A 4-year-old crossbred Quarterhorse mare was submitted to the Clemson Veterinary Diagnostic Center for necropsy examination with a chronic history of inappetence, weight loss and lethargy. Prior to death the horse had developed mild diarrhoea and began showing evidence of colic. Necropsy examination revealed a markedly enlarged heart due predominantly to marked dilation of the right atrium, tortuous congested mesenteric blood vessels, marked ascites, pleural effusion and pulmonary oedema. Further examination of the heart showed the endocardium of the left side of the heart, including the mitra...
Lunardi M, de Alcântara BK, Otonel RA, Rodrigues WB, Alfieri AF, Alfieri AA.Equine sarcoids are locally aggressive fibroblastic neoplasms considered to be the most common skin tumors of horses worldwide. Bovine papillomavirus types 1 and 2 have typically been associated with sarcoids in equids. Investigations aiming to identify papillomavirus strains, aside from bovine papillomaviruses 1 and 2, which might be associated with sarcoid lesions, have been lacking. The aim of this article is to report the identification of a third bovine papillomavirus type, bovine papillomavirus 13, associated with equine sarcoids. Six sarcoid lesions were collected from diverse anatomica...
Giannitti F, Petrov R, Parker J, Booth M, Anderson M.A 9-year-old Thoroughbred gelding presented with a 97-day history of poor performance and intermittent fever. Clinicopathologic changes included increased serum activity of γ-glutamyltransferase and alkaline phosphatase, mild hyperbilirubinemia, and leukocytosis with neutrophilia and lymphopenia. Abdominal ultrasound revealed hepatomegaly with hyperechoic hepatic parenchyma and biliary distention. Pathologic findings included marked hepatomegaly (liver 3.6% of body weight), firm hepatic consistency with a diffuse enhanced reticular pattern, severe portal bridging and sinusoidal fibrosis, oval...
Bird AR, Knowles EJ, Sherlock CE, Pearson GR, Mair TS.Gastric impaction in the horse is poorly described in the veterinary literature. Objective: To review the clinical and pathological features of gastric impaction. Methods: The clinical details of horses presenting with colic over a 7-year period and cases in which gastric impaction was considered to determine the outcome were reviewed. Clinical and clinicopathological data were recorded. Results: Twelve cases of gastric impaction were recorded (1.4% of 857 horses hospitalised for colic). Diagnosis was achieved by ultrasonographic examination, gastroscopy, exploratory celiotomy and/or post mort...
Janicek J, Lopes MA, Wilson DA, Reed S, Keegan KG.Fibrotic myopathy can cause incapacitating gait abnormalities. Transection of the fibrotic mass followed by early post operative exercise is the best treatment for fibrotic myopathy. A laser may be used to transect the fibrotic mass. Assessment of the effectiveness of therapies for fibrotic myopathy has been limited to subjective evaluation. Objective: To objectively assess gait abnormalities associated with fibrotic myopathy before and after laser fibrotomy followed by early post operative exercise. Methods: Kinematic evaluation of horses with fibrotic myopathy walking and trotting on a tread...
Theoret CL, Wilmink JM.Impaired wound healing represents an enormous clinical and financial problem for companion animals and humans alike. Unfortunately, most models used to study healing rely on rodents, which have significant differences in the healing and scarring process and rarely develop complications. In order to better simulate impaired healing, the model should strive to reproduce the natural processes of healing and delayed healing. Wounds on the limbs of horses display similarities to wounds in humans in their epithelialization/contraction ratio, genetic influence as well as dysregulated cytokine profile...
Williams KJ, Robinson NE, Defeijter-Rupp H, Millerick-May M, Stack A, Hauptman J, Derksen FJ.Exercise-induced pulmonary hemorrhage (EIPH), which has been reported in humans and a variety of domestic animals following strenuous exercise, is most often documented in racehorses. Remodeling of pulmonary veins (VR) in equine EIPH was recently described, suggesting that it contributes to the pathogenesis of the disease. The cause of VR is unknown. We tested the hypothesis that the development of VR follows pulmonary blood flow distribution, preferentially occurring in the caudodorsal lung region. Furthermore, we hypothesized that VR underpins development of the other lesions of EIPH patholo...
Reed SA, Johnson SE.Recovery from tendon injury is based on long periods of rest, which results in sub-optimal repair, often replacing tendon with fibrocartilage scar tissue. Recently, the use of stem cells in equine tendon repair has been attempted with variable success. The objective of this work was to determine the expression of scleraxis (scx) and tenascin C (TnC), two markers of tenocytes, in adipose (AdMSC) and umbilical cord blood (UCB) stem cells during culture on various substrata and in response to fibroblast growth factor (FGF) treatment. Equine UCB and AdMSC were cultured on gelatin-coated plasticwar...
Finlay M, Yuan Z, Morgan IM, Campo MS, Nasir L.Bovine papillomavirus type 1 infects not only cattle but also equids and is a causative factor in the pathogenesis of commonly occurring equine sarcoid tumours. Whilst treatment of sarcoids is notoriously difficult, cisplatin has been shown to be one of the most effective treatment strategies for sarcoids. In this study we show that in equine fibroblasts, BPV-1 sensitises cells to cisplatin-induced and UVB-induced apoptosis, a known cofactor for papillomavirus associated disease, however BPV-1 transformed fibroblasts show increased clonogenic survival, which may potentially limit the therapeut...
Södersten F, Hultenby K, Heinegård D, Johnston C, Ekman S.This is a descriptive study of tendon pathology with different structural appearances of repair tissue correlated to immunolocalization of cartilage oligomeric matrix protein (COMP) and type I and III collagens and expression of COMP mRNA. The material consists of nine tendons from seven horses (5-25 years old; mean age of 10 years) with clinical tendinopathy and three normal tendons from horses (3, 3, and 13 years old) euthanized for non-orthopedic reasons. The injured tendons displayed different repair-tissue appearances with organized and disorganized fibroblastic regions as well as areas o...
Dabareiner RM, Schmitz DG, Honnas CM, Carter GK.Injury to the gracilis muscle can cause acute, severe lameness in horses. Two female Quarter Horses that were used for barrel racing sustained gracilis muscle tear injuries. The site of injury was localized by direct infiltration of the area with mepivacaine. The extent of muscle tearing and seroma formation was determined via ultrasonographic evaluation. One horse developed fibrotic myopathy approximately 3 months after the original injury and underwent surgery to transect a palpable fibrous band at the previous injury site. Both horses returned to barrel racing 5 to 6 months after the injury...
Alpoim-Moreira J, Szóstek-Mioduchowska A, Słyszewska M, Rebordão MR, Skarzynski DJ, Ferreira-Dias G.Endometrosis negatively affects endometrial function and fertility in mares, due to excessive deposition of type I (COL1) and type III (COL3) collagens. The pro-fibrotic transforming growth factor (TGF-β1) induces myofibroblast differentiation, characterized by α-smooth muscle actin (α-SMA) expression, and collagen synthesis. In humans, fibrosis has been linked to epigenetic mechanisms. To the best of our knowledge, this has not been described in mare endometrium. Therefore, this study aimed to investigate the in vitro epigenetic regulation in TGF-β1-treated mare endometrial fibroblasts an...
Eggleston RB, Mueller E, Quandt JE, Neuwirth L, Harmon BG, Waguespack WR, Rainbow ME.To compare the outcomes of double-layer inverting anastomosis (DIA), single-layer anastomosis (SLA), and single-layer anastomosis combined with a hyaluronate membrane (SLA+HA-membrane) with respect to stomal diameter, adhesion formation, surgery time, and anastomotic healing in horses. Methods: 18 adult horses. Methods: Midline celiotomy and end-to-end anastomoses were performed. In control horses (n = 6), DIA was performed; in treated horses, SLA was performed (6) or SLA+HA-membrane was performed (6). Horses were euthanatized 21 days after surgery. Abdominal adhesions were evaluated grossly a...
Breider MA, Kiely RG, Edwards JF.A generalized debilitating disease in a horse was believed to be related to hypersensitivity to migrating strongyle larvae. The clinical signs included weight loss, diarrhea, and ulcers on all 4 coronary bands. The mare's condition deteriorated rapidly, so the mare was euthanatized and necropsied. The major histopathologic findings were chronic multifocal eosinophilic pancreatitis, hepatic portal fibrosis, biliary hyperplasia, and chronic ulcerative eosinophilic colitis. This case was similar to previously reported cases of chronic eosinophilic gastroenteritis in horses. Although the etiologic...
Miller RI, Campbell RS.A survey of granulomatous and neoplastic diseases of the skin of horses of tropical north Queensland was carried out during the period 1970-1980. Of 338 horses affected, 46.4% suffered from equine fibrosarcoma (sarcoid), 30.2% from phycomycosis, 7.4% from squamous cell carcinoma, 6.8% from other tumours, 4.7% from cutaneous habronemiasis and 4.4% from exuberant granulation tissue. Most specimens were submitted during the first half of the year after the wet monsoonal season and significantly more diseases originated during the first quarter. There was minor variations with breed, age and sex s...
van Dyk E, Lange AL.Fifty ml of a 0.2% iodine solution were instilled into the uteri of six mares selected for culling. Biopsy specimens were taken for microscopic examination before the commencement of the experiment and at various times over the course of a year after the single instillation. Severe oedema and haemorrhage was present in the lamina propria of all the post-instillation biopsy specimens. The epithelium showed vacuolisation and necrosis, as well as focal areas of epithelial loss. In some cases hyperplasia or metaplasia was seen. Cell infiltration was characterized by the presence of neutrophils, eo...
Potocki L, Lewinska A, Klukowska-Rötzler J, Bielak-Zmijewska A, Grabowska W, Rzeszutek I, Kaminska P, Roga E, Bugno-Poniewierska M, Slota E....Bovine papillomavirus 1 (BPV-1) is a well recognized etiopathogenetic factor in a cancer-like state in horses, namely equine sarcoid disease. Nevertheless, little is known about BPV-1-mediated cell transforming effects. It was shown that BPV-1 triggers genomic instability through DNA hypomethylation and oxidative stress. In the present study, we further characterized BPV-1-positive fibroblasts derived from sarcoid tumors. The focus was on cancer-like features of sarcoid-derived fibroblasts, including cell cycle perturbation, comprehensive DNA damage analysis, end-replication problem, energy me...
Derksen FJ, Williams KJ, Uhal BD, Slocombe RF, de Feijter-Rupp H, Eberhart S, Berney C, Robinson NE.Exercise-induced pulmonary haemorrhage (EIPH) occurs in the majority of horses performing strenuous exercise. Associated pulmonary lesions include alveolar and airway wall fibrosis, which may enhance the severity of EIPH. Further work is required to understand the pulmonary response to blood in the equine airways. Objective: To confirm that a single instillation of autologous blood into horse airways is associated with alveolar wall fibrosis, and to determine if blood in the airways is also associated with peribronchiolar fibrosis. Methods: Paired regions of each lung were inoculated with bloo...
van der Haegen A, Künzle F, Gerber V, Welle M, Robinson NE, Marti E.Recurrent airway obstruction (RAO) is a common condition in stabled horses characterised by small airway inflammation and obstruction following exposure of susceptible horses to mouldy hay and straw. The aim of the present study was to investigate whether lung tissue from horses with RAO contains higher numbers of IgE-protein positive (+) cells and mast cells compared to controls after mouldy hay challenge. Furthermore, mast cell subtypes in lung tissue were investigated. IgE+ cells were detected in most lung tissue samples but no significant differences between RAO-affected and control horses...
Evans TJ, Miller MA, Ganjam VK, Niswender KD, Ellersieck MR, Krause WJ, Youngquist RS.To develop an objective, quantifiable assay for endometrial periglandular fibrosis (EPF) and correlate assay results with histologic and ultrastructural changes in equine endometrial biopsy specimens. Methods: Endometrial biopsy specimens from 70 mares from 3 to 27 years old in estrus. Methods: In a double-blinded study design, endometrial biopsy specimens were graded histologically (modified Kenney classification) for EPF and inflammation. Endometrial periglandular collagen volume fraction (%EPCVF) was determined by light microscopic image analysis of picrosirius red-stained sections. Specime...
Despite being one of the major causes of infertility in mares, the mechanisms responsible for equine endometrosis are still unclear and controversial. In the last few years, many investigations focused on local immune response modulation. Since it is generally accepted that endometrial fibrosis increases with age, we hypothesize that older mares could show altered local immune modulation, initiating a pro-inflammatory and tissue remodeling cascade of events that could lead to endometrosis. The aim of this study, indeed, is to evaluate and describe the local gene expression of genes involved in...
Sullins KE, Stashak TS, Mero KN.In 6 horses, 2 types of ischemic lesions were created in small intestinal segments by selective ligation of vessels and intestinal wall for 1, 2, or 3 hours. After confirming the ischemia by IV injection of sodium fluorescein, the ligatures were released. Five minutes later, the fluorescent patterns were documented photographically. Observed patterns ranged from normal (identical to that observed in unaffected bowel) to a patchy distribution of non-fluorescence (indicating incomplete perfusion). None of the experimental segments was normal when reevaluated 1 month later. The typical appearance...
Niedermaier G, Poth T, Gehlen H.Two warmblood horses with a history of chronic weight loss and inappetence were referred to the Faculty of Veterinary Medicine, Ludwig-Maximilians University of Munich, Germany, for further examination. The clinical signs in horse 1 were fever, tachycardia and tachypnoea, and chronic ulcerative keratopathy of both eyes. Horse 2 had severe oral ulcerations and was coughing during feeding. In both horses, increased bronchovesicular sounds were heard during auscultation of the lungs. Laboratory findings included mild anaemia, lymphopenia and hypoalbuminaemia. Radiographic examination of the thora...
Staszyk C, Gasse H.Fibroblasts and cementoblasts in the periodontal ligament (PDL) of equine cheek teeth were harvested, and monocultures were obtained by means of a "selective detachment" procedure. Cells were characterized by morphological criteria and by immunostaining for vimentin, FVIII, pan-cytokeratin, smooth muscle actin, and pro-collagen. Cementogenic potential of the cells was determined by immunostaining for osteopontin and by histochemical detection of alkaline phosphatase. Equine periodontal fibroblasts (EPF) were spindle-shaped and polygonal. Equine dental cementoblasts (EDC) grew in cobblestone-li...
Dunkel B, Jones SA, Pinilla MJ, Foote AK.Serum bile acid concentrations (SBA) and a histopathological biopsy score [Equine Vet J 35 (2003) 534] are used prognostically in equine hepatic disease. Objective: Histopathologic features and scores, but not SBA, differ between survivors and nonsurvivors and correlate with histopathologic evidence of hepatic inflammation and fibrosis. Methods: Retrospective study. Records (1999-2011) of horses with hepatic disease diagnosed by biopsy and with concurrent measurements of SBA. Methods: Retrospective cohort study. Biopsies were examined for inflammatory cell infiltration including type and distr...
Du Cheyne C, Martens A, De Spiegelaere W.Exuberant granulation tissue (EGT) is a frequently encountered complication during second intention healing in equine distal limb wounds. Although it is still unknown what exactly triggers the formation of this tissue, previous research has revealed a persistent inflammatory response in these wounds. In this preliminary study we examined this inflammatory response in EGT-developing wounds as well as in experimental induced wounds. Immunohistological stainings were performed to detect primary inflammatory immune cells (MAC387 staining) as well as pro-resolution immune cells (CD163 staining). Ou...
Nation PN.Trifolium hybridum (alsike clover) has been implicated as the cause of two diseases of the horse. One of these is photosensitivity, of which alsike clover is only one of a number of presumed causal agents. The other is a fatal syndrome which is known as "alsike clover poisoning" and which is manifest by progressive loss of condition, signs of hepatic failure, and varying degrees of neurological impairment. The underlying lesion of alsike clover poisoning is fibrosis and proliferation of the biliary tree. The experimental evidence implicating alsike clover as the cause of this syndrome comes en...
Brown DL, Anderson M, Cullen JM.Mesenchymal hamartoma of the liver is a rare congenital disorder of biliary tract development. During the necropsy of a late-term equine fetus, a markedly enlarged liver of more than two times normal weight was found. Light microscopic review revealed that the normal hepatic parenchyma had been obliterated, replaced, and expanded by abnormal bile ducts surrounded by abundant, myxoid stroma. The lesion was diagnosed as a mesenchymal hamartoma. Small portions of the liver had bridging septa of fibrosis and proliferations of small-caliber abnormal bile ducts, resembling another congenital biliary...
Walter I, Helmreich M, Handler J, Aurich C.Chronic degenerative disease of the mare's endometrium is characterised by changes in the uterine glands, including cystic dilation, hyperplasia and periglandular fibrosis. Endometrial biopsies were taken from 23 mares with different grades of endometrial degeneration. Solid structures were identified within the lumina of the uterine glands and shown to be calcified by histochemical staining. Most of them were not homogenous but composed of a mixture of mineral and organic substances. Further examinations of these mineralised structures by immunohistochemical methods revealed the presence of t...
Dubuc V, Lepault E, Theoret CL.Wound repair in horse limbs is often complicated by excessive fibroplasia and scarring. Occlusion of the microvessels populating the granulation tissue appears to be involved in the excessive accumulation of extracellular matrix during the repair of limb wounds. This study aimed to determine whether endothelial cell hypertrophy or hyperplasia, or both, contribute to microvascular occlusion and whether the pericyte is involved in this anomaly. We created 5 wounds, each 2.5 x 2.5 cm, on both forelimbs and on the body of 6 horses. One limb was bandaged to stimulate excessive wound fibroplasia. We...
Williams IF, Heaton A, McCullagh KG.The connective tissue composition and organisation of the "equine sarcoid" was compared with that of normal adult equine skin to determine whether the cells which produce their respective connective tissue matrices show similar biosynthetic characteristics. No major qualitative difference could be found between the collagen compositions of skin and sarcoid material, although the organisation into fibres of Type III collagen in the sarcoid was markedly greater than that of skin.
Fukuda T, Kikuchi M, Kurotaki T, Oyamada T, Yoshikawa H, Yoshikawa T.Atrophy of seminiferous tubules and interstitial fibrosis are frequently observed in aged horses. Samples from 8 male Thoroughbreds, age 4-24 years, were subjected to histological, electron microscopical and immunohistochemical examination and statistical analysis. There were statistically significant increases in collagen fibres in the lamina propria of seminiferous tubules and testicular interstitium in 3 horses age 23 and 24 years compared with 5 horses age 4-20 years (P<0.001). Lamina propria surrounding atrophic tubules was thickened by an increase in collagen type IV and elastic fibre...
Martano M, Altamura G, Power K, Liguori P, Restucci B, Borzacchiello G, Maiolino P.It is well known that δ-bovine papillomaviruses (BPV-1, BPV-2 and BPV-13) are one of the major causative agents of equine sarcoids, the most common equine skin tumors. Different viruses, including papillomaviruses, evolved ingenious strategies to modulate autophagy, a complex process involved in degradation and recycling of old and damaged material. Methods: The aim of this study was to evaluate, by immunohistochemistry (IHC) and Western blot (WB) analysis, the expression of the main related autophagy proteins (Beclin 1, protein light chain 3 (LC3) and P62), in 35 BPV1/2 positive equine sarco...
Sysel AM, Pleasant RS, Jacobson JD, Moll HD, Warnick LD, Sponenberg DP, Eyre P.The purpose of this study was to determine the systemic and local effects associated with long-term epidural catheterization and epidural morphine-detomidine administration in horses. Methods: Development of systemic or local effects was assessed by placing caudal epidural catheters in study horses and administering injections through the catheters every 12 hours for 14 days. Methods: Ten horses with epidural catheters that received daily injections; six uncatheterized horses presented for euthanasia. Methods: Horses received either 0.2 mg/kg morphine sulfate and 30 micrograms/kg detomidine hy...
Amaral A, Fernandes C, Szóstek-Mioduchowska A, Rebordão MR, Skarzynski DJ, Ferreira-Dias G.Endometrosis is a reproductive pathology that is responsible for mare infertility. Our recent studies have focused on the involvement of neutrophil extracellular traps enzymes, such as elastase (ELA), in the development of equine endometrosis. Noscapine (NOSC) is an alkaloid derived from poppy opium with anticough, antistroke, anticancer, and antifibrotic properties. The present work investigates the putative inhibitory in vitro effect of NOSC on collagen type I alpha 2 chain () mRNA and COL1 protein relative abundance induced by ELA in endometrial explants of mares in the follicular or mid-lu...
Leishman D, Miller RB, Doig PA.The density of uterine glands, height of surface epithelium, numbers of hemosiderin laden macrophages, inflammatory cells and layers of periglandular fibrosis were evaluated in uterine biopsies from 40 mares. These features were found to be highly variable in normal equine endometrium. Minor pathological changes appeared to be masked by this normal variability. Atrophy of uterine glands was recognized in mares which had been barren for more than three years. No significant differences were found between barren and normal mares in the height of epithelium, number of hemosiderin laden macrophage...
Waitt LH, Cebra CK, Tornquist SJ, Löhr CV.A 22-year-old pinto mixed breed mare was admitted for evaluation of severe colic signs and gastric reflux. Multiple nonpainful, variably sized hard masses were palpated in the subcutis over the thorax, abdomen, and hindquarters of the horse. The mare was diagnosed with sterile peritonitis and had systemically high gamma-glutamyltransferase, amylase, and lipase. Three days into treatment she became febrile with signs of persistent and mild abdominal discomfort; euthanasia was elected. Necropsy revealed peripancreatitis, pancreatic fibrosis, abdominal steatitis and panniculitis. Panniculitis ass...
Franke J, Abraham G.Altered airway cell proliferation plays an important role in the pathogenesis of human bronchial asthma and chronic obstructive pulmonary disease (COPD) as well as the equine recurrent airway obstruction (RAO) with consistent changes, i.e. narrowing the airway wall, explained by proliferation and differentiation of fibroblasts. In permanent cell lines, it has been suggested that β2-adrenoceptor agonists and glucocorticoids regulate cell proliferation via the β2-adrenoceptor pathway; indeed, no study was carried out in fresh isolated primary equine bronchial fibroblasts (EBF). We characterize...
Miragliotta V, Lefebvre-Lavoie J, Lussier JG, Theoret CL.Wounds on horse limbs can develop exuberant granulation tissue which resembles the human keloid. Clues gained from the study of over-scarring in horses might help control fibro-proliferative disorders. Objective: The aim of the present study was to clone full-length equine ANXA2 cDNA then to study spatio-temporal expression of ANXA2 and MMP1 mRNA and protein, potential contributors to remodeling, during repair of body (normal) and limb (fibro-proliferative) wounds in an established horse wound model. Methods: Cloning of ANXA2 was achieved by screening size-selected cDNA libraries. Expression w...
McKane SA, Slocombe RF.Necropsy studies of horses suffering exercise-induced pulmonary haemorrhage (EIPH) have identified mild inflammatory lesions with evidence of alveolar fibrosis and bronchiolitis. These lesions were thought to be the result of viral infections that predisposed the affected regions of the lung to EIPH. We have shown previously that during erythrophagocytosis in the alveolar space, there is a prolonged period of macrophage influx and activation. This present study used morphometric analysis to quantify the effects of macrophage activity during erythrophagocytosis, on the alveolar cell population ...
