Inflammation is a biological response of the horse's body to harmful stimuli, such as pathogens, damaged cells, or irritants. It is a complex process that involves the activation of immune cells, the release of inflammatory mediators, and changes in blood flow. In horses, inflammation can manifest in various forms, affecting different tissues and organs, including the joints, respiratory system, and skin. The inflammatory response is an essential component of the horse's immune system, aiming to eliminate the initial cause of cell injury, clear out damaged cells and tissues, and establish tissue repair. This topic page gathers peer-reviewed research studies and scholarly articles that explore the mechanisms, effects, and management of inflammation in equine health.
Lopez-Navarro G, Trigo-Tavera FJ, Rodriguez-Monterde A, Gutierrez-Ospina G, Arechavaleta-Velasco M, Schumacher J, Schumacher J.Proximal suspensory desmitis (PSD) is a common cause of lameness in the pelvic limb, but could also affect the thoracic limb of competing and non-competing horses. Most horses diagnosed with PSD in a thoracic limb respond to rest followed by controlled exercise, but in a small percentage of affected horses, lameness persists. In one study, four horses chronically lame because of PSD in a thoracic limb became sound after neurectomy of the deep branch of the lateral palmar nerve (DBLPaN), which innervates the proximal aspect of the suspensory ligament (SL; Guasco et al., 2013). Whether neurectom...
Hauck SM, Lepper MF, Hertl M, Sekundo W, Deeg CA.Equine recurrent uveitis is the only spontaneous model for recurrent autoimmune uveitis in humans, where T cells target retinal proteins. Differences between normal and autoaggressive lymphocytes were identified in this study by analyzing peripheral blood derived lymphocytes (PBL) proteomes from the same case with interphotoreceptor retinoid binding protein induced uveitis sampled before (Day 0), during (Day 15), and after uveitic attack (Day 23). Relative protein abundances of PBL were investigated in a quantitative, label-free differential proteome analysis in cells that were kept frozen for...
Bond SL, Timsit E, Workentine M, Alexander T, Léguillette R.The microbial composition of the equine respiratory tract, and differences due to mild equine asthma (also called Inflammatory Airway Disease (IAD)) have not been reported. The primary treatment for control of IAD in horses are corticosteroids. The objectives were to characterize the upper and lower respiratory tract microbiota associated with respiratory health and IAD, and to investigate the effects of dexamethasone on these bacterial communities using high throughput sequencing. Results: The respiratory microbiota of horses was dominated by four major phyla, Proteobacteria (43.85%), Actinob...
Finch SC, Munday JS, Sutherland BL, Vlaming JB, Fletcher LR.AIMS To determine if equine fescue oedema (EFO) induced by grazing Mediterranean-type tall fescue (Lolium arundinaceum) infected with selected endophytes (Epichloë coenophiala) could be prevented by treatment with the corticosteroid, methylprednisolone, and anti-histamine, cetirizine, and to determine concentrations of lolines, specifically N-acetyl norloline (NANL), in grasses grazed by horses that did and did not develop EFO. METHODS Four horses were grazed on AR542-infected Mediterranean tall fescue pasture (from Day 0) for 7 days prior to being subjected to euthanasia. Two of these horses...
Bullone M, Vargas A, Elce Y, Martin JG, Lavoie JP.Asthmatic airways are inflamed and undergo remodelling. Inhaled corticosteroids and long-acting β2-agonist combinations are more effective than inhaled corticosteroid monotherapy in controlling disease exacerbations, but their effect on airway remodelling and inflammation remains ill-defined. This study evaluates the contribution of inhaled fluticasone and salmeterol, alone or combined, to the reversal of bronchial remodelling and inflammation. Severely asthmatic horses (6 horses/group) were treated with fluticasone, salmeterol, fluticasone/salmeterol, or with antigen avoidance for 12 weeks. ...
Christoffersen M, Troedsson M.A transient uterine inflammation post-breeding is a normal physiological reaction in the mare, and it is believed that the inflammatory response is necessary to eliminate bacteria and excess spermatozoa introduced into the uterine lumen. A tight balance between multiple pro- and anti-inflammatory factors is required for resolving the breeding-induced inflammation within 24-36 hr in the reproductively healthy mare, whereas a subpopulation of mares is susceptible to development of a persistent infection that can interfere with fertility. The aetiology of persistent endometritis can be either ba...
Cooper CJ, Keller SM, Arroyo LG, Hewson J, Kenney D, Bienzle D.Leukemia is broadly divided into acute and chronic lymphocytic and myeloid types based on the proportion of blasts, morphology of cells, and expression of specific antigens on neoplastic cells. Classifying leukemia in horses can be challenging if blasts predominate and since few antibodies to identify cell types are available. The objective of this study was to describe in detail the clinical and pathologic features of acute leukemia in horses. Twelve horses ranging from 0.2 to 25.9 years of age were diagnosed with acute leukemia. Six cases were classified as acute lymphocytic leukemia (ALL) b...
Bauquier JR, Tennent-Brown BS, Tudor E, Bailey SR.Polymyxin-B is used to treat equine systemic inflammation. Bacterial toxins other than lipopolysaccharide (LPS) contribute to systemic inflammation but the effects of polymyxin-B on these are poorly defined. Whole blood aliquots from six healthy horses diluted 1:1 with RPMI were incubated for 21 hr with 1 μg/ml of LPS, lipoteichoic acid (LTA) or peptidoglycan (PGN) in the presence of increasing concentrations of polymyxin-B (10-3000 μg/ml). A murine L929 fibroblast bioassay was used to measure TNF-α activity. Polymyxin-B significantly inhibited the effects of all three bacterial toxins. ...
Haspel AD, Giguère S, Hart KA, Berghaus LJ, Davis JL.Nebulisation of the injectable dexamethasone sodium phosphate (DSP) would offer an inexpensive way of delivering a potent corticosteroid directly to the lungs of horses with asthma. However, this approach would be advantageous only if systemic absorption is minimal and if the preservatives present in the formulation do not induce airway inflammation. Objective: To investigate the bioavailability of nebulised DSP and determine whether it induces airway inflammation or hypothalamic-pituitary-adrenal (HPA) axis suppression in healthy adult horses. Methods: Randomised crossover experiment. Methods...
Segabinazzi LG, Friso AM, Correal SB, Crespilho AM, Dell'Aqua JA, Miró J, Papa FO, Alvarenga MA.Persistent mating-induced endometritis (PMIE) results in decreased fertility in horses, thereby causing a significant impact in the horse market. Platelet-rich plasma (PRP), a modulator of the inflammatory response, has been largely used in veterinary medicine. Here, we investigated the effects of PRP on uterine inflammation, conception rate, endometrial polymorphonuclear neutrophil (PMN) migration, and COX-2 protein levels in the endometrial tissue. Thirteen PMIE-susceptible mares were used for artificial insemination (AI). The mares were inseminated with fresh semen in three consecutive cycl...
Dubuc J, Girard C, Richard H, De Lasalle J, Laverty S.There is limited information available concerning normal equine meniscal morphology, its degeneration and role in osteoarthritis (OA). Objective: To characterise normal equine meniscal morphology and lesions and to explore the relationship between equine meniscal degeneration and femorotibial OA. Methods: Ex vivo cadaveric study. Methods: Menisci were harvested from 7 normal joints (n = 14 menisci) and 15 joints with OA (n = 30 menisci). A macroscopic femorotibial OA score (cartilage degeneration and osteophytosis) was employed to measure disease severity in each compartment. The femoral and t...
Mancini IAD, Vindas Bolaños RA, Brommer H, Castilho M, Ribeiro A, van Loon JPAM, Mensinga A, van Rijen MHP, Malda J, van Weeren R.To report on the experiences with the use of commercial and autologous fibrin glue (AFG) and of an alternative method based on a 3D-printed polycaprolactone (PCL) anchor for the fixation of hydrogel-based scaffolds in an equine model for cartilage repair. In a first study, three different hydrogel-based materials were orthotopically implanted in nine horses for 1-4 weeks in 6 mm diameter full-thickness cartilage defects in the medial femoral trochlear ridge and fixated with commercially available fibrin glue (CFG). One defect was filled with CFG only as a control. In a second study, CFG and ...
Herteman N, Vargas A, Lavoie JP.Low-density neutrophils (LDNs) are a subset of neutrophils first described in the bloodstream upon pathological conditions, and recently, in the blood of healthy humans. LDNs may have an enhanced pro-inflammatory (low-density granulocytes, LDGs) or an immunosuppressive (Granulocytic myeloid-derived suppressor cells, G-MDSCs) profile. Whether these characteristics are specific to LDNs or related to disease states is unknown. Thus, we sought to investigate the properties of LDNs in both health and disease states, and to compare them to those of autologous normal-density neutrophils (NDNs). We st...
Nawrocka D, Kornicka K, Śmieszek A, Marycz K.Equine Metabolic Syndrome (EMS) is a steadily growing life-threatening endocrine disorder linked to insulin resistance, oxidative stress, and systemic inflammation. Inflammatory microenvironment of adipose tissue constitutes the direct tissue milieu for various cell populations, including adipose-derived mesenchymal stromal cells (ASCs), widely considered as a potential therapeutic cell source in the course of the treatment of metabolic disorders. Moreover, elevated oxidative stress induces inflammation in intestinal epithelial cells (IECs)-the first-line cells exposed to dietary compounds. In...
Grzeskowiak RM, Barrett EJ, Rodgerson DH.An 11-year-old Thoroughbred mare with colic unresponsive to medical treatment underwent exploratory laparotomy. During surgery the cecum was found entrapped within the epiploic foramen from left to right. The entrapped cecum was reduced through the foramen by gentle traction. After reduction of the cecum, rupture of the portal vein was detected. Loss of a large amount of blood prompted euthanasia during surgery. Une jument Thoroughbred âgée de 11 ans atteinte de coliques ne répondant pas au traitement médical a subi une laparatomie exploratoire. Durant la chirurgie, le cæcum a été trou...
Mills JS, Kinsley MA, Peters DF, Weber PSD, Shearer TR, Pease AP.The purpose of this study was to determine whether there was a correlation between circulating and intra-synovial Dkk-1 and radiographic signs of equine osteoarthritis. Methods: Circulating and intra-synovial Dkk-1 levels were measured in clinical cases using a commercially available human Dkk-1 ELISA. Radiographs were performed of the joints from which fluid was collected and these were assessed and scored by a boarded radiologist for joint narrowing, subchondral bone sclerosis, subchondral bone lysis, and periarticular modelling. Comparisons were made between radiographic scores and the conc...
Robinson CS, Singer ER, Piviani M, Rubio-Martinez LM.Synovial sepsis in horses is life threatening and accurate diagnosis allowing prompt treatment is warranted. This study assessed the diagnostic value of serum amyloid A (SAA) and D-lactate in blood and synovial fluid (SF) as diagnostic markers of synovial sepsis in horses and correlated them with total nucleated cell count (TNCC), percentage of neutrophils (%N) and total protein (TP) in SF. Blood and SF SAA and D-lactate concentrations were determined in a case-control observational study including 112 horses (38 with synovial contamination or sepsis (SCS), 66 with non-septic intra-synovial pa...
Siemieniuch MJ, Gajos K, Kozdrowski R, Nowak M.Even if mares continue to breed up to an advanced age, in aging mares reproductive failure is quite common. Subclinical endometritis, which occurs more often in aging mares than in younger counterparts, may cause prolongation or shortening of the inter-estrus period or the corpus luteum lifespan. We hypothesized that during subclinical endometritis the secretion of selected arachidonic acid metabolites may differ in aging mares compared to younger females. To verify this thesis, ex vivo organ cultures of endometrium were established with subsequent measurements of concentrations of prostaglan...
Bauck AG, Grosche A, Morton AJ, Graham AS, Vickroy TW, Freeman DE.OBJECTIVE To examine effects of continuous rate infusion of lidocaine on transmural neutrophil infiltration in equine intestine subjected to manipulation only and remote to ischemic intestine. ANIMALS 14 healthy horses. PROCEDURES Ventral midline celiotomy was performed (time 0). Mild ischemia was induced in segments of jejunum and large colon. A 1-m segment of jejunum was manipulated by massaging the jejunal wall 10 times. Horses received lidocaine (n = 7) or saline (0.9% NaCl) solution (7) throughout anesthesia. Biopsy specimens were collected and used to assess tissue injury, neutrophil inf...
Randleff-Rasmussen PK, Mosca M, Knoerr F, Pin D, Desjardins I.Mycetoma is a chronic, proliferative lesion of cutaneous/subcutaneous tissue characterized by draining tracts and granules in the discharge caused by actinomycetes (actinomycetoma) or filamentous fungi (eumycotic mycetoma). Objective: This case report describes the unusual finding of a cutaneous mycetoma of the lateral wing of the right nostril in a gelding. Methods: A 16-year-old Fjord gelding with suspected pituitary pars intermedia dysfunction (PPID) was presented for evaluation of a nonpainful, firm and raised mass involving the lateral wing of the right nostril and the lip. Results: Cytol...
Horses affected by chronic piroplasmosis may develop poor performance and muscle atrophy. Here we investigate the pathological and immunopathological aspects of myopathy occurring in chronic equine piroplasmosis. The study included 16 horses serologically positive for equine piroplasms presenting with clinical signs and supporting serum biochemical evidence of a myopathy. Skeletal muscle was evaluated by histopathology, immunohistochemistry, indirect immunofluorescence, and molecular detection of piroplasms and inflammatory cytokines in skeletal muscle. Histologic lesions included muscle fiber...
Lane MJ, Pucheu-Haston CM, Kearney MT, Woodward M.Appropriate allergen threshold concentrations (TCs) for intradermal testing (IDT) have not been established in horses for many pollen and mould allergens. Objective: To determine the TCs in non-allergic horses and describe the frequency of late phase reactions for 26 allergens, including trees, grasses, weeds and moulds in horses residing in the southern Unites States. Methods: Twenty four clinically normal horses in the southern United States. Methods: Threshold concentrations for different allergens were determined using IDT subjective measurements at 30 minutes. Delayed reactions were evalu...
Campbell MLH, Hampshire D, Hamstead LE, Rose BV, Smith KC, de Mestre AM.Intrauterine infusion of peanut oil at Day 10 post-ovulation has been reported to prolong dioestrus in mares. However, the effects of peanut oil treatment on the endometrium and whether the technique is painful have not been assessed. The objectives of this study were, (i) to determine the effect of intrauterine infusion of peanut oil on endometrial health, (ii) to determine whether use of intrauterine peanut oil is painful and (iii) to confirm that peanut oil causes prolonged dioestrus. Six mares aged 3-12 years old were used in a cross-over design with each mare administered both 1 ml of in...
Menozzi A, Pozzoli C, Poli E, Bontempi G, Serventi P, Meucci V, Intorre L, Bertini S.Nonselective antimuscarinic drugs are clinically useful in several pathologic conditions of horses, but, blocking all muscarinic receptor (MR) subtypes, may cause several side effects. The availability of selective antimuscarinic drugs could improve therapeutic efficacy and safety. We aimed to enlighten the role of different MR subtypes by evaluating the effects of nonselective, and selective M, M and M MR antagonists on the contractions of horse jejunum. Segments of circular muscle of equine jejunum, were put into organ baths, connected to isotonic transducers, and the effects on ACh concentr...
Carmona JU, Ríos DL, López C, Álvarez ME, Pérez JE.Platelet-rich plasma (PRP) preparations are used in horses with osteoarthritis (OA). However, some controversies remain regarding the ideal concentration of platelets and leukocytes to produce an adequate anti-inflammatory and anabolic response in the synovial membrane. The aims of this study were to study the influence of leukoconcentrated platelet-rich gel (Lc-PRG) and leukoreduced platelet-rich gel (Lr-PRG) supernatants on the quantitative expression of some proinflammatory and anabolic genes in equine synovial membrane explants (SMEs) challenged with lipopolysaccharide (LPS). SMEs from six...
Fukuda K, Miyata H, Kuwano A, Kuroda T, Tamura N, Kotoyori Y, Kasashima Y.Platelet-rich plasma (PRP) therapy is promising for treating skeletal muscle injuries in human athletes by promoting muscle regeneration. It might also be useful for treating muscle injuries in equine athletes. In the present study, muscle regeneration induced by injection of PRP into intact muscle of Thoroughbred was investigated. Autologous PRP and saline were injected twice into intact left and right gluteus medius muscles of seven clinically healthy Thoroughbreds. Muscle samples were collected from the injection sites by needle biopsy at 2 and 7 days after PRP injection. Immunohistochemica...
Hill JA, Cassano JM, Goodale MB, Fortier LA.OBJECTIVE To determine whether major histocompatability complex (MHC) class II expression in equine mesenchymal stem cells (MSCs) changes with exposure to a proinflammatory environment reflective of an inflamed joint. SAMPLE Cryopreserved bone marrow-derived MSCs from 12 horses and cartilage and synovium samples from 1 horse euthanized for reasons other than lameness. PROCEDURES In part 1 of a 3-part study, the suitability of a quantitative reverse transcriptase PCR (qRT-PCR) assay for measurement of MHC class II expression in MSCs following stimulation with interferon (IFN)-γ was assessed. I...
Kološ F, Bodeček Š, Žert Z.To describe and report preliminary outcomes of a contralateral trans-nasal endoscopic laser fenestration of the conchae for endoscopic examination and treatment of paranasal sinuses in horses. Methods: Cadaveric experimental and prospective clinical study. Methods: Normal cadaveric equine heads (n = 7) and equine patients (horses n = 7, donkey n = 1) diagnosed with sinusitis. Methods: Ex vivo: a video-endoscope containing a diode laser fiber in the working canal was passed through the nostril and retroflexed in the nasopharynx toward the contralateral conchae. Ventral or dorsal con...
Jiménez-Aristizabal RF, López C, Álvarez ME, Giraldo C, Prades M, Carmona JU.To compare the temporal release (over three weeks) of tumor necrosis factor alpha (TNF-α), interleukin 4 (IL-4), IL-1 receptor antagonist (IL-1ra), platelet-derived growth factor BB (PDGF-BB) and transforming growth factor beta-1 (TGF-β1) from two platelet-rich fibrin (PRF) preparations from equine blood obtained at either 240g/8min or 416g/10min. Whole blood from 10 horses was used to obtain PRF clots by two different centrifugation protocols. After 1h of rest, PRF clots were deposited in wells with culture medium, which was changed at 6h, 24h and then every 48h to 21days. Cytokines and GFs...
Andreassen SM, Vinther AML, Nielsen SS, Andersen PH, Tnibar A, Kristensen AT, Jacobsen S.Septic arthritis is a common and potentially devastating disease characterized by severe intra-articular (IA) inflammation and fibrin deposition. Research into equine joint pathologies has focused on inflammation, but recent research in humans suggests that both haemostatic and inflammatory pathways are activated in the joint compartment in arthritic conditions. The aim of this study was to characterize the IA haemostatic and inflammatory responses in horses with experimental lipopolysaccharide (LPS)-induced joint inflammation. Inflammation was induced by IA injection of LPS into one antebrach...
Kim KH, Park TS, Cho BW, Kim TM.Recent studies have shown that mesenchymal stem cells (MSCs) can play a restorative role against degenerative joint diseases in horses. The purpose of this study was to investigate whether fetal bone marrow-derived cells (BMC)-derived nanoparticles (BMC-NPs) can stimulate the survival of equine chondrocytes. Equine fetal BMCs were isolated and characterized, and the role of BMC-NPs s in equine chondrocytes undergoing inflammatory cell death was examined. BMCs have several characteristics, such as the potential to differentiate into chondrocytes and osteocytes. Additionally, BMCs expressed immu...
Campbell NB, Blikslager AT.Cyclooxygenase inhibitors are administered to horses to prevent endotoxin-induced elaboration of prostaglandins. However, PGE2 and PGI2 stimulate repair of injured intestine. There are 2 isoforms of cyclooxygenase: COX-1, which constitutively produces prostaglandins and COX-2, which is induced by inflammation. We hypothesised that the nonspecific cyclooxygenase inhibitor flunixin meglumine would retard repair of ischaemic intestinal injury by preventing production of reparative prostaglandins, whereas the selective COX-2 inhibitor, etodolac, would permit repair as a result of continued COX-1 p...
Alcott CJ, Sponseller BA, Wong DM, Davis JL, Soliman AM, Wang C, Hsu W.Ketamine has immunomodulating effects both in vitro and in vivo during experimental endotoxemia in humans, rodents, and dogs. Objective: Subanesthetic doses of ketamine will attenuate the clinical and immunologic responses to experimental endotoxemia in horses. Methods: Nineteen healthy mares of various breeds. Methods: Experimental study. Horses were randomized into 2 groups: ketamine-treated horses (KET; n = 9) and saline-treated horses (SAL; n = 10). Both groups received 30 ng/kg of lipopolysaccharide (LPS, Escherichia coli, O55:B5) 1 hour after the start of a continuous rate infusion (CRI)...
Grulke S, Franck T, Gangl M, Péters F, Salciccia A, Deby-Dupont G, Serteyn D.Gastrointestinal disorders, especially strangulating intestinal obstructions, are still a major cause of illness and death in the horse. Circulating lipopolysaccharides may activate both neutrophils and monocytes. The activated neutrophils release myeloperoxidase (MPO), a specific enzyme with strong oxidative activity. The aim of this study was to evaluate MPO concentrations in the plasma and peritoneal fluid (PF) of horses with colic and to check the hypothesis that these concentrations would be higher in a case of strangulating obstruction than in cases of nonstrangulating disease. By using ...
Saari H, Konttinen YT, Tulamo RM, Antti-Poika I, Honkanen V.In addition to its well-known physicochemical properties, hyaluronate (HA) has recently been shown to have important biological and pathophysiologic regulatory effects on granulocytes, monocytes, fibroblasts, and endothelial cells, as well as on the healing of wounds and various joint disorders. Many of these effects depend on or are reflected in the concentration and degree of polymerization of HA. Therefore, high-performance liquid chromatography with size-exclusion column was used to characterize the concentration and degree of polymerization of HA in equine synovial fluid (SF). The mean (+...
Halldorsdottir S, Larsen HJ, Mehl R.Twenty-three Icelandic horses were challenged with extracts of four species of biting midges: Culicoides pulicaris, C chiopterus, C obsoletus and C impunctatus. Fourteen of the tested horses were affected with summer eczema. The horses were challenged intradermally with 0.1 ml of whole-body extracts of midges at a concentration of 0.01 or 0.005 per cent weight/volume. The skin reactions were measured after 30 minutes, 60 or 180 minutes and four, 24 and 48 hours after injection. Antigen titration showed that the reaction was dependent on the antigen concentration. Eight of nine unaffected horse...
Mason JB, Vandenberghe LH, Xiao R, Wilson JM, Richardson DW.To evaluate transduction efficiency of gene therapy for treatment of osteoarthritis in horses. Methods: Cartilage and synovial tissues were aseptically collected from the stifle joints of 3 Thoroughbreds; horses were 3, 7, and 12 years old and free from sepsis and long-term drug treatment and were euthanized for reasons unrelated to joint disease. Methods: Gene transfer experiments were performed with 8 recombinant adeno-associated viral vector (rAAV) serotypes in monolayer-cultured equine chondrocytes, synovial cells, and mesenchymal stromal cells and in cartilage and synovial tissues. Result...
Koivunen AL, Maisi P, Konttinen YT, Prikk K, Sandholm M.The collagenolytic activity and its sensitivity to doxycycline inhibition in tracheal aspirates (TA) of horses with chronic obstructive pulmonary disease (COPD) was analyzed with SDS-PA gel electrophoresis (SDS-PAGE), using Type 1 collagen as the substrate. Both autoactive and total collagenase activities were significantly higher in TAs of horses with symptomatic COPD than in TAs of healthy horses. Doxycycline inhibition studies suggest that most of the TA collagenase is of the neutrophil type (MMP-8), but some is derived from other cells such as fibroblasts and monocyte/macrophages (MMP-1) a...
Souto EPF, Maia LA, Neto EGM, Kommers GD, Junior FG, Riet-Correa F, Galiza GJN, Dantas AFM.The epidemiologic, clinical, pathologic, microbiological and immunohistochemical findings of pythiosis in equidae in northeastern Brazil are described. From January 1985 to December 2020 the Laboratory of Animal Pathology of the Federal University of Campina Grande received 1,331 tissue samples of equidae, 202 (15.17%) of which were diagnosed as pythiosis. Equidae of both sexes with ages varying from 4 months to 25 years were affected. Most animals were mixed breed (79.7%) and reared in an extensive system (73.26%). The disease occurred throughout the year but the highest incidence (70.29%) wa...
Kahn MK, Coverdale JA, Leatherwood JL, Arnold CE, Dabareiner RA, Bradbery AN, Millican AA, Welsh TH.Eighteen Quarter Horses were used in a randomized complete design for a 28-d experiment to evaluate age-related effects on inflammation and cartilage turnover after induction of a single inflammatory insult using lipopolysaccharide (LPS). Horses were grouped by age as yearlings (3 males and 3 females), 2 to 3 yr olds (2/3 yr old; 2 males and 4 females), and skeletally mature 5 to 8 yr olds (mature; 2 males and 4 females). On d 0, all horses were individually housed and fed diets that met or exceeded requirements. On d 14, horses were challenged with an intra-articular injection of LPS. Radial ...
Rosa GDS, Krieck AMT, Padula ET, Stievani FC, Rossi MC, Pfeifer JPH, Basso RM, Braz AMM, Golim MA, Alves ALG.Allogeneic mesenchymal stem cells (MSC) are widely used in clinical routine due to the shorter expansion time and reliability of its quality. However, some recipients can produce alloantibodies that recognize MSCs and activate the immune system, resulting in cell death. Although antibody production was already described after MSC injection, no previous studies described the immune response after intra-articular MSC injection in acute synovitis. This study aimed to evaluate the influence of inflammation on immune response after single and repeated intra-articular injections of synovial membrane...
Plummer CE, Polk T, Sharma J, Bae SS, Barr O, Jones A, Kitchen H, Wilhelmy M, Devin K, Clay Smith W, Kolaczkowski BD, Larkin J.Equine recurrent uveitis (ERU) is a painful and debilitating autoimmune disease and represents the only spontaneous model of human recurrent uveitis (RU). Despite the efficacy of existing treatments, RU remains a leading cause of visual handicap in horses and humans. Cytokines, which utilize Janus kinase 2 (Jak2) for signaling, drive the inflammatory processes in ERU that promote blindness. Notably, suppressor of cytokine signaling 1 (SOCS1), which naturally limits the activation of Jak2 through binding interactions, is often deficient in autoimmune disease patients. Significantly, we previous...
La Perle KM, Piercy RJ, Long JF, Blomme EA.Multisystemic, eosinophilic, epitheliotropic disease and intestinal lymphosarcoma were diagnosed in a Paso Fino mare that presented with anorexia and weight loss. The stomach, ileum, cecum, colon, pancreas, and lungs were infiltrated by large numbers of eosinophils forming prominent eosinophilic granulomas, as well as lymphocytes and plasma cells. Two jejunal masses composed of solid sheets of neoplastic lymphocytes were present. In contrast to the regions of inflammation, the infiltrates in these masses did not contain plasma cells, eosinophils, and eosinophilic granulomas. Immunohistochemica...
Robles M, Peugnet P, Dubois C, Piumi F, Jouneau L, Bouchez O, Aubrière MC, Dahirel M, Aioun J, Wimel L, Couturier-Tarrade A, Chavatte-Palmer P.Feeding pregnant broodmares with cereal concentrates has been shown to increase maternal insulin resistance and affect foal metabolism in the short and long-term. These effects are likely to be mediated by the placenta. Here, we investigated feto-placental biometry and placental structure and function at term in mares fed with or without cereals concentrates. From 7 months of gestation, 22 multiparous mares were fed forage only (group F (n = 12)) or received forage and cracked barley (group B (n = 10)) until foaling. Foals and placentas were weighed and placental samples were collected...
Morán G, Burgos R, Araya O, Folch H.In horses, Recurrent Airway Obstruction (RAO) is an allergic disease that involves IgE mediated Type I Hypersensitivity responses. The development of this type of allergy involves a series of events that begins with reaginic antibodies, mainly IgE and some IgG subclasses. These reaginic antibodies bind with high affinity, via the Fc portion, to FcepsilonRI receptors on the membrane of mast cells and basophils. Once bound, environmental allergens cross-link the antibodies, which results in mast cell degranulation leading to the production of histamine and other chemical mediators that act toget...
Muehlmann LA, Michelotto PV, Nunes EA, Grando FC, da Silva FT, Nishiyama A.Phagocytosis exerted by alveolar macrophages and neutrophils is crucial in the clearance of exogenous particles deposited in the airways. Therefore, substances that activate these phagocytes in the airways can exert important effects on the particle clearance rate. PAF, particularly, was proved to be a potent activator of several immune cells and was shown to be present in the equine lower airways in specific conditions, such as after exercise. The present study aimed to investigate if PAF is able to increase the phagocytic capacity and the production of superoxide anion in equine alveolar mac...
Brankston G, Greer AL, Marshall Q, Lang B, Moore K, Hodgins D, Hennessey JTG, Beeler-Marfisi J.Ambient pollution is associated with the development and exacerbation of human asthma, but whether air pollution exposure is associated with lower airway inflammation in horses has not been fully evaluated. The Air Quality Health Index (AQHI) is an online tool used by asthmatic Ontarians to modify their outdoor activity when ambient pollution is high. A single AQHI value, falling on a scale from 1 to 10, is calculated from measurements of fine particulate matter (PM), nitrogen dioxide (NO), and ozone (O). Increased AQHI values predict an increased risk for presenting to a health care provider ...
Zakia LS, Gomez DE, Caddey BB, Boerlin P, Surette MG, Arroyo LG.Next generation sequencing has demonstrated that alpha diversity of the fecal microbiota is significantly altered in horses with typhlocolitis. The objective of this study was to evaluate the bacterial composition of the cecum content of horses with and without typhlocolitis through direct and culture-enriched 16S gene sequencing of six healthy horses and six horses with acute typhlocolitis; a case-control study design. Cecal content was collected after euthanasia. An aliquot was used for direct 16S gene sequencing. Another was serially diluted with brain heart infusion (BHI) and plated onto f...
Gingerich DA, Auer JA, Fackelman GE.A single intra-articular injection of 20 or 40 mg of purified hyaluronic acid of rooster comb origin resulted in restoration of normal joint function in horses with experimentally induced osteoarthritis. The functional improvement, measured by pressure sensitive force plate techniques, was detectable within one week after treatment and persisted throughout a four week experimental period despite continued use of the joints. The response was dose dependent in that injection of 0 (saline), 5 or 10 mg hyaluronic acid per joint space resulted in no significant change in joint function while dosage...
Arthurs C, Suarez-Bonnet A, Willis C, Xie B, Machulla N, Mair TS, Cao K, Millar M, Thrasivoulou C, Priestnall SL, Ahmed A.Equine penile squamous cell carcinoma (EpSCC) is a relatively common cutaneous neoplasm with a poor prognosis. In this study, we aimed to determine the protein expression and colocalisation of FRA1, c-Myc, Cyclin D1, and MMP7 in normal (NT), tumour (T), hyperplastic epidermis and/or squamous papilloma (Hyp/Pap), poorly-differentiated (PDSCC), or well-differentiated (WDSCC) EpSCC using a tissue array approach. Further objectives were to correlate protein expression to (i) levels of inflammation, using a convolutional neural network (ii) equine papillomavirus 2 (EcPV2) infection, detected using ...
Page AE, Adam E, Arthur R, Barker V, Franklin F, Friedman R, Grande T, Hardy M, Howard B, Partridge E, Rutledge M, Scollay M, Stewart JC, Vale A....The ability to identify horses at risk for catastrophic injuries continues to be a pressing issue for the racing industry, especially given recent events in North America. Objective: Since most catastrophic injuries occur in areas of existing pathology and this pathology is likely to elicit an inflammatory response, it was hypothesised that analysis of messenger RNA (mRNA) expression would detect significant changes in select genes in horses at risk for a catastrophic injury. Methods: Prospective cohort study. Methods: Five racing jurisdictions across the United States participated in this stu...
de la Rebière de Pouyade G, Riggs LM, Moore JN, Franck T, Deby-Dupont G, Hurley DJ, Serteyn D.Laminitis is a local manifestation of a systemic inflammatory response that is characterized by neutrophil activation and movement of neutrophils into the laminar tissues. Given the evidence for the involvement of neutrophils in the development of laminitis, we measured concentrations of neutrophil elastase, a serine protease released from the azurophilic granules of neutrophils, in plasma, skin and laminar tissues obtained from control horses and horses given black walnut heartwood extract (BWHE) to induce laminitis. Healthy horses (5-15 years old) were randomly assigned to 4 groups: 3 experi...
Niedzwiedz A, Borowicz H, Januszewska L, Markiewicz-Gorka I, Jaworski Z.It has been reported that equine recurrent airway obstruction (RAO) is a state of oxidative stress. Oxidant-antioxidant imbalance is known to increase the conversion of deoxyguanosine to 8-hydroxy-2-deoxyguanosine (8-OHdG) in DNA. 8-OHdG can easily be measured using ELISA tests in serum or urine samples. In this study, we analysed serum 8-OHdG levels in horses with recurrent airway obstruction and in healthy controls. Results: The study material consisted of seven healthy horses and seven horses with symptomatic RAO. All horses were exposed to moldy hay and straw for 48 h to induce clinical e...
Takafuji VA, McIlwraith CW, Howard RD.To evaluate the effects of equine recombinant interleukin-1alpha (rEqIL-1alpha) and recombinant interleukin-1beta (rEqIL-1beta) on proteoglycan metabolism and prostaglandin E2 (PGE2) synthesis by equine articular chondrocytes in explant culture. Methods: Near full-thickness articular cartilage explants (approx 50 mg) harvested from stifle joints of a 3-year-old and a 5-year-old horse. Methods: Expression constructs containing cDNA sequences encoding EqIL-1alpha and EqIL-1beta were generated, prokaryotically expressed, and the recombinant protein purified. Near full-thickness articular cartilag...
Wang L, Pawlak E, Johnson PJ, Belknap JK, Alfandari D, Black SJ.To determine whether increased gene expression of a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4) in laminae of horses with starch gruel-induced laminitis was accompanied by increased enzyme activity and substrate degradation. Methods: Laminae from the forelimb hooves of 8 healthy horses and 17 horses with starch gruel-induced laminitis (6 at onset of fever, 6 at onset of Obel grade 1 lameness, and 5 at onset of Obel grade 3 lameness). Methods: Gene expression was determined by use of cDNA and real-time quantitative PCR assay. Protein expression and processing were ...
Benbarek H, Grülke S, Deby-Dupont G, Deby C, Mathy-Hartert M, Caudron I, Dessy-Doize C, Lamy M, Serteyn D.We studied the interactions of isolated equine neutrophils with endothelial cells in culture, mimicking a situation of acute inflammation. Our main purpose was to demonstrate that the supernatant of activated neutrophils was sufficient to damage endothelial cells. Equine endothelial cells (from carotid arteries) were covered either with increased numbers of equine neutrophils stimulated by phorbol myristate acetate, or with the supernatant collected after an in vitro stimulation of the neutrophils. Cytotoxicity was estimated by the release of preincorporated 51Cr, and by light microscopy obser...
Moore RM, Eades SC, Stokes AM.To date, there is a substantial amount of data to support the hypotheses that vascular and enzymatic changes are ongoing in experimental laminitis. Furthermore, there is substantial in vitro evidence that the enzymatic changes weaken the dermo-epidermal attachments leading to mechanical failure of the hoof-bone interface of the equine digit. However, investigators of both the vascular and enzymatic theories have, to date, been unable to substantiate the effects of these pathophysiological changes in vivo on laminar tissues of horses afflicted with experimentally induced or naturally acquired l...
The Journal of nutritionJune 15, 2006
Volume 136, Issue 7 Suppl 2103S-2107S doi: 10.1093/jn/136.7.2103S
Elliott J, Bailey SR.Equine laminitis is the painful and debilitating condition resulting from cellular damage and inflammation of the tissues comprising the bonds supporting the pedal bone within the hoof capsule. One of the reasons why this condition is so complicated and enigmatic is its association with gastrointestinal disturbances, particularly a diet of lush grass at certain times of the year. Determining the link between disturbances to the hindgut flora and pathophysiology in the foot is one of the keys to preventing this condition. Therefore, one of the biggest challenges in equine laminitis research is ...
Ramery E, Fraipont A, Richard EA, Art T, Pirottin D, van Delm W, Bureau F, Lekeux P.Inflammatory airway disease (IAD) affects performance and well-being of horses. Diagnosis is primarily reached by bronchoalveolar lavage (BAL) cytology which is invasive and requires sedation. Objective: The purpose of this study was to identify differential gene expression in peripheral blood of horses with IAD using species-specific expression microarrays. Methods: Equine gene expression microarrays were used to investigate global mRNA expression in circulating leukocytes from healthy, IAD-affected, and low-performing Standardbred and endurance horses. Results: Nine genes in Standardbred and...
Evans DL, Kiddell L, Smith CL.Inflammatory airway disease (IAD) is common in racehorses, and is a cause of wastage in the industry. IAD has been diagnosed by measurement of percent neutrophils (N%) in tracheal aspirates (TA). The aim of this study was to investigate whether spirometric indices of pulmonary function were correlated with N% in TAs. Limits to breathing were measured by analyses of relationships between relative times and relative respiratory gas flows during inspiration and expiration in individual breaths recorded after exercise. Horses with higher N% had significantly lower relative gas flows at the same re...
