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.
Biddle AS, Tomb JF, Fan Z.Due to modern management practices and the availability of energy dense feeds, obesity is a serious and increasingly common health problem for horses. Equine obesity is linked to insulin resistance and exacerbation of inflammatory issues such as osteoarthritis and laminitis. While the gut microbiome is thought to play a part in metabolic status in horses, bacterial communities associated with obesity have yet to be described. Here we report differences in metabolic factors in the blood of obese, normal and lean horses correlated with differences in gut microbiome composition. We report that ob...
Bonilla-Gutiérrez AF, Castillo-Franz C, López C, Álvarez ME, Giraldo CE, Carmona JU.The aim of this study was to evaluate the release of pro- and anti-inflammatory as well as anabolic mediators stimulated by a leukocyte-reduced platelet-rich gel supernatant (Lr-PRGS) and a leukocyte-reduced plasma supernatant (Lr-PL) at two concentrations (25 and 50%) on normal equine suspensory ligament explants (SLEs) and tendon explants (TEs). SLEs and TEs from six horses were independently incubated for 48 h with Lr-PRGS and Lr-PL at concentrations of 25 and 50%, respectively. Samples were collected from the incubated tissues at 1 h and 48 h, which were employed for ELISA determinat...
Young M, Moshood O, Zhang J, Sarbacher CA, Mueller POE, Halper J.Horses afflicted with degenerative suspensory ligament desmitis (DSLD) suffer from progressive leg pain and lameness without history of trauma. DSLD is a systemic disorder caused by abnormal accumulation of proteoglycans in many connective tissues. One proteoglycan found in higher quantities in DSLD is decorin. The accumulated decorin has an abnormally glycosylated glycosaminoglycan chain in DSLD. In addition to acellular accumulations of proteoglycans foci of active fibroblasts/tenoblasts were observed in some tendons and suspensory ligaments (SLs) from DSLD cases We have hypothesized that th...
Ivester KM, Couëtil LL, Moore GE.Mild equine asthma is presumed to arise in response to environmental exposures but the relative impact of differing inflammatory phenotypes upon performance are largely unexplored. Objective: Airway inflammation negatively affects performance and cytological phenotype varies with environmental exposure. Methods: Thoroughbred racehorses in active training and racing. Methods: Thoroughbreds were recruited 24-48 hours before racing. Each horse was eligible for re-enrollment with each race entry. Within one hour of race completion, physical examination, respiratory endoscopy, and BAL were performe...
Lee HG, Choi JY, Park JW, Park TS, Song KD, Shin D, Cho BW.To examine the regulatory effects of exercise on myokine expression in horse skeletal muscle cells, we compared the expression of several myokine genes (interleukin 6 [IL-6], IL-8, chemokine [C-X-C motif] ligand 2 [CXCL2], and chemokine [C-C motif] ligand 4 [CCL4]) after a single bout of exercise in horses. Furthermore, to establish in vitro systems for the validation of exercise effects, we cultured horse skeletal muscle cells and confirmed the expression of these genes after treatment with hydrogen peroxide. Methods: The mRNA expression of IL-6, IL-8, CXCL2, and CCL4 after exercise in skelet...
Schnabel CL, Wemette M, Babasyan S, Freer H, Baldwin C, Wagner B.Chemokines are soluble molecules directing immune cell trafficking and homing, mediating inflammation, and initiating immune responses to infection. In horses, the analysis of chemokines has been limited by the lack of specific antibodies. We generated mAbs specific for the equine C-C motif chemokine ligands (CCL) CCL2 (MCP-1), CCL3 (MIP-1α), CCL5 (RANTES) and CCL11 (eotaxin) using hybridoma technology. Antibody specificity was confirmed by intracellular staining of Chinese Hamster Ovary cells transfected with expression vectors encoding for CCL2, CCL3, CCL5, or CCL11. Transfectants were stai...
Nixon AJ, Grol MW, Lang HM, Ruan MZC, Stone A, Begum L, Chen Y, Dawson B, Gannon F, Plutizki S, Lee BHL, Guse K.Gene therapy holds great promise for the treatment of osteoarthritis (OA) because a single intraarticular injection can lead to long-term expression of therapeutic proteins within the joint. This study was undertaken to investigate the use of a helper-dependent adenovirus (HDAd)-mediated intraarticular gene therapy approach for long-term expression of interleukin-1 receptor antagonist (IL-1Ra) as sustained symptomatic and disease-modifying therapy for OA. In mouse models of OA, efficacy of HDAd-IL-1Ra was evaluated by histologic analysis, micro-computed tomography (micro-CT), and hot plate ana...
Fillion-Bertrand G, Dickson RP, Boivin R, Lavoie JP, Huffnagle GB, Leclere M.There is evidence that the lung microbiome differs between patients with asthma and healthy humans, but the effect of environmental conditions and medication is unknown and difficult to study. Equine asthma is a naturally occurring chronic airway disease characterized by reversible airway inflammation and bronchoconstriction upon exposure to inhaled antigens. In the present study, we evaluated the effect that environmental conditions and disease status have on pulmonary, nasal, and oral microbiomes. Six asthmatic and six healthy horses were studied while at pasture ("low antigen exposure"), as...
Koch DW, Easley JT, Nelson BB, Delcambre JJ, McCready EG, Hackett ES.Auditory tube diverticula, also known as guttural pouches, are naturally occurring dilations of the auditory tube in horses that communicate with the nasopharynx through a small ostium. Infection and select other conditions can result in inflammation and narrowing of the nasopharyngeal ostium, which prevents drainage of fluid or egress of air and can lead to persistent infection or guttural pouch tympany. Auditory tube diverticulotomy allows continuous egress from the auditory tube diverticula and is a feature of disease treatment in horses, in which medical treatment alone is not successful. ...
Knych HK, Arthur RM, McKemie DS, Baden R, Oldberg N, Kass PH.Flumetasone is a potent corticosteroid reportedly used in horses to decrease inflammation associated with strenuous exercise. There are currently no reports describing the use of this drug in horses. Objective: To describe the pharmacokinetics and effects on cortisol and eicosanoid concentrations, following administration of flumetasone to exercised horses. Methods: Parallel design. Methods: Twelve exercised horses received a single i.v. administration of 5 mg of flumetasone. Blood and urine samples were collected before and for 72 h post-drug administration for determination of flumetasone an...
Loeffler A, Herrick D, Allen S, Littlewood JD.Allergic pruritus and urticaria in the horse are challenging for veterinarians and owners; little is known about their long-term management. Objective: To summarize intradermal allergen test results (IDT), and to assess owners' perceptions of skin disease and the effects of medical treatment and management changes in their atopic horses over time. Methods: Eighty two horses with atopic dermatitis in southeastern England between 2006 and 2011. Methods: The IDT results were reviewed retrospectively. Owners completed telephone questionnaires on skin changes, medication, effect of allergen-specifi...
Colbath AC, Dow SW, Hopkins LS, Phillips JN, McIlwraith CW, Goodrich LR. The effects of recombinant interleukin-1β (rIL-1β) have been described for the middle carpal joint (MCJ). However, we are unaware of any studies that have described the cytological response of the tibiotarsal joint (TTJ) to rIL-1β or compared the clinical and cytological responses of the MCJ to the TTJ following the administration of intra-articular rIL-1β. Such information is critical for researchers planning to use rIL-1β to create acute synovitis models in horses. To compare the clinical and cytological responses of the MCJ to the TTJ following administration of intra-articular rIL-1...
Abd El Kader NA, Farghali HA, Abu-Seida AM, Salem NY, Khattab MS.Early detection of cystitis in equine is essential to improve the prognosis and outcome of therapy. However, the conventional white light endoscopy is not sufficiently accurate for this purpose. Hence, this study evaluated chromoendoscopy as a recent diagnostic tool for cystitis in female donkeys. For this purpose, 5 apparently normal donkeys (control group) and 5 female donkeys with cystitis (diseased group) were used. Physical and rectal examinations, urine analysis, white light cystoscopy, methylene blue-based chromoendoscopy and histopathology were performed in all animals. Turbid urine ex...
Trahan RA, Byron CR, Dahlgren LA, Pleasant RS, Werre SR.OBJECTIVE To compare the effects of 3 equimolar concentrations of methylprednisolone acetate (MPA), triamcinolone acetonide (TA), and isoflupredone acetate (IPA) on equine articular tissue cocultures in an inflammatory environment. SAMPLE Synovial and osteochondral explants from the femoropatellar joints of 6 equine cadavers (age, 2 to 11 years) without evidence of musculoskeletal disease. PROCEDURES From each cadaver, synovial and osteochondral explants were harvested from 1 femoropatellar joint to create cocultures. Cocultures were incubated for 96 hours with (positive control) or without (n...
Patan-Zugaj B, Gauff FC, Egerbacher M, Licka TF.OBJECTIVE To investigate the effect of lipopolysaccharide (LPS) on type VII collagen- cleaving matrix metalloproteinases (MMPs) in the lamellar tissue of extracorporeally perfused equine limbs. SAMPLE 10 right forelimbs and 3 left forelimbs collected from 10 adult horses after slaughter at a licensed abattoir. PROCEDURES Extracorporeal perfusion of the isolated equine limbs was performed for 10 hours under physiologic conditions (control-perfused limbs; n = 5) and with the addition of 80 ng of LPS/L of perfusate (LPS-perfused limbs; 5). Lamellar tissue specimens were then collected from the do...
Brandt L, Schubert S, Scheibe P, Brehm W, Franzen J, Gross C, Burk J.Transplantation of multipotent mesenchymal progenitor cells is a valuable option for treating tendon disease. Tenogenic differentiation leading to cell replacement and subsequent matrix modulation may contribute to the regenerative effects of these cells, but it is unclear whether this occurs in the inflammatory environment of acute tendon disease. Equine adipose-derived stromal cells (ASC) were cultured as monolayers or on decellularized tendon scaffolds in static or dynamic conditions, the latter represented by cyclic stretching. The impact of different inflammatory conditions, as represente...
Whitfield-Cargile CM, Chamoun-Emanuelli AM, Cohen ND, Richardson LM, Ajami NJ, Dockery HJ.Non-steroidal anti-inflammatory drugs (NSAIDs) are routinely used in both veterinary and human medicine. Gastrointestinal injury is a frequent adverse event associated with NSAID use and evidence suggests that NSAIDs induce gastrointestinal microbial imbalance (i.e., dysbiosis) in both animals and people. It is unknown, however, whether cyclooxygenase (COX)-2-selective NSAIDs induce dysbiosis, or if this phenomenon occurs in horses administered any class of NSAIDs. Therefore, our objectives were to determine whether the composition and diversity of the fecal microbiota of adult horses were alt...
Cullimore AM, Secombe CJ, Lester GD, Robertson ID.To characterise the relationship between bronchoalveolar lavage fluid (BALF) cytology and pulmonary function testing with histamine bronchoprovocation (HBP) methods in a population of clinically normal horses. Methods: Cross-sectional study METHODS: Clinically normal adult horses (n = 33) underwent pulmonary function testing and HBP with a commercial flowmetric plethysmography system. BAL was performed 1-5 days later. Statistical analysis was used to assess associations between BALF cell concentration, relative inflammatory cell percentages and categorisation, and airway hyper-reactivity...
Beccati F, Pepe M, Antinori L, Pascucci L, Chiaradia E, Mandara MT.The aim of this study was to delineate the pattern of sympathetic innervation in the suprasesamoidean region of the deep digital flexor tendon (DDFT) in horses with tendinopathy by immunohistochemical labelling for tyrosine hydroxylase (TH) and α-1 adrenergic receptor (α1-AR). Twelve forelimbs were obtained from 10 horses with DDFT tendinopathy and six feet obtained from six horses were used as healthy controls. Post-mortem radiographic, ultrasonographic and gross examinations were performed on the suprasesamoidean area of the DDFT to assess the presence of tendinopathy. Longitudinal section...
Barrachina L, Remacha AR, Romero A, Vitoria A, Albareda J, Prades M, Roca M, Zaragoza P, Vázquez FJ, Rodellar C.This study aimed at assessing the effectiveness and safety of repeated administrations of allogeneic bone marrow-derived mesenchymal stem cells (BM-MSCs) primed with tumor necrosis factor (TNF)-α and interferon-γ in an equine model of chemically-induced osteoarthritis. Arthritis was induced in both radio-carpal (RC)-joints by amphotericin-B in 18 ponies, divided into three groups depending on the treatment injected: MSC-naïve (n = 7), MSC-primed (n = 7) and control (n = 4). The study consisted of two phases and used one RC-joint of each animal in each phase, with four months tim...
Mariñas-Pardo L, García-Castro J, Rodríguez-Hurtado I, Rodríguez-García MI, Núñez-Naveira L, Hermida-Prieto M.Osteoarthritis commonly causes lameness in the horse and has a great impact in performance animals. Due to the limitations of current medical therapies, allogenic mesenchymal stem cells (MSCs) may become an alternative method to control inflammation, reduce tissue damage and pain, and therefore improve lameness. We present the results of a regulatory clinical trial testing adipose-derived MSCs (Horse Allo 20) in veterinary (Agencia Española del Medicamento y Productos Sanitarios, Spanish Medicines Agency, Reference number 325/ECV) involving a total number of 80 participants and with 90 days o...
Richardson LM, Whitfield-Cargile CM, Cohen ND, Chamoun-Emanuelli AM, Dockery HJ.To determine whether a cyclooxygenase (COX)-2 selective nonsteroidal anti-inflammatory drug (NSAID) would reduce gastric ulceration and gastrointestinal (GI) inflammation compared with a non-COX selective NSAID. Methods: Randomized block design. Methods: Twenty-five healthy adult horses. Methods: Horses were randomly assigned to receive placebo (n = 5), phenylbutazone (n = 10), or firocoxib (n = 10) administered daily for 10 days. Gastroscopy was performed on days 0 and 10, and both squamous and glandular ulcers were scored according to established scoring criteria. Fecal samples w...
Nichols AEC, Settlage RE, Werre SR, Dahlgren LA.Tendinopathies are common and difficult to resolve due to the formation of scar tissue that reduces the mechanical integrity of the tissue, leading to frequent reinjury. Tenocytes respond to both excessive loading and unloading by producing pro-inflammatory mediators, suggesting that these cells are actively involved in the development of tendon degeneration. The transcription factor scleraxis (Scx) is required for the development of force-transmitting tendon during development and for mechanically stimulated tenogenesis of stem cells, but its function in adult tenocytes is less well-defined. ...
Mainguy-Seers S, Picotte K, Lavoie JP.Tamoxifen, a selective estrogen receptor modulator, decreased airway neutrophilia and improved clinical signs in an experimental model of equine asthma, and induced neutrophilic apoptosis in vitro. Objective: Tamoxifen reduces airway neutrophilia and improves lung function in severe asthmatic horses. Methods: Twelve severe asthmatic horses from a research herd. Methods: Randomized controlled blinded study design. The effects of a 12-day oral treatment with tamoxifen (0.22 mg/kg, q24h) or dexamethasone (0.06 mg/kg, q24h) on lung function, endoscopic tracheal mucus score and bronchoalveolar ...
Valberg SJ, Henry ML, Perumbakkam S, Gardner KL, Finno CJ.An E321G mutation in MYH1 was recently identified in Quarter Horses (QH) with immune-mediated myositis (IMM) defined by a phenotype of gross muscle atrophy and myofiber lymphocytic infiltrates. Objective: We hypothesized that the MYH1 mutation also was associated with a phenotype of nonexertional rhabdomyolysis. The objective of this study was to determine the prevalence of the MYH1 mutation in QH with exertional (ER) and nonexertional (nonER) rhabdomyolysis. Methods: Quarter Horses: 72 healthy controls, 85 ER-no atrophy, 56 ER-atrophy, 167 nonER horses selected regardless of muscle atrophy. M...
Fontenot RL, Langston VC, Zimmerman JA, Wills RW, Sloan PB, Mochal-King CA.To determine meropenem concentrations in radiocarpal (RC) joint fluid and plasma after intravenous regional limb perfusion (IVRLP). Methods: In vivo experimental study. Methods: Nine healthy adult mares. Methods: Meropenem (500 mg) was injected in the forelimb of standing sedated horses via IVRLP with a pneumatic tourniquet inflated to 400 mmHg. Synovial fluid was collected from RC joints at 0, 0.5, 1, 2, 4, 6, 8, 12, and 18 hours after meropenem injection. Blood samples were collected from the jugular vein at the same time points and at 5 and 15 minutes following injection. Meropenem concentr...
Husulak ML, Manning ST, Meachem MD, Burgess HJ, Epp TY, Montgomery JB.The objective of this study was to observe the outcomes of adding an antimicrobial treatment to a conventional treatment regime in horses with severe equine asthma in a clinical setting. Eleven client-owned horses with a history consistent with severe equine asthma, increased respiratory effort and nostril flaring, ≥ 20% neutrophils on bronchoalveolar lavage (BAL), and a positive tracheal wash (TW) bacterial culture were treated with environmental management, corticosteroids, and bronchodilators. Six horses were also treated with an antimicrobial (principal group), while the other 5 were adm...
Anderson JR, Phelan MM, Clegg PD, Peffers MJ, Rubio-Martinez LM.Osteoarthritis (OA), osteochondrosis (OC), and synovial sepsis in horses cause loss of function and pain. Reliable biomarkers are required to achieve accurate and rapid diagnosis, with synovial fluid (SF) holding a unique source of biochemical information. Nuclear magnetic resonance (NMR) spectroscopy allows global metabolite analysis of a small volume of SF, with minimal sample preprocessing using a noninvasive and nondestructive method. Equine SF metabolic profiles from both nonseptic joints (OA and OC) and septic joints were analyzed using 1D H NMR spectroscopy. Univariate and multivariate ...
Varasano V, Marruchella G, Petrizzi L.The healing of wounds located on the equine distal limbs can often be impaired, which can result in exuberant granulation tissue and its associated aesthetic alteration and functional failures. Although a number of therapies have been developed and assessed, the treatment of these wounds still presents challenges. This report describes the treatment of exuberant granulation tissue in a horse using an intra-lesional injection of 4% formaldehyde solution. The successful outcome of this treatment suggests that further investigations are required in order to better evaluate its efficacy, as well a...
du Preez S, Raidal SL, Doran GS, Prescott M, Hughes KJ.Exhaled breath condensate (EBC) analysis is a noninvasive method to assess the lower respiratory tract. In human subjects, EBC hydrogen peroxide (H O ), pH and leukotriene B (LTB ) are useful for detection and monitoring of inflammatory lung diseases, including asthma. Objective: To determine associations between EBC biomarkers and cytological and endoscopic definitions of lower airway inflammation (LAI) while controlling for sampling and environmental variables. Methods: Prospective, cross-sectional study. Methods: Clinical, endoscopic and airway cytological findings from 47 horses were compa...
Maloney SE, Khan FA, Chenier TS, Diel de Amorim M, Anthony Hayes M, Scholtz EL.Proteomic analysis of mare uterine flush fluid provides a minimally invasive technique for studying protein changes associated with the oestrous cycle. The aim of this study was to identify differentially abundant proteins in the uterine flush fluid of mares in oestrus and dioestrus. In this study, uterine flush fluid samples were collected from eight reproductively healthy mares in either oestrus (n = 5) or dioestrus (n = 3). Proteomic analysis was performed using liquid chromatography-tandem mass spectrometry. Of 172 proteins identified, six proteins (immunoglobulin lambda-like polypepti...
Gaustad G, Larsen S.A randomised double blind and placebo controlled clinical study was carried out. Standardbred trotters (n=77), age 3-4 years) with moderate to severe lameness were grouped according to number of affected joints and, within each group, were randomised for treatment with polysulphated glycosaminoglycan (PSGAG), sodium hyaluronate (SH) or placebo for 3 weeks. The horses were inspected weekly with a final examination 2-4 weeks after the end of treatment. Mean initial lameness score was significantly reduced during treatment and at the last examination in all 3 groups (P<0.01). Additionally, the...
Meschter CL, Gilbert M, Krook L, Maylin G, Corradino R.Phenylbutazone, a nonsteroidal anti-inflammatory drug known to produce gastric ulcers, was administered intravenously (13.46 mg/kg body weight) daily to 12 horses. Horses were euthanatized daily after 24, 48, 72, and 96 hours following the initial injection. Eight untreated horses served as controls. Small multifocal pyloric erosions were seen after 24 hours and then progressed in severity over time. The erosions were characterized by sloughing of the surface epithelium, subepithelial bleb formation, necrosis of the lamina propria, degeneration of the walls of subsurface capillaries, and micro...
Clegg PD, Carter SD.A study was performed to identify the activation status of the gelatinase MMPs, MMP-2 and -9, in both normal and diseased equine articular tissues. In addition, the production and activation status of equine MMP-2 and -9 by equine articular cells and tissues in response to increasing IL-1beta concentrations was assessed. The study was performed to test the hypothesis that activation of MMPs is a fundamental step in the pathogenesis of joint diseases; and that this activation is mediated by the cytokine IL-1. Using purified equine MMP-2 and -9, the molecular weights of the zymogen and activated...
Bond SL, Greco-Otto P, MacLeod J, Galezowski A, Bayly W, Léguillette R.Mild asthma in horses decreases racing performance and impairs gas exchange. The efficacy of treatment on performance is unknown. Objective: Treatment targeting lung inflammation improves V ˙ O2 peak in horses with mild asthma. Methods: Thoroughbred polo horses (n = 12) with smoke-induced mild asthma. Horses were exposed to increased ambient particulate matter (35.51 μg/m3 [PM2.5 ]; day mean, centrally measured) from day -33 to 0, from bushfire smoke (natural model). Methods: Prospective, randomized, placebo-controlled, double-blinded clinical trial. All horses completed 3 V ˙ O2 peak t...
McKenzie HC, Murray MJ.To compare concentrations of gentamicin in serum and bronchial lavage fluid after IV and aerosol administration of gentamicin to horses. Methods: 9 healthy adult horses. Methods: Gentamicin was administered by aerosolization (20 ml of gentamicin solution [50 mg/ml]) and IV injection (6.6 mg of gentamicin/kg of body weight) to each horse, with a minimum of 2 weeks between treatments. Samples of pulmonary epithelial lining fluid were collected by small volume (30 ml) bronchial lavage 0.5, 4, 8, and 24 hours after gentamicin administration. Serum samples were obtained at the same times. All sampl...
Gilger BC, Stoppini R, Wilkie DA, Clode AB, Pinto NH, Hempstead J, Gerding J, Salmon JH.To describe the use of episcleral silicone matrix cyclosporine (ESMC) drug delivery devices in horses with immune-mediated keratitis (IMMK) with evaluation of tolerability and efficacy in long-term control of inflammation. Methods: Retrospective study. ESMC implants (1.2 cm length, 30% wt/wt cyclosporine (CsA) in silicone; with approximately 2 μg/day steady-state release for at least 400 days) were used. Results: Nineteen horses (20 eyes) received two or more ESMC implants for superficial stromal (n = 9), midstromal (n = 3), or endothelial (n = 5) IMMK. Three additional horses received two or...
Pycock JF, Allen WE.Exudate and uterine flushings were collected at either 30, 60, 120 or 240 mins after intrauterine infusions of Streptococcus zooepidemicus in genitally normal mares during oestrus. Uteri were also flushed without prior induction of endometritis. Protein concentrations in exudate and flushings increased with time and exudate pH decreased with time; the pH of flushings did not alter. Lysozyme and lactate dehydrogenase were present in flushings from non-infected uteri, but concentrations increased with time after infection. Immunoreactive prostaglandin E2 was undetectable before infection, but co...
Bauquier JR, Forbes G, Nath L, Tudor E, Bailey SR.Acute gastrointestinal disease occurs commonly in horses. Novel biomarkers might improve the understanding of SIRS and aid diagnosis and determination of prognosis. Objective: Increased plasma concentrations of the biomarkers HMGB-1 and nucleosomes are associated with severity of gastrointestinal lesions in horses; concentrations of these biomarkers will be greater in horses with lesions more likely to cause SIRS; and will provide additional information compared with standard biomarkers fibrinogen and SAA. Methods: Thirty horses with gastrointestinal disease, 22 healthy horses. Methods: Prospe...
Moore RM, Bertone AL, Muir WW, Stromberg PC, Beard WL.Effects of low-flow ischemia and reperfusion of the large colon on mucosal architecture were determined in horses. Twenty-four adult horses were randomly allocated to 3 groups: sham-operated (n = 6), 6 hours of ischemia (n = 9), and 3 hours of ischemia and 3 hours of reperfusion (n = 9). Low-flow ischemia was induced in horses of groups 2 and 3 by reducing colonic arterial blood flow to 20% of baseline values. Systemic hemodynamic and metabolic variables were maintained constant and in a normal physiologic range. Full-thickness biopsy specimens were obtained from the left ventral colon for his...
Byron CR, Benson BM, Stewart AA, Pondenis HC.To evaluate the effects of methylprednisolone acetate (MPA) on proteoglycan production by equine chondrocytes and to investigate whether glucosamine hydrochloride modulates these effects at clinically relevant concentrations. Methods: Articular cartilage with normal gross appearance from metacarpophalangeal and metatarsophalangeal joints of 8 horses (1 to 10 years of age). Methods: In vitro chondrocyte pellets were pretreated with glucosamine (0, 1, 10, and 100 microg/mL) for 48 hours and exposed to MPA (0, 0.05, and 0.5 mg/mL) for 24 hours. Pellets and media were assayed for proteoglycan prod...
Eyre P.Systemic anaphylaxis was induced in seven groups of ponies. Systemic hypotension, pulmonary hypotension, and apnea were observed in the control group. Suppression of anaphylaxis was achieved most efficiently with sodium meclofenamate followed by acetylsalicylic acid and diethylcarboamazine. Tripelennamine and methysergide reduced anaphylaxis minimally and burimamide not at all. The findings suggest that histamine and serotonin are of relatively low significance in equine anaphylaxis whereas kinins, prostaglandins and slow reacting substance may be more important.
Medina-Torres CE, Mason SL, Floyd RV, Harris PA, Mobasheri A.The aim of this study was to determine if hypoxia and the hypoxia mimetic cobalt chloride regulate the activity of matrix metalloproteinase (MMP)-2 and -9 in cultures of equine hoof keratinocytes. These effects were assessed in primary cultures of laminar keratinocytes using gelatin zymography. Incubation of keratinocytes with cobalt chloride significantly increased the levels of active MMP-2 compared to untreated controls. Hypoxia significantly increased the expression of active MMP-2 and -9 in keratinocyte cultures. This up-regulation was observed after 6h and peaked at 24h. The study findin...
Collins JA, Moots RJ, Clegg PD, Milner PI.Mature articular cartilage is an avascular tissue characterized by a low oxygen environment. In joint disease, acidosis and further reductions in oxygen levels occur, compromising cartilage integrity.This study investigated how acidosis and very low oxygen levels affect components of the cellular redox system in equine articular chondrocytesand whether the antioxidants resveratrol and N-acetylcysteine could modulate this system. We used articular chondrocytes isolated from nondiseased equine joints and cultured them in a 3-D alginate bead system for 48h in <1, 2, 5, and 21% O2 at pH 7.2 or ...
Offer KS, Dixon CE, Sutton DGM.The sarcoid is the most common equine cutaneous neoplasm. Evidence-based treatment of this condition is often lacking, and selection of treatment modality based on clinical experience or anecdotal evidence. Objective: To assess the quality of the currently available best evidence regarding the treatment of the equine sarcoid. Methods: Systematic review. Methods: In compliance with PRISMA guidelines, literature searches were performed in PUBMED, Web of Science, CAB Abstracts, EMBASE (Ovid) and Scopus in April 2021. Included papers were required to describe an interventional study examining sarc...
Michau TM, Gilger BC.Effects of traumatic injury or inflammation on the equine eye can be catastrophic. These ocular conditions can frequently result in blindness or chronic pain. In addition to blindness and pain, permanent unsightly cosmetic defects can occur. This article addresses options available for improved cosmetic outcome in horses with ocular scars or requiring enucleation. Many of these options have been described in detail previously. New information has been added to the discussion of each option where pertinent.
Durham AE, Smitht KC, Newton JR, Hillyer MH, Hillyer LL, Smith MR, Marr CM.The study was designed to investigate the prognostic value of liver biopsy during investigation of cases of suspected liver disease in mature horses. Objective: That liver biopsy is the most prognostically useful technique in common usage in the investigation of suspected liver disease. Methods: This study examined the prognostic value of liver biopsy during the investigation of suspected liver disease in 73 mature horses. Histopathological variables comprising fibrosis, irreversible cytopathology, inflammatory infiltration, haemosiderin accumulation and biliary hyperplasia were found to be si...
Duesterdieck-Zellmer KF, Driscoll N, Ott JF.To determine concentration-dependent effects of tiludronate on cartilage explants incubated with or without recombinant equine interleukin-1β (rEq IL-1). Methods: Articular cartilage explants from the femorotibial joints of 3 young adult horses. Methods: Cartilage explants were incubated with 1 of 6 concentrations (0, 0.19, 1.9, 19, 190, or 1,900 mg/L) of tiludronate and with or without rEq IL-1 (0.01 ng/mL) for 96 hours. Prostaglandin E(2) (PGE(2)) concentrations in culture medium and explant digests were analyzed via PGE(2) enzyme immunoassay. Sulfated glycosaminoglycan (sGAG) concentration...
Moran G, Buechner-Maxwell VA, Folch H, Henriquez C, Galecio JS, Perez B, Carrasco C, Barria M.Recurrent airway obstruction (RAO, also known as equine heaves) is an inflammatory condition similar to human asthma caused by exposure of susceptible horses to poorly ventilated stable environments. The disease is characterized by neutrophilic airway inflammation, mucus hypersecretion and reversible bronchoconstriction. This inflammatory process is mediated by several factors, including antibodies, cytokines, resident cells of the airway and inflammatory cellular components that arrive in the respiratory tract. An increasing body of evidence has lent support to the concept that a dysregulatio...
Yuan Z, Philbey AW, Gault EA, Campo MS, Nasir L.Papillomaviruses are normally strictly species-specific and even under experimental conditions do not usually infect any other host than the natural host. The only documented reports of natural papillomavirus cross-species infection are of BPV-1/BPV-2, which can infect horses and induce equine sarcoids. BPV DNA has not been detected in non-sarcoid equine tumours or equine papillomas, but its presence has been reported in some cases of equine dermatitis. In the present study, we show that equine inflammatory skin conditions harbour episomal circular double stranded BPV-1 genomes, with copy numb...
O'Neill W, McKee S, Clarke AF.The purpose of this study was to quantify the effect of flaxseed (Linum usitatissimum) supplementation on the skin test response of atopic horses. Six horses that displayed a positive skin test for allergy to extract from Culicoides sp. participated in the 42-day, placebo-controlled, double-blind, cross-over trial. Results showed that supplementation with flaxseed for 42 days in our experimental horses reduced the mean skin test response to Culicoides sp. This observation was concurrent with a significant decrease in the long-chain saturated fatty acids; behenic acid (22:0) and lignoceric acid...
Galen GV, Olsen E, Siwinska N.Creatinine only allows detection of kidney disease when 60 to 75% of the glomerular function is lost and is therefore not an ideal marker of disease. Additional biomarkers could be beneficial to assess kidney function and disease. The objectives are to describe new equine kidney biomarkers. This systematic review assesses the available literature, including the validation process and reference values, following which the authors suggest recommendations for clinical use. SDMA may have some potential as equine kidney biomarker, but there is currently a lack of evidence that SDMA offers any advan...
Mild-moderate equine asthma (MEA) is a common respiratory disorder among racehorses, characterized by lower airway inflammation. Although it is generally agreed that MEA causes poor performance, contrasting results have been reported about the effects of tracheal mucus and the leukocyte populations of the bronchoalveolar lavage (BAL) on performance. This study aims to investigate the associations between airway inflammation and fitness parameters measured during an incremental treadmill test on Standardbred racehorses. For this purpose, the clinical records of 116 Standardbreds subjected to a ...
Hosaka Y, Teraoka H, Yamamoto E, Ueda H, Takehana K.The aim of the present study was to clarify the presence and determine the role of apoptosis in the degenerative process of the superficial digital flexor tendon (SDFT) in the horse. Samples were obtained from normal and inflamed SDFTs of horses. To detect apoptosis and to identify apoptotic cells, the samples were subjected to immunohistochemical labelling and Western blot analysis. Although a large number of cells in degenerate areas showed positive reactions with caspase-3 and single stranded DNA antibodies, cells in normal tendon samples showed very weak reactions. Excessive apoptosis was ...
Belknap JK, Moore JN, Crouser EC.The horse with gram negative sepsis is known to be at particular risk of succumbing to laminitis. This review summarizes recent evidence indicating that similar pathologic events relating to inflammatory injury occur in laminar failure in laminitis as occur in organ injury/failure in human sepsis. The discussion also points out some important differences between the laminae and target organs in human sepsis that impact the clinical nature of the disease.
Kusano K, Ishikawa Y, Seki K, Kusunose R.Inflammatory airway disease (IAD) is a common cause of poor performance, interruption of training and premature retirement in racehorses. It is also reported that up to 80% of horses are affected at some point in the first years of training in UK and Australia. However, no studies with regard to the information on occurrence of IAD in Japanese Thoroughbred racehorses have been reported. To investigate the occurrence and the characteristics of IAD, epidemic research including endoscopic examination of the airway tract and trachea wash was conducted for Thoroughbred racehorses presenting coughs ...
Clarke DL.Chondromalacia of the tracheal and bronchial cartilages and redundancy of the dorsal tracheal membrane result in collapse of the large airways, leading to coughing and airway obstruction. It most commonly affects small-breed dogs, although larger-breed dogs, cats, and miniature horses are also sporadically reported. Dynamic airway imaging is used to confirm the diagnosis. The primary goal of medical management is to control clinical signs attributable to coughing and airway inflammation. When this is no longer effective, tracheal stents provide a minimally invasive, rapid way to restore airway...
Wobeser BK, Godson DL, Rejmanek D, Dowling P.A protozoal parasite identified as Neospora hughesi was found in inflammatory lesions in the central nervous system of a Canadian-born adult horse presented with neurological signs. This is believed to be the first case of equine protozoal myeloencephalitis (EPM) caused by Neospora hughesi in a horse outside of the United States. Un parasite protozoaire identifié comme a été trouvé dans les lésions inflammatoires du système nerveux central d’un cheval adulte né au Canada présentant des signes neurologiques. On croit qu’il s’agit du premier cas d’encéphalomyélite protozoai...
McGorum BC, Dixon PM.Local transendoscopic endobronchial antigen challenge, which has proved to be a valuable clinical and research technique in the study of human pulmonary hypersensitivity, was evaluated in control and asymptomatic COPD--affected horses. Transendoscopic endobronchial challenges with phosphate-buffered saline (PBS), Micropolyspora faeni extract at 60 and 600 micrograms/ml and mouldy hay extract elicited neutrophilic airway inflammatory responses in control (N = 5-7) and asymptomatic COPD-affected (N = 5-7) horses, as determined by cytological examinations of bronchoalveolar lavage fluid (BALF) ha...
