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.
Treonze KM, Alves K, Fischer P, Hagmann WK, Hora D, Kulick A, Vakerich K, Smith ND, Lingham RB, Maniar S, Reger TS, Zunic J, Munoz B, Prasit P....The purpose of this study was to characterize the alpha(4)beta(1) receptor (CD49d/CD29, very late antigen-4, VLA-4) on circulating equine leukocytes and to evaluate the intrinsic potency of an alpha(4)beta(1) receptor antagonist (Compound B) in the horse. Ultimately, these studies would allow us to determine the suitability of treating recurrent airway obstruction (RAO; heaves) affected horses by blocking the cellular recruitment of lymphocytes and neutrophils into the lung. The data demonstrates the alpha(4)beta(1) integrin is present on horse lymphocytes and neutrophils (fluorescence-assiste...
Ferguson R, van Dreumel T, Keystone JS, Manning A, Malatestinic A, Caswell JL, Peregrine AS.An 8-year-old horse was presented with a submandibular swelling. Biopsy of the lesion indicated granulomatous osteomyelitis due to Halicephalobus gingivalis. In the absence of evidence of involvement of the central nervous system at the time of diagnosis, the horse was treated with ivermectin. Unfortunately, the horse did not survive. Un cheval âgé de 8 ans a été présenté pour une enflure sous-mandibulaire. Une biopsie de la lésion a révélé une ostéomyélite granulomateuse causée par En l’absence de signes d’atteinte du système nerveux central au moment du diagnostic, le c...
Faleiros RR, Nuovo GJ, Belknap JK.Laminar inflammation is one of the earliest events in equine laminitis. Calprotectin (CP), a Damage-Associated Molecular Pattern protein, is overexpressed in inflammatory conditions of human skin. Objective: CP is overexpressed in the laminar epidermis of horses with black walnut extract (BWE)-induced laminitis. Methods: Twenty adult horses. Methods: Experimental study. Horses were allocated to one of 4 groups. BWE was administered to horses in 3 groups, which were sampled 1.5, 3, and 12 hours (LAM) later. CP was visualized by immunohistochemistry. Laminar leukocyte counts and intensity of lam...
Timoney JF, Kumar P.Little is known about entry and subsequent multiplication of Streptococcus equi following exposure of a susceptible horse. This information would have value in design of intranasal vaccines and understanding of shedding and protective immune responses. Objective: To determine entry points and sites of subsequent replication and dispersion of S. equi at different times after intranasal infection or commingling exposure. Methods: Previously unexposed horses and ponies were subjected to euthanasia 1, 3, 20 or 48 h following intranasal inoculation with biotin labelled or unlabelled S. equi CF32. S...
Schwarz B, Burford J, Knottenbelt D.This case report describes a 4-year-old-horse with two cutaneous masses on the right crest of the neck. Biopsy revealed chronic nodular pyogranulomatous dermatitis and panniculitis. Giemsa and periodic acid-Schiff stains showed focal spherical, yeast-like organisms. A diagnosis of cutaneous fungal granuloma was made. The size of the masses decreased after oral treatment with fluconazole for 10 days combined with potassium iodide for 30 days, and the remaining masses were excised by laser. Lesions did not recur at the site. Fungal granuloma should be considered as a differential diagnosis in ho...
Kafarnik C, Rawlings M, Dubielzig RR.To describe the pathomorphological features of corneal stromal invasive squamous cell carcinoma (CSI-SCC) in horses. Methods: A total of 87 equine SCC in the Comparative Ocular Pathology Laboratory of Wisconsin database were retrieved. The signalment and anatomical distribution were summarized. Ten CSI-SCC out of 87 SCCs were further investigated focusing on pathomorphological description. All 10 cases were stained with H&E, periodic acid-Schiff stain and Verhoeff's elastic stain. Results: Four Appaloosas, two Quarter horses, two American Paint, one Pinto and one Thoroughbred horse were affect...
Kusano K, Hobo S, Ode H, Ishikawa Y.Cytology of tracheal aspirates, tracheal endoscopic and blood tests were carried out to 86 Thoroughbred racehorses presenting coughs or poor performance which were suspected to have lower respiratory tract disease (LRTD) to assess the conditions of the disorders. Racehorses were classified into coughing (66 horses) and non-coughing (20 horses) groups based on clinical symptoms. Nine Thoroughbred racehorses without respiratory abnormality were used as controls. Assessment of grades of airway mucus, cytology of tracheal aspirates and serum amyloid A (SAA), fibrinogen (Fbg) and pulmonary surfacta...
Nash DM, Sheldon IM, Herath S, Lane EA.Mating-induced endometritis (MIE) is ubiquitous in the horse after natural mating and artificial insemination with frozen/thawed semen causing the most aggressive response. The majority of mares eliminate MIE 24-48 h after insemination. An endometrial explant culture was tested as a potential in vitro exemplar for sperm-induced MIE. Endometrial prostaglandin F(2alpha) (PGF(2alpha)) secretion and expression of interleukin-8 (IL-8) were used as markers of inflammation. Endometrial explants were cultured from uteri collected from follicular phase mares. Explants were challenged with 1 or 10 x 10(...
Muñoz JA, Marcoux M, Picandet V, Theoret CL, Perron MF, Lepage OM.Palatal sclerotherapy using sodium tetradecyl sulfate has been suggested as a treatment for dorsal displacement of the soft palate in young Standardbred horses. The present study evaluated histological and biomechanical changes in the equine soft palate following trans-endoscopic treatment with a low dose of this compound. Two horses were euthanased and examined at 2 weeks and at 1, 2, 4 and 6 months post-sclerotherapy, while two further horses served as untreated controls. The technique was easily performed in all cases without major complications. On histological examination there was no evi...
Reid CJ, Thompson L, Donnelly S, Deaton CM, Marlin DJ, Carrington SD, Irwin JA.Recurrent airway obstruction (RAO) is a chronic inflammatory condition in equine lung, which may share a common immunological basis with human asthma, in which dysregulated Th2 responses occur. Mammals express chitinases and chitinase-like proteins, two of which are active enzymes, chitotriosidase and acidic mammalian chitinase (AMCase). Both enzymes are upregulated in a range of inflammatory conditions, including asthma. We investigated the activity of chitinase in bronchoalveolar lavage fluid from horses with and without RAO in response to organic dust challenges. No significant differences ...
Riihimäki M, Raine A, Elfman L, Pringle J.Airborne factors in a conventionally managed racing stable and markers of pulmonary inflammation in the stabled horses were investigated on 3 occasions at 6-month intervals, including 2 winter periods and the intervening summer period. The stable measurements included inside and outside ambient temperature and relative humidity, levels of total and respirable dust, endotoxin, and 1,3-beta-glucan. Horses (n = 12) were examined in detail clinically as well as by endoscopy, bronchoalveolar lavage (BAL) cytology, and real-time polymerase chain reaction (RT-PCR) analysis of BAL-cells for IL-6 and I...
Germann SE, Richter M, Schwarzwald CC, Wimmershoff J, Spiess BM.A 6-year-old thoroughbred gelding was presented with a history of blepharospasm and opacity in the OS of 1 weeks' duration. Ophthalmic examination findings were consistent with acute uveitis in the OS, and traditional treatment was initiated with systemic antibiotics and anti-inflammatory drugs, topical mydriatics, and corticosteroids. During the total treatment period of 4 weeks response to treatment was weak and the horse developed further problems such as cellulitis of the right hind limb with fever and eventually weight loss and dependent edema. Blood work was indicative of liver disease. ...
Deeg CA.Equine recurrent uveitis (ERU) is a disease with high prevalence and relevance for the equine population, since it results in blindness. Over the last decade, important advancements have been made in our understanding of the underlying immune responses in this disease. ERU is mediated by an autoaggressive Th1 response directed against several retinal proteins. Interphotoreceptor-retinoid binding protein (IRBP) and cellular retinaldehyde-binding protein (CRALBP) are capable to induce ERU-like disease in experimental horses, with the unique possibility to activate relapses in a well-defined mann...
Cook VL, Neuder LE, Blikslager AT, Jones SL.The effect of lidocaine on in vitro migration and adhesion of equine neutrophils was evaluated. Neutrophils were isolated from equine whole blood using a Percoll-gradient centrifugation protocol. Purified neutrophils were incubated with lidocaine at concentrations from 0.1 to 1000 microg/ml for 30 min at 37 degrees C, after calcein loading. Neutrophil integrin-mediated adhesion in response to stimulation with 100 nM LTB(4), 100 nM PAF, or 100 ng/ml IL-8, or integrin-mediated migration in response to stimulation with 100 nM LTB(4), 150 nM PAF, or 100 ng/ml IL-8 was assessed. Statistical signifi...
Hilton H, Affolter VK, White SD.The response to treatment with four topical preparations was evaluated in an 11-year-old Morgan horse mare with histologically confirmed quadrilateral cannon hyperkeratosis. Each limb was treated for 30 days with 0.1% tacrolimus ointment, 0.1% adapalene gel, 0.2% phytosphingosine spray or a water-based emollient. Response to treatment was evaluated both histologically and visually. A water-based emollient and 0.1% tacrolimus ointment produced encouraging clinical responses. Pre-treatment histopathology identified marked, mostly compact, hyperkeratosis and follicular hyperkeratosis, most promin...
Epstein K, Short D, Parente E, Reef V, Southwood L.The objective was to characterize ultrasonographic changes in bowel wall thickness, contractility, degree of distension, luminal contents, and peritoneal fluid associated with exploratory celiotomy in normal ponies. Gastrointestinal ultrasonographic examination was performed in 14 ponies on days 1, 3, 5, and 7 after an exploratory celiotomy. Wall thickness, contractility, degree of distension, and luminal contents were recorded for the duodenum and jejunum. Stomach wall thickness and location, cecal wall thickness, and peritoneal fluid location and character were recorded. Peritoneal fluid was...
Kay AT, Bolt DM, Ishihara A, Rajala-Schultz PJ, Bertone AL.To assess analgesia, inflammation, potency, and duration of action associated with intra-articular injection of triamcinolone acetonide (TA), mepivacaine hydrochloride, or both in metacarpophalangeal (MCP) joints of horses with experimentally induced acute synovitis. Methods: 18 horses. Methods: Both forelimbs of each horse were injected with lipopolysaccharide (LPS) 3 times. After the first LPS injection, 1 forelimb of each horse was treated with intra-articular injection of mepivacaine (80 mg; n=6), TA (9 mg; 6), or mepivacaine with TA (same doses of each; 6) 12 hours after the initial LPS i...
Liu T, Nerren J, Liu M, Martens R, Cohen N.Neonates are thought to be generally deficient in production of Th-1-associated cytokines at birth, and thereby more susceptible to bacterial infections. Using neonatal foals as a model, this study examined the age-dependent maturation of both basal and stimulus-induced immune responses, as reflected by the expression of a panel of Th-1-associated and pro-inflammatory cytokines. Results showed that although the basal production of IFN-gamma and IL-6 was impaired (P<0.05) in PBMCs of neonatal foals at birth, the basal production of IL-8, IL-12(p35/p40) and IL-23(p19/p40) were either in exces...
Clutterbuck AL, Harris P, Allaway D, Mobasheri A.The extracellular matrix (ECM) of connective tissue is constantly being remodelled to allow for growth and regeneration. Normal tissue maintenance requires the ECM components to be degraded and re-synthesised in relatively equal proportions. This degradation is facilitated by matrix metalloproteinases (MMPs) and their proteolytic action is controlled primarily by the tissue inhibitors of metalloproteinases (TIMPs). Both MMPs and TIMPs exist in a state of dynamic equilibrium, with a slight excess of one or the other depending on the need for either ECM breakdown or synthesis. Long-term disrupti...
Hawkes CS, Easley J, Barakzai SZ, Dixon PM.There is minimal published information on equine oromaxillary fistulae that are unrelated to cheek teeth (CT) repulsion or on the conservative treatment of these atypical fistulae. Objective: To report equine oromaxillary fistulae unrelated to CT extraction and describe their management in standing horses. Methods: Case details of oromaxillary fistulae of atypical aetiology occurring at 2 referral centres between 2002-2006, including their treatment and response to treatment were examined. Results: Nine cases of oromaxillary fistula were recorded, mainly in aged horses (median 22 years). Fistu...
Lavoie JP, Thompson D, Hamilton E, Debrue M, David F, Hickey G.It has been suggested that many of the beneficial effects of corticosteroids are mediated through mitogen-activated protein kinase (MAPK) p38 inhibition. Objective: To investigate the efficacy of the MAPK p38 inhibitor compound MRL-EQ1 to either prevent (Phase 1) or treat (Phase 2) recurrent airway obstruction (RAO) in horses. Methods: MRL-EQ1 was administered i.v. at a dosage of 0.75-1.5 mg/kg bwt q. 12 h. In Phase 1, susceptible horses in clinical remission were divided into 2 groups (n = 5/group), based on historical values of respiratory mechanics. All horses were entered in the study in p...
Coyne MJ, Cousin H, Loftus JP, Johnson PJ, Belknap JK, Gradil CM, Black SJ, Alfandari D.Equine laminitis is a debilitating disease affecting the digital laminae that suspend the distal phalanx within the hoof. While the clinical progression of the disease has been well documented, the molecular events associated with its pathogenesis remain largely unknown. Using real time quantitative PCR (RT-qPCR), we have investigated the expression of genes coding for proteins containing a Disintegrin and Metalloprotease domain (ADAM), as well as genes encoding the natural inhibitors of these enzymes (tissue inhibitor of metalloprotease; TIMP) in horses with naturally-acquired (acute, chronic...
Staszyk C, Bienert A, Kreutzer R, Wohlsein P, Simhofer H.A poorly described, painful disorder of incisor and canine teeth, variably causing periodontitis, with resorptive or proliferative changes of the calcified dental tissues, has recently been documented in aged horses. No plausible aetiopathogenesis for this syndrome has been recorded. Eighteen diseased teeth from eight horses were examined grossly and microscopically and showed the presence of odontoclastic cells by tartrate resistant acid phosphatase (TRAP) staining. A chronological sequence of odontoclastic resorption followed by hypercementosis was demonstrated and, consequently, the term eq...
Schleining JA, McClure SR, Evans RB, Hyde WG, Wulf LW, Kind AJ.Lameness as a result of joint disease is a major source of decreased athletic performance in the horse. Most treatment protocols include the administration of nonsteroidal anti-inflammatory drugs (NSAIDs). Phenylbutazone, alone or in combination with other treatments, is the most commonly and widely used NSAID, however it has the potential for serious side effects. The introduction of the liposome-based formulation of the NSAID diclofenac has shown promising effect as a safe and convenient treatment for lameness associated with osteoarthritis. The purpose of this study was to evaluate the effe...
Lunn DP, Hurley DJ.The underlying pathogenesis of laminitis clearly depends importantly on inflammatory processes that recruit leukocytes at an early stage in disease. The role of leukocytes in the initiation of laminitis, or as an intermediary factor is currently being investigated using a limited array of models, and future studies require both new reagent and model systems if we are to clearly define how leukocytes propagate this disease. The opportunities presented by this type of research could easily include new and powerful treatment and preventative modalities.
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.
Yin C, Pettigrew A, Loftus JP, Black SJ, Belknap JK.In the septic horse prone to laminitis, a similar activation of the innate immune system appears to occur as reported in the septic human prone to organ failure. Because oxidant injury plays a central role in organ failure occurring due to an overzealous innate immune response in human sepsis, this study was performed to determine whether there was evidence of oxidant stress in the laminar tissue in the early stages of laminitis. 4-Hydroxy-2-nonenal (4-HNE), a lipid aldehyde that forms due to lipid peroxidation occurring during episodes of oxidant stress, readily forms adducts with cellular pr...
Geor R, Frank N.Obesity, insulin resistance, hyperinsulinemia and hypertriglyceridemia are components of an equine metabolic syndrome phenotype associated with increased laminitis risk in horses. Links between these conditions and laminitis must still be elucidated, but human medicine provides candidate mechanisms for future study, including inflammation associated with obesity, vascular compromise induced by insulin resistance, and endothelial dysfunction. Just as metabolic syndrome has been linked to cardiovascular disease in humans, studies are now required to determine the exact mechanisms responsible for...
Robertson TP, Bailey SR, Peroni JF.Equine laminitis is a crippling condition that continues to defy repeated efforts to delineate the precise mechanisms involved and develop effective therapeutic strategies for use in the clinic. In this article, the possible role of dysfunction of the laminar vasculature is discussed, with particular emphasis on the venous side of the laminar microvasculature and the possible role(s) that metabolic syndrome and thrombosis may play in the dysfunction observed in the laminar microvasculature during the development of laminitis.
Noschka E, Moore JN, Peroni JF, Lewis SJ, Morrow JD, Robertson TP.Inflammation and vascular dysfunction occur concurrently during the prodromal stages of equine laminitis. The aim of this study was to provide insights into the role that thromboxane and isoprostanes may play in the development of black walnut heartwood extract (BWHE)-induced laminitis. Horses were divided into two groups, either control or BWHE-administered horses. Plasma concentrations of thromboxane increased transiently after administration of BWHE and coincided with the nadir in white blood cell counts, whereas plasma concentrations of iso-prostaglandin PGF(2alpha) (iso-PGF(2alpha)) did n...
Sullivan SN, Cole SL, Stewart MC, Brokken MT, Durgam S.To investigate the effects of triamcinolone acetonide (TA) and methylprednisolone acetate (MPA) on the viability of resident cells within the fibrocartilage on the dorsal surface of the deep digital flexor tendon (FC-DDFT) and fibrocartilage on the flexor surface of the navicular bone (FC-NB) of horses. Methods: 12 to 14 explants of FC-DDFT and of FC-NB from grossly normal forelimbs of 5 cadavers of horses aged 9 to 15 years without evidence of musculoskeletal disease. Methods: Explants were incubated with culture medium (control) or TA-supplemented (0.6 or 6 mg/mL) or MPA-supplemented (0.5 or...
Rendle DI, Hughes KJ, Farish C, Kessell A.A 6-year-old Standardbred mare that presented with bilateral palpebral swelling and a left corneal ulcer was diagnosed with a multicentric T-cell lymphoma. Other clinical findings included submandibular lymphadenopathy and oedema, pharyngeal oedema and rhinitis. Prior to euthanasia the horse developed keratomalacia, the onset of which was coincidental with the use of high doses of topical and systemic corticosteroids. Although an unusual presentation, palpebral swelling should be considered as a clinical sign of lymphoma.
Secombe CJ, van Eps AW, Bruce M, Lester GD.To investigate the relationship between bronchoalveolar lavage fluid cytology, particularly mast cells, and airway hyper-reactivity in athletic horses presented for poor performance that included a respiratory tract evaluation in two disparate locations in Australia. Methods: Multi-centre, retrospective and prospective cross-sectional study METHODS: Eighty four adult horses underwent both pulmonary function testing and histamine bronchoprovocation with a commercial flowmetric plethysmography system. A bronchoalveolar lavage was performed four to twelve hours later. Bronchoalveolar lavage fluid...
Auer DE, Ng JC, Seawright AA.The effect of oxygen derived free radicals (ODFR) upon the specific viscosity of equine synovial fluid was studied. ODFR were generated either by a mixture of ferrous iron and EDTA (Fe/EDTA) or by a mixture of hypoxanthine and xanthine oxidase (HX/XO). Incubation of the synovial fluid with both free radical generating systems decreased its specific viscosity. When the synovial fluid was incubated with Fe/EDTA the specific viscosity of the synovial fluid was reduced rapidly. By 2 mins, it was 53 +/- 3 per cent of the original specific viscosity and by 30 mins it was reduced to 39 +/- 5 per cent...
Rejnö S.LDH is an intracellular enzyme, which when cells degenerate is released to the extracellular spaces and body fluids. Cells and organs in the mammalian body differ from each other with respect to their LDH isoenzyme patterns. These circumstances have led to the use of LDH isoenzyme determinations in laboratory diagnostic work. In the present investigation total LDH activity and LDH isoenzyme distribution in equine synovial fluid from healthy joints, joints with serous arthritis, osteochondrosis dissecans and arthrosis, were determined. The fluids from the diseased joints differed from normal sy...
Giusto G, Cerullo A, Gandini M.To resolve large colon impactions, frequent enteral administration of large volumes of water (8-10 liters in a 500 kg horse) has been suggested. Furthermore, in large colon volvulus, the simultaneous presence of gastric impaction has been described as a possible predisposing factor. To describe the clinical and surgical features of horses with large colon volvulus associated with aggressive enteral fluid therapy performed to resolve an initial large colon impaction. Records of horses that underwent exploratory laparotomy at the Veterinary Teaching Hospital of Turin between 2012-2019 were revie...
Borunova SF, Tkachev N, Iolchiev B, Artyushina Z, Abramov P, Nikitina M, Silanteva A, Khusnetdinova N, Serezhenkov V.Diseases of the gastrointestinal tract of horses are caused by many factors and have a complex pathogenesis. Developing effective methods of differential diagnostics is of high fundamental and applied importance. The pathogenesis of diseases of the digestive tract of horses accompanied by the development of inflammation and oxidative stress, can be associated with a lack of the nitrogen monoxide which controls many signaling pathways in the body. The level of the nitric oxide (NO) is involved in the regulation of the immune and nervous systems, the tone of all the blood vessels, and the course...
Mazan MR.Inflammatory airway disease and recurrent airway obstruction are 2 nonseptic diseases of the equine respiratory system with a shared cause of exposure to particulate matter. They appear to occupy 2 ends of a spectrum of disease, but are differentiated by history, clinical signs, and response to treatment. Diagnosis can be made by sampling of respiratory fluids and lung function testing. Treatment consists of environmental modification and pharmacologic treatment with systemic or inhaled corticosteroids and bronchodilators.
Krista KM, White NA, Barrett JG, Furr MO, Buechner-Maxwell VA.To quantify peripheral blood neutrophil apoptosis in equine patients with acute abdominal disease (ie, colic) caused by strangulating or nonstrangulating intestinal lesions and compare these values with values for horses undergoing elective arthroscopic surgery. Methods: 20 client-owned adult horses. Methods: Peripheral blood was collected from horses immediately prior to and 24 hours after surgery for treatment of colic (n = 10) or elective arthroscopic surgery (10), and neutrophils were counted. Following isolation by means of a bilayer colloidal silica particle gradient and culture for 24 h...
Oliveira-Filho JP, Monteiro LN, Delfiol DJ, Sequeira JL, Amorim RM, Fabris VE, Del Piero F, Borges AS.Sarcoidosis is a rare equine skin disease characterized primarily by an exfoliative and granulomatous dermatitis but also presenting granulomatous inflammation of multiple systems. The current report presents the clinical and histopathological findings of sarcoidosis in a 16-year-old American Quarter Horse gelding with nested polymerase chain reaction Mycobacterium spp. DNA detection within hepatic and skin samples. Mycobacterium spp. may play a role in the pathogenesis of equine sarcoidosis as has been proposed for human sarcoidosis.
Faleiros RR, Macoris DG, Alves GE, Souza DG, Teixeira MM, Moore RM.The purpose of this study was to observe and characterize colonic and lung lesions in horses subjected to experimental distension and decompression of the small colon. Sixteen healthy adult horses were divided into 2 groups: 9 horses that were subjected to distension of the small colon by means of a latex balloon surgically implanted in the lumen and inflated to a pressure of 40 mm Hg for 4 h, and 7 horses in which the balloon was implanted but not inflated. Colonic biopsy specimens were collected before balloon implantation, at the end of the period of obstruction, and 1.5 and 12 h after deco...
Moran G, Folch H, Henriquez C, Ortloff A, Barria M.Reaginic antibodies (IgE and some IgG subclasses) and mast cells play important roles in the induction of type I immediate hypersensitivity reactions. These antibodies bind through their Fc fragment to high affinity receptors (FcεRI) present in the membrane of mast cells and basophils. The cross-linking of the receptor initiates a coordinated sequence of biochemical and morphological events that results in exocytosis of secretory granules containing pre-formed inflammatory mediators, secretion of newly formed lipid mediators, and secretion of cytokines. Previously, several studies have invest...
Acland HM, Kenney RM.Twenty-three mares were infected with contagious equine metritis organism by intrauterine inoculation, and necropsied after intervals of two to 116 days. Severe diffuse subacute salpingitis was seen in one mare, and mild multifocal subacute salpingitis was common. Severe diffuse endometritis and cervicitis initially were acute and became more severe, subacute and predominantly plasmacytic by 14 days, then declined but persisted as mild diffuse or multifocal inflammation for the rest of the experimental period. Vaginitis arose in parallel but resolved after 70 days. There were no lesions in the...
Marshall C.Erythema multiforme is reported for the first time in 2 South African horses. Both horses displayed a sudden, fulminant outbreak of raised, non-alopecic and non-pruritic plaques over the dorsolateral aspects of the neck and trunk. In both cases the distribution of the lesions was bilaterally symmetrical. Histopathological findings included hydropic degeneration of basal epidermal cells, eosinophilic necrosis of individual or groups of keratinocytes, intra-epidermal and sub-epidermal cleft formation and mixed, dermal, perivascular infiltrates. An initiating cause could not be identified in eith...
Knych HK, Harrison L, Chouicha N, Kass PH.Intra-articular use of corticosteroids is commonplace in performance horses. Isoflupredone acetate (IPA) is one of four Food and Drug Administration approved corticosteroids for intra-articular use in horses. The lack of published reports describing the efficacy and duration of effects of this drug warrant further study. Objective: To assess the effects of intra-articular administration of IPA on the expression of selected anti- and pro-inflammatory and structural matrix genes following intra-articular administration to exercised Thoroughbred horses and to correlate these effects with drug con...
Black SJ.The structure and dynamic nature of extracellular matrix is discussed in the context of healthy and diseased tissues particularly the equine digital laminae.
Goodrich LR.Equine orthopedic pain management has become a growing area of interest. Its importance has been emphasized in many studies showing that better pain management results in decreased postoperative complications such as chronic pain, support-limb laminitis, gastric ulceration, and gastrointestinal disease. This review is meant for the surgeon managing orthopedic pain pre-, peri-, and postoperatively.
Thomsen ME, Davis EG, Rush BR.A 5-y-old Paint horse gelding was evaluated for acute laminitis after exposure to black walnut shavings. The gelding's feet were previously soaked in an ice bath continuously for approximately 24 h. Treatment consisted of anti-inflammatory and vasodilator therapy. Serial radiographs revealed progressive palmar deviation of the third phalanx and subsolar abscesses in both forefeet. The gelding developed purulent discharge from the right coronary band and the hoof wall detached circumfrentially. Euthanasia was elected after 54 days. Continual exposure of the gelding's feet to ice water temperatu...
Darien BJ, Sims PA, Stone WC, Schilly DR, Dubielzig RR, Albrecht RM.Volvulus of the ascending colon (ACV) in the horse results in microvascular injury and necrosis of the intestinal mucosa. This study investigated the site and type of microvascular injury which occurs within the mucosa and submucosa following ACV. Histopathology of volvulus treated ponies demonstrated mucosal necrosis with microvascular hemorrhage and thrombosis. Thrombi occurred within the subepithelial capillaries and edema and hemorrhage developed throughout the mucosa and submucosa. Vascular casts allowed 3-D viewing of samples obtained from the entire pelvic flexure and demonstrated two d...
Sweeney RW, Sweeney CR.Horner's syndrome developed in 2 horses after routine jugular venipuncture. Signs included unilateral sweating of the face in both horses and ptosis in 1 horse. The signs resolved within 14 hours. Signs of a perivascular injection did not develop in either horse. Although Horner's syndrome has been reported after perivascular jugular injections these cases illustrate that the syndrome may develop following routine intravenous injections.
Lavoie JP, Carlson GP, George L.Hypertrophic osteopathy was diagnosed in 3 horses and in a pony, ranging in age from 8 to 21 years. There were 2 females, 1 sexually intact male, and 1 gelding. In 3 animals, hypertrophic osteopathy was associated with pulmonary abscesses, bronchogenic squamous cell carcinoma, and ovarian granulosa-cell tumor, respectively, and resulted in death or euthanasia. Duration of the condition ranged from 1 to 4 months. In 1 horse, hypertrophic osteopathy was believed to be secondary to pregnancy, and resolved following uncomplicated delivery of a live foal.
Karagianni AE, Summers KM, Couroucé A, Depecker M, McGorum BC, Hume DA, Pirie RS.Mild-to-moderate equine asthma is prevalent in young racehorses, particularly early in their training period. Although the precise etiopathogenesis remains undetermined, it is possible that the susceptibility of this population might partly reflect an exercise-associated immune derangement at the level of the airway. We performed a genome-wide basal gene expression scan on alveolar macrophages (AMs) isolated from Standardbred racehorses before and after commencement of competition race training with a view to identifying any exercise-associated gene expression modulation consistent with functi...
McGlothlin JA, Lester GD, Hansen PJ, Thomas M, Pablo L, Hawkins DL, LeBlanc MM.An experimental model of ascending placentitis was developed in the mare to characterize the uterine myoelectrical pattern in late gestation and determine how ascending placentitis altered this pattern. In experiment 1, myometrial electrical activity was analyzed during the early morning, late morning and evening hours in four mares in the last 15 days of gestation to identify patterns of activity. In experiment 2, nine mares received intra-cervical inoculations of Streptococcus equi subspecies zooepidemicus. Myoelectrical activity in the early morning and evening hours in these mares was comp...
Sams AE, Weldon AD, Rakestraw P.Three horses were diagnosed as having esophageal inclusion cysts. Clinical signs included dysphagia, swelling of the cervical esophagus, and salivation. Surgical removal of the cyst was attempted in two horses. Both horses survived, but multiple complications occurred, including esophageal fistulation and neurovascular damage. Marsupialization of the cyst was performed in the third horse. The stoma closed 3 weeks after surgery without complications, and endoscopic examination revealed a grossly normal esophagus. Marsupialization may be preferable to surgical removal for treatment of selected e...
Armstrong SK, Raidal SL, Hughes KJ.Three foals, aged between 5 and 10 days, were presented for assessment of lethargy, abdominal pain and joint effusion. Fibrinous pericarditis and pericardial effusion (PE) were recognised in each foal and considered as sequelae to systemic inflammatory response syndrome (SIRS) and suspected or confirmed septicaemia. Unassigned: Diagnosis of pericarditis was made in two foals by echocardiographic examination and analysis of pericardial fluid, and during postmortem examination of the third foal. In both of the foals that underwent pericardiocentesis, PE was an exudate, no bacteria were identifie...
Holbrook TC, Moore JN.Endotoxemia and septicemia are encountered frequently in equine veterinary practice. The deleterious effects of endotoxin are related to the severity of the response of the host's inflammatory system. Consequently, it is imperative that appropriate steps be taken to identify animals at risk of developing endotoxemia or septicemia, and to initiate treatments that will reduce the inflammatory response. This article discusses the anti-inflammatory and immune support of horses and foals with endotoxemia and septicemia.
Summerhays GE.Eight horses with synovial sepsis induced by trauma were treated by arthroscopic/tenoscopic debridement and lavage followed by the implantation of a gentamicin-impregnated collagen sponge. Seven of them responded favourably and were sound six months after treatment. The other underwent a further surgical procedure and recovered. Gentamicin-impregnated collagen sponges appear to be a safe and useful adjunct in the treatment of septic joints and tendon sheaths, and have the advantage of being bioabsorbable.
Gift LJ, Gaughan EM, DeBowes RM, Pintchuk PA, Nickels FA, Foreman JH.Medical records of 11 adult horses with jejunal intussusception examined at 5 veterinary teaching hospitals between 1981 and 1991 were reviewed. Nine of 11 horses had signs of acute abdominal discomfort for < 24 hours, whereas 2 horses had a history of chronic signs. Five of 11 horses had an intraluminal or intramural mass associated with the jejunal intussusception. Two horses died or were euthanatized prior to surgery. Partial jejunal resection and jejunojejunal anastomosis were performed in 9 horses. One horse died during surgery and 2 were euthanatized prior to hospital discharge because o...
Brusie RW, Sullins KE, Silverman DG, Rosenberger JL.Arteriovenous (ischaemic strangulating obstruction, ISO) and venous obstructions (haemorrhagic strangulating obstruction, HSO) were created for 70 min in the small intestine of eight anaesthetised horses, and ISO was created in four horses for 2 h and four horses for 3 h at the sternal and diaphragmatic flexures of the large colon. Five minutes following release of the occlusions, sodium fluorescein 20 per cent (0.5 mg/kg bodyweight intravenously) was administered. Serial quantitative measurements of serosal surface fluorescence of the injured segments and a control segment were made at 2, 10,...