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.
Troedsson MH, Scott MA, Liu IK.Four intrauterine treatment strategies were evaluated for effectiveness in mares that were confirmed to be susceptible to chronic uterine infection. Pretreatment samples were obtained at detection of estrus, and a genital strain of Streptococcus zooepidemicus was infused into the uterus when a preovulatory (> 35 mm) follicle was detected. At 12 hours after inoculation, mares were assigned to 1 of 4 selected treatment groups: autologous plasma, 100 ml (n = 5); potassium penicillin, 5 million U in 100 ml of phosphate-buffered saline solution (PBSS; n = 5); 10 mg of prostaglandin F2 alpha in 1...
Honnas CM, Schumacher J, McClure SR, Crabill MR, Carter GK, Schmitz DG, Hoffman AG.Medical records of 10 horses with olecranon bursitis were reviewed to examine treatments, evaluate a technique for en bloc resection of the bursa in standing horses, and determine outcome of the horses after treatment. Before admission, 6 horses had been treated by needle aspiration of fluid from the mass, followed by injection of corticosteroids. Subsequent treatment for 2 of these 6 horses included open drainage and packing of the cavity with gauze soaked in 7% iodine solution. None resolved after these treatments. After admission to the hospital, 5 horses were treated medically and 5 were t...
Greet TR.Thirty eight horses with epiglottal entrapment were examined. In 29 the dorsally displaced mucosa was split axially with a curved hook knife, per nasum. The condition was also treated by subepiglottal mucosal resection (4 horses) and solely by the administration of an anti-inflammatory throat spray (4 horses). All surgical cases were treated with an anti-inflammatory throat spray and parenteral phenylbutazone. Those horses treated via a laryngotomy incision were box rested until the laryngotomy incision healed. The other horses were restricted to walking and trotting exercise for 10 days befor...
Osborne AC, Carter SD, May SA, Bennett D.An investigation was made into the possible contribution of autoimmune mechanisms to equine arthropathies. Serum and synovial fluid (SF) immune complexes and anti-collagen Type II antibodies were measured, by ELISA, in groups of horses with naturally occurring osteoarthritis (OA), osteochondritis dissecans (OCD), bone fracture, traumatised joints, synovitis, infected joints and non-diseased (control) joints. Significantly raised anti-collagen Type II antibodies were found in osteoarthritic (P < 0.02) and traumatised joint synovial fluids (P < 0.01) compared with the control, where ten of...
Hawkins JF, Ross MW.Medical records of 40 racing Standardbreds with superficial digital flexor tendinitis that underwent transection of the accessory ligament of the superficial digital flexor (SDF) muscle (superior check desmotomy) were reviewed. Surgery was performed bilaterally in 32 horses and unilaterally in 8. Concurrent palmar annular desmotomy was performed in 8 horses in which tendinitis involved the distal metacarpal region and confinement of the deep and SDF tendons by the annular ligament was suspected. Follow-up information was obtained for 32 horses, by telephone, and racing results were available f...
Wang ZW, Yu MF, Robinson NE, Derksen FJ.The present study was conducted to determine if acetylcholine (ACh) release from airway cholinergic nerves is increased and if modulation of ACh release by prejunctional receptors is altered in horses with heaves, an obstructive airway disease characterized by airway inflammation and bronchospasm. Trachealis strips and bronchial segments of normal horses and horses affected with heaves were suspended in 2-ml tissue baths. ACh release was induced by electrical field stimulation and the bath ACh content was measured by high performance liquid chromatography (HPLC) with electrochemical detection....
Baxter GM.Low doses of endotoxin cause vasoconstriction and hypoperfusion of the digit, small intestine, and cecum in horses. To determine the potential cause of these vascular alterations, in vitro vascular responses of palmar digital arteries and veins were determined in 8 horses after intravenous (IV) infusion of 1 L 0.9% NaCl (control) and 0.1 microgram/kg Escherichia coli 055:B5 endotoxin in 1 L of 0.9% NaCl (endotoxin-treated). Vessels were surgically removed under general anesthesia, cut into 4-mm vascular rings, suspended in tissue baths, and attached to force displacement transducers for measur...
Gomez-Cuetara C, Flores JM, Sanchez J, Rodriguez A, Sanchez MA.An histological study of the postpartum period in 29 mares was carried out. Uterine biopsies were taken daily during the first 10 days postpartum in a total of 87 samples. At day 0, equine endometrium was characterized in the surface by the presence of regularly ordered microcaruncles; the stratum spongiosum was oedematous and contained distended and scarce glands. Degenerative changes in microcaruncles and endometrial glands were present on day 1 postpartum. The epithelium of the microcaruncles from 2 to 5 days postpartum showed cytoplasmic vacuolization, karyorrhexis and an inflammatory reac...
Santschi EM, Adams SB, Robertson JT, DeBowes RM, Mitten LA, Sojka JE.Six mares had ovariohysterectomy performed for chronic pyometra associated with cervical abnormalities, uterine neoplasia, or removal of a macerated fetus. Ovariohysterectomy was performed through a ventral midline incision with access to the ovarian and uterine vessels aided by traction on the uterus and retraction of abdominal viscera. Abdominal pain, the most common complication after surgery, occurred in four mares but resolved within 36 hours. Peritonitis occurred in two mares; one mare was subsequently euthanatized. Other complications that resolved with treatment included infection of t...
Raidal SL, Love DN, Bailey GD.Confinement of horses with their heads elevated for periods up to 24 hours was used to evaluate the extent and the effects of bacterial contamination of the equine lower respiratory tract. Significant (P < 0.05) increases in bacterial numbers (up to 10(9) colony forming units/mL in transtracheal aspirate derived samples) occurred within 6 or 12 hours in most horses. Pasteurella/Actinobacillus spp and Streptococcus spp were most commonly isolated. Lowering of the head for 30 minutes every 6 hours to facilitate postural drainage did not prevent multiplication of organisms to levels equivalent...
Sutton RH, Coleman GT.Abstract Extract A 15-year-old pony mare developed firm irregular bony swellings on all four legs. These were most severe around the carpal and fetlock joints of the forelegs, restricting both flexion and extension. Over about 6 months the horse had periodic bouts of coughing. She showed moderate weight loss and a depressed demeanour.
Gosztonyi G, Ludwig H.Natural BD is a nonpurulent acute/subacute encephalitis of horses and sheep with a propensity to involve the olfactory and limbic systems, and the brain stem. The inflammation is concentrated primarily in the gray matter, but subcortical white matter may also be affected. Experimental BD can be produced in a series of animals from birds to primates. The neuropathology after experimental infection is similar to that in natural disease but the inflammatory changes are more diffuse. In the rat and mouse, a persistent/tolerant infection can also be induced, in which inflammatory changes are conspi...
Foster AP, Lees P, Cunningham FM.Hypersensitivity responses to biting flies such as Culicoides are believed to be the cause of sweet itch, a seasonal intensely pruritic skin condition of horses. Little is known about the mediators released by antigen in the skin of affected horses. In the present study the cutaneous vascular and cellular responses to intradermally injected platelet activating factor (PAF) have been characterised in sweet itch cases during the active phase of the disease and compared with those of Culicoides antigen extract. Histamine was used as a positive control in vascular permeability studies. Responses w...
Widders PR, Warner S, Huntington PJ.Normal mares were immunised by the intramuscular and intrauterine administration of an antigen with adjuvant and they and unimmunised control mares were later challenged by the intrauterine instillation of pathogenic Streptococcus zooepidemicus; the response of all the mares was monitored clinically and bacteriologically for seven days. Significantly fewer S zooepidemicus were present in cervical swabs taken from the immunised mares than from the control mares (P < 0.01) and the degree of inflammation in the genital tract of the immunised mares was also significantly less (P < 0.001). Th...
Buergelt CD, Greiner EC.Fibrosing granulomas were found in the liver and occasionally on the intestinal and diaphragmatic serosae and in the lung of 11 horses submitted for necropsy. Although these granulomas were considered incidental findings in most of the horses, they had caused liver failure in 1 horse. The granulomas typically were characterized by a dense collagenous core that frequently was mineralized. The periphery contained a rim of inflammatory cells. Only in 1 of the 11 horses was there evidence of an egg shell suggestive of schistosomes. Schistosomal eggs were not detected in the feces of the horses. Th...
Edwards RB, Fubini SL.Five Holstein calves and two foals with omphalophlebitis were treated by surgical marsupialization of the umbilical vein remnant because complete resection of the infected tract was not possible. The infected umbilical stalk was resected, and the umbilical vein remnant was marsupialized in a one-stage procedure by suturing it into the abdominal wall lateral to the abdominal incision. Antimicrobial drugs were administered, and the marsupialized tract was irrigated until closure by second intention healing. Cellulitis associated with the marsupialization site occurred in two calves but resolved ...
Collatos C, Barton MH, Moore JN.Plasma fibrinolytic activity was evaluated over 5 consecutive days in 59 horses admitted to the Large Animal Teaching Hospital with acute gastrointestinal diseases. Only horses hospitalized for at least 5 days were included in the study. Tissue plasminogen activator (tPA) and plasminogen activator inhibitor type-1 (PAI-1) were quantitated using standard chromogenic activity assays. Statistical analyses were performed using analysis of variance; differences were considered significant when P < or = .05. Activity of PAI-1, the primary endogenous inhibitor of fibrinolysis, was significantly incre...
Gomez-Villamandos RJ, Santisteban Valenzuela JM, Ruiz Calatrava I, Gomez-Villamandos JC, Avila Jurado I.A study was made of the effects of low-level laser irradiation on the cicatrization of superficial wounds in the pharyngeal mucosa of the horse. Methods: Duplicate pharyngeal mucosal ulcers were induced in 12 Spanish horses with submucosal injection of sulfuric acid. A fibroendoscope and an He-Ne laser were used to treat one of the ulcers and the second ulcer in each animal was left untreated, serving as a control. Biopsy samples for the histological study were taken after the seventh laser therapy session from the two animals. Results: Irradiated lesions cicatrized at 10.5 days and nonirradia...
Johannisson A, Gröndahl G, Demmers S, Jensen-Waern M.Methodological aspects of flow-cytometric evaluation of the phagocytic properties of equine neutrophils were elucidated. The kinetics of attachment and ingestion were studied, and the phagocytic process was more rapidly completed when serum-opsonized yeast cells were used than with use of IgG-opsonized yeast cells. Trypan blue was successfully used to quench fluorescence of non-ingested yeast cells. There were only minor differences in the kinetics of phagocytosis between quenched and unquenched samples, indicating that attachment is rapidly followed by ingestion. Trypan blue quenching caused ...
Baxter GM.Laminitis is an inflammation of the sensitive laminae along the dorsal aspect of the digit and is considered to be a secondary complication of several predisposing or primary factors. Affected horses are usually very lame, have increased digital pulses, are painful to hoof testers along the toe of the foot, and have evidence of downward rotation or distal displacement of the distal phalanx present on radiographs. Treatments for acute laminitis include anti-inflammatory drugs, anti-endotoxin therapy, vasodilators, antithrombotic therapy, corrective trimming and shoeing, and surgical procedures....
Rebhun WC.Most ocular and orbital injuries or acute ocular inflammation in horses result in similar signs of adnexal swelling, photophobia, blepharospasm, and lacrimation. It is hoped that detailed examination and the suggestions in this article will enable veterinarians attending horses having ocular emergencies to arrive at a correct diagnosis and appropriate therapy.
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.
Muttini A, Petrizzi L, Tinti A, Bertoluzza A.An investigation was carried out on most common synovial fluid parameters of normal and osteochondritic hocks of horses less than 12 months old in order to confirm the presence of an inflammatory process. Furthermore, a spectroscopic study was performed on synovial fluid from both normal and diseased hocks. A depolymerization of hyaluronic acid was demonstrated in synovial fluid from diseases joints, similar to that reported in human rheumatoid arthritis. A one month rest seem to normalize all parameters considered and in one joint, a return to normal infrared spectrum was demonstrated.
Monahan CM, Taylor HW, Chapman MR, Klei TR.Protection from Strongylus vulgaris infection through immunization with radiation-attenuated third-stage larvae (L3) or crude soluble homogenates from larval or adult stages was examined. Yearling ponies raised parasite-free were divided into 3 immunization groups: radiation-attenuated L3; soluble adult somatic extracts; larval somatic extracts with excretory/secretory products (E/S) from in vitro culture; and 1 medium control group. Ponies were immunized twice; attenuated larvae were administered orally and somatic extracts or controls injected intramuscularly with adjuvant. Approximately 6 w...
Otten N, Marti E, Söderström C, Amtmann E, Burger D, Gerber H, Lazary S.A xanthate compound with antiviral and antitumoural activities, tricyclodecan-9-yl-xanthogenate (D609) in combination with the potassium salt of the lauric acid (KC12) and, in a further investigation, the above-mentioned substances together with recombinant human TNF alpha (rh-TNF alpha), were tested on equine sarcoid tumours for therapeutic efficacy. A pilot investigation on 5 healthy horses showed that the compounds were well-tolerated; apart from a local, temporary oedema at the injection site, no other clinical symptoms were observed after subcutaneous administration of volumes from 0.1 to...
Barton MH, Moore JN.Whole blood from 10 healthy horses was aseptically collected into heparin or citrate anticoagulant and incubated in vitro for 6 hr in the absence (saline control) or presence of 1 ng endotoxin/ml blood. Pentoxifylline (0.1, 1, 10, or 100 micrograms/ml blood) was added 1 hr before, at the same time, or 1 hr after endotoxin. As compared to saline controls, pentoxifylline alone had no effect on mediator production, with the exception of significantly increasing 6-ketoprostaglandin F1 alpha concentration. Pentoxifylline inhibited endotoxin-induced increases in tumor necrosis factor (TNF) and inter...
Bertone AL.Initial management of injuries includes safely gaining control of the animal and assessing and treating systemic shock. If hemorrhage is life threatening, it must be controlled. If the limb is nonfunctional it should be stabilized. Any open orthopedic injury should be treated by cleaning the tissues, protecting the exposed tissues, and administering systemic antibiotics. A commercial splint is available (Equine Regular Leg Saver Splint, Kimzey Welding Works, Woodland, CA) that can immobilize and relieve weightbearing for cases of phalangeal fracture, flexor tendon rupture, fetlock breakdown, a...
Toutain PL, Autefage A, Legrand C, Alvinerie M.The purpose of the present study was to establish in the horse the relationship between plasma concentration profiles of phenylbutazone (PBZ) and flunixin meglumine (FM) and their pharmacological effects in order to build a predictive pharmacokinetic/pharmacodynamic (PK/PD) model. In five horses, an experimental arthritis was induced by injecting Freund's adjuvant into a carpal joint. PBZ (4 mg/kg) and FM (1 mg/kg) were injected by the intravenous route as a single intravenous dose in two different trials. Five pharmacodynamic end-points were regularly measured after test article injection usi...
Traub-Dargatz JL, Schlipf JW, Granstrom DE, Ingram JT, Shelton GD, Getzy DM, Lappin MR, Baker DC.Multifocal myositis was diagnosed in a 7-year-old Quarter Horse gelding on the basis of history and findings on physical examination, serum biochemical analysis, electromyography, and microscopic examination of frozen sections of muscle biopsy specimens. Histologic examination of the muscle specimen revealed multifocal accumulations of histiocytes, lymphocytes, and plasma cells, with attendant myofiber degeneration and necrosis. Parasitic cysts with morphologic characteristics of Sarcocystis sp were found in regions of myocyte degeneration and necrosis, and in regions of normal muscle. Based o...
Griffiths IR, Smith S, Doxey DL, Whitwell K, Love S.Sera from acute and chronic cases of natural grass sickness or normal horses were injected into the parotid salivary gland of ponies. This gland receives its sympathetic innervation from the ipsilateral cranial cervical ganglion. None of the ponies showed any local or systemic signs of illness. After one week the cranial cervical ganglia, stellate and coeliaco-mesenteric ganglia were removed for histological study. Pathological changes were found only in the cranial cervical ganglion ipsilateral to a parotid salivary gland which had received an injection of grass sickness serum. Four out of fi...
Tallmadge RL, Antczak DF, Felippe MJB.Host defenses against infection by viruses, bacteria, fungi, and parasites are critical to survival. It has been estimated that upwards of 7% of the coding genes of mammals function in immunity and inflammation. This high level of genomic investment in defense has resulted in an immune system characterized by extraordinary complexity and many levels of redundancy. Because so many genes are involved with immunity, there are many opportunities for mutations to arise that have negative effects. However, redundancy in the mammalian defense system and the adaptive nature of key immune mechanisms bu...
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...
Przewoźny M, Senderska-Płonowska M, Rząsa A, Wierzbicki H, Borkowski J, Swagemakers JH, Żak-Bochenek A, Stefaniak T.Arthroscopy and splint bone removal are the common orthopedic procedures in horses. Estimation of the dynamics of acute phase proteins in postoperative monitoring seems to be interesting diagnostic approach. The aim of the study was to investigate changes in the concentrations of plasma inflammatory markers-fibrinogen, haptoglobin, and protease inhibitors-following orthopedic surgery in horses. The study involved 114 horses, divided into two study groups undergoing: arthroscopy (41 horses) and splint bone removal (13 horses). The control group consisted of 60 healthy horses. The blood was coll...