Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Erickson HH, Kitchell RL.In the last 2 decades there have been substantial advances in our knowledge of the scientific basis of the mechanisms of pain. Nociceptors or pain receptors are widespread in the skin and tissues of animals; chemical mediation of nociceptor excitation may provide a key for understanding the peripheral phenomena related to pain. The expression of pain in animals involves multiple ascending and descending branches, as well as specialized pain-signaling mechanisms in the spinal cord. The importance of these different pathways varies with species and circumstances. Endogenous neural systems in the...
Ginther OJ.The equine embryonic vesicle has been shown to be highly mobile prior to day 15, moving from one horn to the other many times per day. In Experiment 1, intrauterine mobility patterns of the vesicle were compared between barren and postpartum mares on days 12, 13, or 14, using an ultrasound instrument. Location of the vesicle (left horn, right horn, body) was determined every five minutes during six two-hour trials in each group. Averaged over all trials, the vesicle moved from one horn to the other 1.1 times per two-hour trial. There were no significant differences between barren and postpartu...
Newman MJ, Beegle KH, Antczak DF.Monoclonal antibodies to equine lymphocyte antigens were produced, using normal peripheral blood lymphocytes as the immunogen and standard hybridoma techniques. Antibody producing hybridomas were detected by a solid-phase enzyme-linked immunosorbent assay. Antibodies produced by 6 cloned hybrids were characterized further by microlymphocytotoxicity, indirect immunofluorescence, and agglutination assays on peripheral blood lymphocytes, platelets, and erythrocytes. Reaction patterns on leukocytes indicated that these antibodies may recognize at least 3 different cell-surface antigens: (1) an ant...
Roser JF, Chang YS, Papkoff H, Li CH.A specific and sensitive homologous radioimmunoassay has been developed for equine prolactin, suitable for measuring prolactin concentrations in serum of horses. The sensitivity of the assay ranged from 0.4 to 0.6 ng/ml and the intra- and inter-assay coefficients of variation averaged 6.9 and 15.4%, respectively, for five doses of hormone. Cross-reactivity with other mammalian and nonmammalian prolactins and growth hormones was less than 20 and 0.3%, respectively. Cross-reactivity with equine growth hormone was less than 0.07%. Equine serum and pituitary extracts showed parallel dilution-respo...
Smith JE, Moore K, Cipriano JE, Morris PG.Occasionally, horses are given large amounts of iron to improve performance. Although iron deficiency could limit erythrocyte production and other functions related to nonhematological tissues, it probably only occurs in blood loss. We have developed an enzyme immunoassay for ferritin in equine sera and evaluated its relationship to iron stored in liver and spleen. Serum ferritin correlated significantly (P less than 0.0001) with the concentration of nonheme iron in the liver and spleen. It increased following iron therapy and decreased after phlebotomy. We conclude that serum ferritin provide...
van Wuijckhuise-Sjouke LA.Meconium constipation is observed in a number of foals during every foaling period. The literature on the clinical picture, methods of treatment and complications, is reviewed in the present paper. In addition, the cases of seventy-five foals are reviewed, in which meconium constipation was suspected and which were submitted to the Internal Disease Department of Large Animals during the period from 1972 to 1982. The clinical picture was found to be due to another disorder in nine cases. Treatment with castor oil and alcohol resulted in discharge of the meconium in fifty-eight cases. Complicati...
Drudge JH, Tolliver SC, Lyons ET.From 1977 to 1981, critical tests were conducted on 10 horses naturally infected with population B strongyles. Drugs tested were: oxibendazole (OBZ), 10 mg/kg of body weight (n = 1); albendazole, 10 mg/kg (n = 1); a mixture of thiabendazole (TBZ), 44 mg/kg and trichlorfon, 40 mg/kg (n = 1); a mixture of TBZ at 44 mg/kg with piperazine (PPZ) at 55 mg of base/kg (n = 1); febantel (FBT), 6 mg/kg (n = 3), 12 mg/kg (n = 1), or 24 mg/kg (n = 1); and pyrantel (PRT) pamoate, 6.6 mg of base/kg (n = 1). Large strongyles, Strongylus vulgaris (9 horses) and S edentatus (5 horses), were effectively removed...
Steckel RR, Page EH, Geddes LA, Van Vleet JF.The effect of low-level direct-current stimulation on skin wound healing in the horse was assessed. Self-sustaining electrical circuits with electrodes were implanted subcutaneously in or near the wound. Stimulation by direct current (10 or 20 microA) was used to determine the effect on equine skin healing. The efficacy of electrotherapy was evaluated by sequentially comparing the clinical appearance of the wound and measuring the size of the granulating wound bed. The histologic appearance of the healing stimulated wounds was compared with that in nonstimulated control wounds created on 9 hor...
Nyack B, Padmore CL, Dunn D, Kufuor-Mensan E, Mobini S.A 10-year-old Tennessee Walker gelding, with a history of progressive weight loss, intermittent colic and lethargy, had a slight fever, tachycardia, tachypnea, pallor, ascites and marked ventral edema. Blood analyses revealed anemia, leukocytosis, neutrophilia with a left shift, lymphopenia, monocytosis, hypoproteinemia and a slightly increased SDH level. Abdominocentesis produced red-orange fluid with many RBC and an increased fibrinogen content. Rectal palpation revealed a large mass in the left caudal abdominal quadrant. The animal died shortly after resection of the mass. The histopatholog...
Adams SB, Lamar CH, Masty J.Bipolar stainless steel electrodes were surgically implanted in 4 ponies to record myoelectrical and mechanical activity of the distal portion of the jejunum and pelvic flexure. After determining normal activity, the effects of neostigmine, xylazine, flunixin meglumine, dipyrone, panthenol, and atropine sulfate were determined. Flunixin meglumine, dipyrone, and panthenol had no effect on the motility of the jejunum or pelvic flexure. Xylazine and atropine sulfate decreased motility of the distal portion of the jejunum and pelvic flexure, with atropine sulfate having a greater effect and lastin...
Driancourt MA, Palmer E.An experiment was carried out on pony mares to establish the time of the oestrous cycle at which ovarian follicles are recruited for ovulation. In one group (n=7), the cycle was interrupted at the preovulatory stage by removing the preovulatory follicle; in another group (n=13) the cycle was interrupted at day 6 of the luteal phase by inducing luteolysis with a prostaglandin injection (PG). In a subgroup (n=7) of those given PG, the ovary not bearing the corpus luteum was removed at the time of injection. A further group (n=6) served as surgical controls. The interval to the next ovulation and...
Williams S, Scott P.Meal contaminated by Datura stramonium seeds at the rate of 0.5% by weight was fed to two horses. Both horses showed clinical signs of depression, anorexia, weight loss, rapid heart and respiration rates, mydriasis, polyuria, polydipsia and diarrhoea. Both recovered with treatment. Maize screenings contaminated by the seeds had been used in the manufacture of the meal.
Engelking LR, Dodman NH, Hartman G, Valdez H.The acute 2-hour effects of isoflurane anesthesia on liver function and biliary excretion were examined in 2 ponies prepared surgically with chronic external biliary fistulas (T-tubes). Studies were conducted 2 to 8 months postoperatively with the enterohepatic circulation held intact between studies. Bile acid infusion IV (8.1 to 8.8 mumol/min) helped maintain bile flow and bile acid and bilirubin excretion during complete biliary diversion throughout each study. Following 3-hour control periods, anesthesia was induced and maintained at 1.3 to 1.5 minimal alveolar concentration plus O2 (spont...
Rubin CT, Lanyon LE.Galileo (1638) observed that "nature cannot grow a tree nor construct an animal beyond a certain size, while retaining the proportions which suffice in the case of a smaller structure". However, subsequent measurement has shown that limb bone dimensions are scaled geometrically with body size (Alexander et al., 1979a), and that the material properties of their constituent bone tissue are similar in animals over a wide range of body weight (Sedlin & Hirsch, 1966; Yamada, 1970; Burstein et al., 1972; Biewener, 1982). If, as suggested in previous scaling arguments (McMahon, 1973; Biewener, 19...
Wagner PC, DeBowes RM, Grant BD, Kaneps AJ, Watrous BJ.Proximal growth plate fractures of the tibia in 4 foals were treated surgically. A medial approach was utilized in 3 cases and a lateral approach in the fourth. Bone screw fixation was achieved with cancellous screws and washers. In 3 cases, the screw shaft crossed the proximal tibial growth plate with no adverse effects. In all animals, there was rapid and cosmetic healing. At 8 to 18 months after surgery, all horses were sound at a walk, trot, and canter.
Bowman KF, Leitch M, Nunamaker DM, Fackelman GE, Tate LP, Park MI, Boles CL, Raker CW.A total of 19 Thoroughbred horses were treated for traumatic disruption of the suspensory apparatus, using either external support of the injured limb, removal of fractured proximal sesamoid bone fragments, metacarpophalangeal arthrodesis, compression screw fixation of the fractured proximal sesamoid bones, application of a cast-brace attached to a transfixation pin inserted through the third metacarpal bone, or combinations thereof. Major complications during the treatment of traumatic disruption of the suspensory apparatus were infection (9 of 19 horses, 47%), large cast sores (10 of 14 trea...
Turner TA, Adams SB, White NA.Fifteen horses were referred to Purdue University or to the University of Georgia because of colic. Each of these horses had small intestine incarcerated through the epiploic foramen. However, signs of pain, gastric reflux, and small intestine distention were not consistent signs, as would have been expected with small intestine strangulation/obstruction. In 10 of the 15 cases, abdominal fluid analysis provided the decisive information needed for surgical intervention. Surgery was performed in 14 cases. The small intestine was incarcerated through the epiploic foramen in a right-to-left direct...
Slusher SH, Freeman KP, Roszel JF.In a review of specimens from 80 mares with concurrently collected endometrial biopsy and cytology preparations, eosinophils were found in 33 specimens from 27 mares. In 22 of 27 mares, there were conditions predisposing to pneumovagina, which presumably led to pneumouterus. Thirty-two of the 80 mares also had conditions predisposing to pneumovagina but no eosinophils in the uterine specimens. Experimental introduction of air into the uterus of 3 mares resulted in eosinophils in their uterine specimens.
Breeze RG, Brown CM, Turk MA.3-methylindole was administered orally and intravenously to horses and ponies in order to determine the ability of this chemical to provide a model of equine pulmonary disease. Both routes produced a severe and sometimes fatal pulmonary disease, characterised by bronchiolitis. Clinical signs developed 48 to 72 h after dosing and were most severe between Days 4 and 10 post dosing. Intravenous administration of 3-methylindole produced lung injury more rapidly and at a lower dose rate than the oral route. It is suggested that the respiratory condition induced by this chemical could become a metho...
Latimer CA, Wyman M, Diesem CD, Burt JK.The anatomy of the nasolacrimal duct of the horse was studied grossly and radiographically, using barium contrast dacryocystorhinography and methyl methacrylate casts. Radiographic contrast studies were performed on 4 specimens and gross dissections were performed on 6 specimens. Dacryocystorhinography accurately delineated the course of the nasolacrimal duct, as was subsequently demonstrated by gross dissection. A 60% barium sulfate suspension produced good radiographic contrast, allowing critical assessment of the anatomic features of the nasolacrimal duct.
Eckersall PD, Beeley JG, Snow DH, Thomas A.The two major polypeptides H (Mr 49,000) and L (Mr 33,000) of equine sweat have been purified by gel filtration and characterised by gel electrophoresis and compositional analysis. Both H and L are glycoproteins containing sialic acid, neutral sugars, N-acetylglucosamine and N-acetylgalactosamine, but the two polypeptides differ considerably in the extent of glycosylation. H and L also differ in amino acid composition, but both contain only low levels of sulphur containing amino acids and histidine. These glycoproteins may behave as surfactants.
Van Heerden J, Reyers F.The clinical signs, response to treatment and features of the spirochaete, Borrelia theileri as was found in a horse with suspected borreliasis are described.
McGavin MD, Fadok VA.Skin biopsy for histologic, immunofluorescent, parasitologic, and bacteriologic examination is a common procedure, but for maximum effectiveness the clinician must realize the importance of precautions to select the correct stage of lesion of different diseases; avoiding creating artifacts during removal and fixation; and give full details of history, clinical diagnosis, and differential diagnoses on the laboratory request sheet. Pathology reports describing the subtleties of histologic changes are difficult to write, particularly if the lesions are not specific. Overly long histologic reports...
Gibson SJ, Polak JM, Anand P, Blank MA, Morrison JF, Kelly JS, Bloom SR.The distribution of VIP-immunoreactivity was studied in the spinal cord and dorsal root ganglia of 6 mammalian species. Immunoreactive fibres and cell bodies were most apparent in the dorsal horn, dorsolateral funiculus, intermediolateral cell columns and the area around the central canal. The distribution of VIP immunoreactivity was similar in all species studied, mouse, rat, guinea pig, cat, horse and the marmoset monkey. There were fewer VIP fibres in the dorsal horn of cervical and thoracic segments than in lumbosacral segments. Using radioimmunoassay this gradient increase was quantitativ...
Borgsteede FH.A comparison was made of the efficacy of Ivermectin administered as an injection and as a paste. Fourteen horses which were naturally infected with small strongyles were divided into three groups. Animals of group 1 received an injection of 5 ml Ivermectin, equivalent to 500 kg bodyweight, horses of group 2 received one injector with Ivermectin as a paste (for 500 kg body weight), a third group remained untreated as a control. Faecal examinations and larval cultures on the day of treatment and 14, 28 and 42 days later showed that both injection and paste had a 100 percent efficacy against matu...
Knych HK, Finno CJ, Baden R, Arthur RM, McKemie DS.The in vivo metabolism and pharmacokinetics of flunixin meglumine and phenylbutazone have been extensively characterized; however, there are no published reports describing the in vitro metabolism, specifically the enzymes responsible for the biotransformation of these compounds in horses. Due to their widespread use and, therefore, increased potential for drug-drug interactions and widespread differences in drug disposition, this study aims to build on the limited current knowledge regarding P450-mediated metabolism in horses. Drugs were incubated with equine liver microsomes and a panel of r...
Moens Y, De Moor A.The carbon dioxide content of respiratory gases may be monitored by the use of an infra-red carbon dioxide analyser. The technique allows continuous and non-invasive recording of important information concerning the ventilatory, circulatory and metabolic states of the anaesthetised horse. Some of the monitoring capabilities of a carbon dioxide analyser (capnograph) are reviewed with illustrations from cases anaesthetised in the authors' clinic. Technical faults in the anaesthetic apparatus and the connections with the "patient" could be readily detected and emergency situations immediately rec...
Lischer ChJ, Bischofberger AS, Fürst A, Lang J, Ueltschi G.Lameness in horses due to pain originating from the proximal metacarpal/metatarsal region remains a diagnostic challenge. In cases of obvious lameness the pain can be localised to this region by diagnostic anaesthesia. Because a variety of disorders can cause lameness in this region different imaging modalities including radiography, ultrasonography and scintigraphy should be used to arrive at an accurate diagnosis. Even though a precise anatomic-pathologic diagnosis can still be an enigma, because not only bone and joints, but also soft tissue structures including the proximal suspensory liga...
McKeever KH, Hinchcliff KW, Cooley JL, Lamb DR.The purpose of this study was to test the hypothesis that furosemide administration before exercise would cause greater increases in plasma arginine vasopressin (AVP) concentration in exercising horses than exercise alone. Six adult, clinically normal, unfit mares underwent three randomly ordered 60 minute standard exercise tests on an equine treadmill to examine the effect of furosemide administration on plasma AVP concentration. In one trial, furosemide (1 mg kg-1) was infused four hours before exercise (FUR-4) and a placebo (10 ml saline) was infused two minutes before exercise; in another ...
Art T, Lekeux P.This study was conducted in order to assess whether exercise- and training-induced cardio-respiratory adjustments are modified during the 10-day period which follows a booster vaccination with an oily adjuvanted inactivated vaccine against influenza and equine herpesvirus-1 (Equiffa). Nine healthy vaccinated thoroughbred horses were used. Six were revaccinated and three were kept as control. All the horses completed a standardised exercise test (SET) that was repeated 4 times, i.e. 10 (SET1) and 2 (SET2) days before revaccination, and 2 (SET3) and 10 (SET4) days after revaccination. During the...
Funkquist P, Sandhagen B, Persson SG, Hedenstierna G, Essén-Gustavsson B, Nyman G.Five Standardbred trotters with red cell hypervolaemia (RCHV) were compared before and after removal of approximately 22% (36 ml/kg bwt) of the total blood volume in order to evaluate the haemodynamic responses, haemorheological alterations and oxygen transport during exercise to fatigue. Data were recorded during submaximal exercise at 4 different speeds on a treadmill and then during continued running at the highest speed step until fatigue. Oxygen uptake (VO2), pulmonary artery pressure (PAP), systemic artery pressure (SAP), heart rate (HR), haematocrit and haemoglobin concentrations (Hb) w...
Morris DD, Crowe N, Moore JN.The purpose of this study was to determine if a structurally novel dual inhibitor of arachidonic acid metabolism, SK & F 86002, would inhibit the endotoxin-induced production of tumor necrosis factor (TNF) activity by equine peritoneal macrophages. Equine peritoneal macrophages were variously pretreated for 0, 0.5 and 2 h with SK & F 86002 at 10(-9) to 10(-4) molar final concentrations or were left untreated. Then, the macrophages were cultured in vitro in the presence of endotoxin (5 ng/mL). Supernatant media were collected after 4 h and stored at -70 degrees C until assayed for TNF a...
Lord CC, Woolhouse ME, Mellor PS.Factors affecting epidemics of African horse sickness in Spain were studied using a mathematical model. The model examined the likelihood of an epidemic after the introduction of the virus, and the effectiveness of vaccination strategies. Two host species (horses and donkeys) and one vector species (the biting midge Culicoides imicola) were included. A stratified random sampling method (Latin hypercube sampling) was used for sensitivity analysis of the likelihood of an epidemic. Systematic variation of vaccination parameters was used to consider alternative control strategies. In general, when...
Hon WK, Ng TB.Equine pancreatic acetone powder was extracted with an acetone-water-HCl mixture. An acid acetone powder resulted by adding a copious volume of acetone to the extract. The powder was subjected to salt fractionation, gel filtration and chromatography on CM-cellulose. Steroidogenic activity, ACTH-like immunoreactivity and opiate receptor binding activity were distributed among the CM-cellulose chromatographic fractions derived from material unretarded as well as from material retarded on Sephadex G-25. The data indicates a separation of steroidogenic and opiate receptor binding activities, and t...
Etcheverrigaray ME, Oliva GA, Zabala Suárez JE.Twenty seven per cent of 238 serum samples obtained from horses with clinical diagnosis were positive for the immunodifusion test, while 17% of the 452 sera obtained from asintomatic horses were positive. Twenty one per cent of the 870 sera studied were positive.
Velásquez J, da Silva LLC, Miglino MA.There are many challenges in teaching veterinary anatomy, such as available classroom time, costs, and difficulties accessing animal cadavers, mainly due to animal welfare concerns. Furthermore, veterinary surgeons and radiologists complain that recent graduates lack anatomical knowledge. On the other hand, the current limitations of face-to-face teaching due to the COVID-19 pandemic suggest that the development of online distance education tools is necessary, mainly in specialties that lack this type of material. Teaching platforms promoting the integration of anatomy with other applied disci...
Mair TS, Stokes CR, Bourne FJ.Lavage techniques were used to obtain secretions from the nasal cavity, trachea and bronchi of conscious horses. The techniques, which utilised fibreoptic endoscopy for recovery of tracheal and bronchial secretions, were well tolerated by the horses. The recovery rates of the lavaged fluids were acceptable, but were lowest for bronchial secretions, and there was minimal contamination by blood. The fluids were analysed for IgG and IgM by single radial immunodiffusion, and for IgA and albumin by rocket immunoelectrophoresis. Relative to albumin there was significantly more IgA and IgM, and signi...
Delbeke FT, Baert K, De Backer P.Urinary and plasma concentrations of the nonsteroidal anti-inflammatory drug tiaprofenic acid were determined following oral and intramuscular administration of a dose of 1 g to five fasted horses. Quantitation was performed by high-performance liquid chromatography (HPLC). The limit of quantitation (LOQ) was 0.1 microg/ml and 0.5 microg/ml in 2 ml plasma and 1 ml urine, respectively. Assay precision and extraction recovery were between acceptable values. Tiaprofenic acid pharmacokinetics were described by non-compartment analysis of the data. Absorption was faster after oral administration as...
van Foreest AW, Wiemer P.Periapical disorders in horses can be treated by resection of the apex. The indications, contraindications, diagnosis, treatment and complications of the intervention are discussed. Four case reports of horses in which apicoectomy with retrograde endodontic treatment was performed are reviewed.
Turner JE, Irvine CH.Administration to mares of the anabolic steroid, methandriol, at the maximum recommended dose (300 mg every 3 weeks) for 1 1/2 years had no effect on reproductive characteristics except for suppression of GnRH-induced LH release and a tendency to suppress basal LH levels and the height of the ovulatory LH surge. A 4-fold increase in dosage caused marked suppression of basal LH, the LH surge, and GnRH-induced LH release. Other reproductive responses were minimally affected. There were no behavioural effects, and no changes in weight occurred when mares were compared with matched controls. Small...