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.
Eichhorn W.Infections and clinical diseases caused by equine 2 influenza A viruses are observed worldwide. The frequency of these outbreaks supports the hypothesis that antigenic variation of the surface proteins may play an important role. For the demonstration of these variations, monoclonal antibodies (Mabs) were prepared. They are directed against the hemagglutinin or the neuraminidase of the prototype strain a/eq/Miami/1/63. In hemagglutination-inhibition assays with Mabs two reaction patterns were observed: four Mabs inhibited 14 out of 17 strains tested. Another Mab recognized the hemagglutinin of...
Sentsui H, Kono Y.Horse erythrocytes treated with equine infectious anemia virus hemagglutinin were phagocytized by cultivated horse leukocytes (mainly macrophage-like cells and partly polymorphonuclear cells) after incubation with fresh horse serum but not with inactivated horse serum. The phagocytosis began as soon as the erythrocytes were added to the leukocyte cultures, and the majority of the reaction proceeded within 30 minutes. Addition of antiserum showed a slightly suppressing but no enhancing effect on the phagocytosis. Phagocytosis seemed to be caused by the recognition of the third complement compon...
Charbord P, Tippens D, Wight TS, Gown AM, Singer JW.This report describes an IgG1 mouse monoclonal antibody derived after immunization of mice with washed stromal cells from human, long-term bone marrow cultures. The antigen recognized by the antibody (BMS-1) is a carbohydrate-containing prosthetic group that is common to and specific for multiple horse serum proteins. These proteins are avidly ingested by stromal cells and concentrated in endocytic vesicles. Cultured smooth muscle cells took up the horse proteins in a similar manner to marrow stromal cells while cultured marrow fibroblasts, endothelial cells, and hepatoma cells did not. These ...
Squires EL, McKinnon AO, Carnevale EM, Morris R, Nett TM.For embryos collected from mares 7 days after ovulation, embryo recovery for single-ovulating mares was 53% compared to 106% for double-ovulating mares. Pregnancy rates 50 days after surgical transfer were 68 and 129%, respectively. Concentrations of LH were similar during the periovulatory period for cycles which included single or double ovulations. Horse pituitary extract given for 5.5 days resulted in greater than or equal to 2 ovulations (mean 3.8) in 26 of 28 mares and 2.0 embryos were recovered per donor compared to 0.65 for controls. Non-surgical pregnancy rates for embryos collected f...
Watson ED, Stokes CR, David JS, Bourne FJ, Ricketts SW.Intrauterine infusion of 1 per cent oyster glycogen solution was used to induce acute endometritis in four genitally normal mares. Numbers of viable neutrophils recovered in uterine washings had increased by 1 h after infusion and remained elevated for at least 72 h. There was a significant correlation between numbers of viable neutrophils and total protein concentrations and between prostaglandin (PG)F and PGE2 concentrations in washings. There was also a significant relationship between concentrations of 15-keto-13, 14-dihydro PGF2 alpha in plasma and PGF in washings. Intrauterine concentrat...
Vandeplassche MM.From a total of 601 severe dystocias in mares, 408 (68%) of the fetuses were in anterior, 95 (16%) in posterior and 98 (16%) in transverse presentation, compared with 99%, 1% and 0.1% respectively for spontaneous parturitions. From the cases with anterior presentation, 151 (37%) showed reflected heads and necks. From the cases with posterior presentation, 47 (50%) presented hip flexions, 25% had hock flexions, and 25% had stretched hind legs, 45 (47%) of the fetuses were in lateral or ventral position, and 28 (30%) of the fetuses were malformed (mainly torticollis and head scoliosis). All 98 c...
Ducharme NG, Burton JH, van Dreumel AA, Horney FD, Baird JD, Arighi M.The nutritional implications and adaptive processes resulting from resection of 75% of the length of the large colon in ponies were investigated. Ten ponies in good physical condition were divided into two groups: six in the experimental group and four in the control group. During the sixth postoperative month, two digestibility studies were conducted, and phosphate fractional renal excretion and serum biochemical profiles were determined in both groups. The ponies (N = 10) were euthanized six months postoperatively, and gross and histopathological examinations were performed. Results of the s...
Johnstone IB, Petersen D, Crane S.Plasma Antithrombin III (ATIII) activity was quantitated in 24 clinically normal Standardbred/Thoroughbred horses using a clotting time technique. ATIII activity ranged from 80 to 106% of the pooled reference standard plasma, with a mean of 94%. Horses presenting with impaction or spasmotic colic (n=17) had normal plasma ATIII activity, while 15 horses presenting with acute diarrhea/colitis had significantly lower plasma ATIII activity with a mean of only 74% of the reference plasma. Seven horses presenting with liver disease had significantly higher plasma ATIII activity with a range of 127 t...
Murphy CJ, Howland HC.One factor peculiar to the practice of comparative ophthalmoscopy is the very large variation in ocular size of the animals examined, a factor which is ignored in current textbook treatments of the subject. We have computed values of lateral magnification, axial magnification, angular field of view and linear field of view for 19 species of terrestrial vertebrates. The dimensional value of a 1 diopter change in direct ophthalmoscopic focus was also determined. The anterior focal length of the eye in air and the vitreal refractive index were the intrinsic optical parameters of the animal's eye ...
Hoffman LS, Adams TE, Evans JW.Blood samples were obtained from 5 mixed-breed, long-term castrated geldings during five 24-h periods between May 1984 and April 1985. Blood samples were collected, beginning at 09:00 h, at 15-min intervals for 8 h and hourly for the remaining 16 h. Plasma concentrations of LH and FSH were determined by RIA. Seasonal changes in hormone concentrations and frequency and amplitude of secretory pulses were evaluated. No diurnal variation in either LH or FSH secretion was observed: however, marked circhoral fluctuations in LH and FSH secretion were noted. Mean LH and FSH concentrations in these lon...
Higgins AJ, Lees P, Sedgwick AD, Buick AR, Churchus R.In a two-part cross-over experiment in six ponies, an acute inflammatory reaction was generated by injecting carrageenin solution into subcutaneously-implanted tissue-cages lined with fibrovascular granulation tissue. In each part of the cross-over, half of the ponies received a novel phenylpyrazoline anti-inflammatory agent (BW540C) orally and half received a placebo treatment. BW540C inhibited platelet cyclo-oxygenase for 24 h but the reductions in exudate eicosanoid concentrations were less pronounced. A significant suppression in the rise of surface skin temperature in BW540C-treated ponie...
Alexander SL, Irvine CH, Turner JE.FSH was measured in the pituitary, and in pituitary venous and jugular blood collected at frequent intervals from mares in various reproductive states, using 3 validated and highly specific radioimmunoassay systems based on different antibodies, 'o', 'h' and 'e'. In the pituitary, 4 forms of FSH were found which differed in isoelectric point and relative potency in the 3 assays. In jugular blood, mean FSH concentrations and short-term patterns depended on the assay used and the reproductive state of the mare. In pituitary venous blood, although FSH concentrations were greatly elevated above ju...
Ziemer EL, Whitlock RH, Palmer JE, Spencer PA.The clinical and hematologic variables of 10 ponies with experimentally induced equine ehrlichial colitis (EEC; syn: Potomac horse fever) were studied for a 30-day period (6 ponies) or until death (4 ponies). The earliest clinical sign indicative of EEC was fever (rectal temperature exceeding 39 C). All ponies became depressed (CNS) at various times during the disease, and 90% of the ponies developed diarrhea between 9 and 15 days after infection was induced. The most significant hematologic change was an increase in plasma protein concentration after the onset of fever (P less than 0.05). The...
Kiryu K, Nakamura T, Kaneko M, Oikawa M, Yoshihara T.Twenty thoroughbred race horses were selected for postmortem cardiopathological study of sudden cardiac death; ten of the twenty horses died suddenly. In order to define accurately the morphological changes observed in these ten hearts, ten other thoroughbred race horses considered to have normal hearts were selected as a control group and studied by postmortem coronary angiography. Of the ten horses that died suddenly, eight were witnessed to have died either during or shortly after training or racing. The death was instantaneous except in one horse, which showed ventricular tachycardia and d...
McEntee M, Summers BA, de Lahunta A, Cummings J.A 3-year-old horse presented with intermittent generalized seizures of 2-month duration. During interictal periods, the horse appeared normal and a cause for the seizures could not be identified. Necropsy revealed opacity of the leptomeninges, covering most of one cerebral hemisphere along with thinning and collapse of the cortex in the ipsilateral pyriform lobe. Histopathology demonstrated leptomeningeal vascular proliferation and meningothelial hyperplasia. Prominent tortuous vessels of the gyri and sulci extended into some regions of the subjacent cortex, where there was neuronal loss, ecto...
Coombs SL, Webbon PM.The rate of movement up the mucociliary escalator of Technetium99m tagged to macroaggregated albumin was measured in 7 normal horses and 8 with respiratory disease. The activity at 2 sites in the neck, separated by 12-15 cm, was measured using a hand held scintillation counter and rate meter. In normal horses the Technetium complex moved as a bolus up the neck with a mean rate of 1.58 cm/min. In the horses with respiratory disease the Technetium complex was less likely to move as a discrete bolus and in three horses it was not possible to measure the transport rate. The remainder had a mean tr...
Pellegrini A, Hägeli G, von Fellenberg R.1. Trypsin digestion of perchloric acid precipitated horse plasma yielded polypeptides with inhibitory properties for trypsin, chymotrypsin and, to a small extent, kallikrein. 2. The Mr of the inhibitory polypeptides were 73,000 and 24,000. 3. The number, enzyme specificity and Mr of the inhibitory polypeptides differed from the values known for the human being. 4. The inhibitory polypeptides were purified by affinity chromatography on Sepharose-trypsin and by gel filtration through Sephadex G-75. 5. Protease inhibitory polypeptides were generated in the same manner by chymotrypsin, elastase, ...
Rose PL, Hightower D, Auer JA, Hulse D, Schenk RK.In the present study, radionuclide scintigraphy and radiography were used to evaluate the rate and degree of healing that occurred in surgically created subchondral bone defects in horses. Following radionuclide scintigraphy and radiography the horses were killed, and histomorphometric analysis was performed on the defect sites. The histomorphometric results were compared to the radionuclide scintigraphic and radiographic results to determine which noninvasive technique provided the most accurate information concerning healing of the bone defects. It was concluded that radionuclide scintigraph...
Manning AW, Rajkumar K, Bristol F, Flood PF, Murphy BD.The variation in the quantity of circulating chorionic gonadotrophin (CG) and its follicle-stimulating hormone (FSH) and luteinizing hormone (LH) activity in rodent bioassay systems was investigated. A portion of the variability in total CG could be attributed to the stallion that sired the pregnancy and it was possible to select sires and mares to increase CG production. It was further demonstrated that FSH activity per unit of CG was greater at Days 71 and 104 of gestation than at Day 39. LH activity per unit of CG varied with the sire, but no effect of day of gestation could be shown. It wa...
Miller SK.1. Results of laboratory experiments which compared horse and human serum butyrylcholinesterase (EC 3.1.1.8) with respect to their acid inactivation and ammonium sulfate protection show: 2. Horse serum butyrylcholinesterase is more resistant to inactivation at pH 3.0 than human serum butyrylcholinesterase. 3. The loss of activity at pH 3.0 for both horse and human butyrylcholinesterase does not follow first order kinetics. 4. Both human and horse serum butyrylcholinesterase are protected from pH 3.0 inactivation by ammonium sulfate concentrations up to 33% saturation (1.37 M).
Kraft W, Gawlik A, Grabner A, Dämmer EM.In 183 cases of chronic obstructive pulmonary disease (COB, COPD) grades I to IV horses were treated with bronchospasmolytic and secretolytic drugs, corticosteroids, mass infusions of physiological saline solution and with combinations of these treatments. The long-term effects of the above described methods of treatment based on questionnaire with the owners will be discussed. The results are to be considered successful if there is no evidence of irreversible alterations of the lungs, and if the horse is kept away from dust as much as possible.
Firth EC, Greydanus Y.The talus and proximal and distal epiphysis of the humerus, radius, femur, tibia and distal metacarpus of 20 foals aged 0 to 150 days were obtained at necropsy and sawn sagittally into slabs 4 to 8 mm thick. The thickness of the cartilage (articular cartilage and unossified epiphyseal cartilage) was measured in three to five places in each slab, using a sliding calliper. In most epiphyses, the site, or sites, of thickest cartilage was constant in all foals examined. The difference between thickest and thinnest cartilage within one epiphysis was greatest in distal femora and least in distal met...
Brown CM, Sonea I, Nachreiner RF, Obradovich JE.Using commercially available diagnostic reagents, serum immunoreactive gastrin activity was measured in five normal horses that were starved of food and water for 24 hours. Blood samples were taken every 15 minutes for two hours. The horses were then fed a pelleted diet for 15 minutes and samples were taken every 15 minutes for a further two hours. Three further samples were taken at hourly intervals. The total sampling period was seven hours. Basal immunoreactive gastrin activity was lower than that reported in other mammals, ranging from a mean of 7.0 pg/ml to 13.8 pg/ml. At 30, 60 and 75 mi...
Gossett KA, Cleghorn B, Adams R, Church GE, McCoy DJ, Carakostas MC, Flory W.Increased anion gap (AG) was due, in part, to L-lactic acidosis in 14 of 14 horses with intestinal disorders. In a few horses, increased whole blood concentrations of D-lactate made a minor contribution to the AG. However, the increase in AG was often greater than the sum of the increases in these 2 acid anions. This unexplained increase was not a result of increases in whole blood pyruvate, 3-hydroxybutyrate, or acetoacetate concentrations or serum albumin or phosphate concentrations. Identification of other anions causing increased AG could lead to better understanding, diagnosis, and treatm...
Mayr A.Among all infectious diseases affecting horses, respiratory disease pose the greatest threat to horses kept in stables, horses used for breeding and race horses. Here a distinction should be made between the so-called monocausal infectious diseases (so-called Henle-Koch postulates) and multicausal infectious diseases which are the result of the synergistic interaction of different processes, that alone do not lead to disease. There is no clearcut distinction between the two groups. The most important monocausal respiratory infections of horses are caused by equine influenza virus (subtypes 1 a...
Engelking LR, Lofstedt J, Blyden GT, Greenblatt DJ.The following studies were designed to evaluate plasma elimination kinetics of intravenously administered antipyrine, acetaminophen and lidocaine among 9 healthy adult horses and 9 healthy drug-free humans (3 each per drug group), in order to compare potential species differences in drug-metabolizing ability. Acetaminophen is largely biotransformed in humans by hepatic glucuronide and sulfate conjugation, whereas both antipyrine and lidocaine are oxidized by hepatic microsomal mixed-function oxidases. Thus, plasma clearances of these drugs are thought to reflect differences in hepatic oxidativ...
Liggett AD, Weiss R, Blue JL.Myospherulosis was diagnosed in a mature pony. Several parent bodies containing many spherules were observed microscopically in biopsy material from an area of cellulitis. The spherules are altered red blood cells that form as the result of prolonged contact with necrotic fat or petrolatum-based ointments. These structures must be differentiated from fungal elements. The recommended treatment is surgical excision.
Costa PWL, Oliveira CSM, Bezerra RA, Alvares FBV, Formiga VHAS, Martins MRDD, Feitosa TF, Vilela VLR.The aim of this study was to describe the prevalence of anti- and anti- antibodies in equids that carry out traction work in Northeastern Brazil, and to establish the potential risk factors associated with seropositivity for these agents. Blood samples were collected from 322 traction equids (horses, donkeys and mules) in urban areas of 16 municipalities in the State of Paraíba, Brazil. The samples were sent for serological diagnosis using the Immunofluorescence Antibody Test (IFAT). Epidemiological questionnaires were given to the owners to assess the possible risk factors associated with in...
Merkt H, Klug E, Krause D, Bader H.Stallion semen frozen by the pellet method showed no significant loss of sperm motility and fertility over long periods of storage in liquid nitrogen. Eighteen of thirty mares conceived after insemination with semen recovered in nine ejaculates from seven stallions and stored for 18 months to 7 years.
The locomotor pattern alterations produced after the administration of a sublingual detomidine gel was measured by an accelerometric method in horses. Using a randomized two-way crossover design, all animals (n = 6) randomly received either detomidine gel or a placebo administered sublingually. A triaxial accelerometric device was used for gait assessment 15 minutes before (baseline) and every 10 minutes after each treatment for a period of 180 minutes. Eight different parameters were calculated, including speed, stride frequency, stride length, regularity, dorsoventral, propulsion, mediolater...
Lü Y, Wang H, Yang J.A direct high-performance gel permeation chromatographic (HPGPC) method for the determination of immunoglobulin G in mare colostrum was established. HPGPC separation was performed on a TOSOH TSK-G4000PW(XL) column (300 mm x 7.8 mm, 5 microm) with 0.05 mol/L phosphate buffer solution (pH 6.9) as the mobile phase at a flow rate of 0.8 mL/min, and the column temperature was maintained at 25 degrees C. The injection volume was 20 microL. At the detection wavelength of 280 nm, the linear range was from 0.2 to 3.0 g/L (r2 = 0.999 5) with a detection limit of 0.08 mg/L (S/N = 10). The recovery was 97...
Lamar CH, Masty J, Adams SB, Tacker WA.Myoelectrical and myomechanical activities of the distal portion of the jejunum and pelvic flexure were studied in 7 ponies, using permanently implanted monopolar and bipolar stainless steel electrodes. Dental acrylic embedded recording electrodes were surgically sutured to the serosal surface of the distal portion of the jejunum and pelvic flexure. Myoelectrically, regular spike bursts and irregular spike bursts were observed in the jejunum. Short spike bursts and long spike bursts were recorded and associated with spike potentials, using impedance recording techniques. Electrical and mechani...
Nyman S, Kokkonen UM, Dahlborn K.To investigate effects of hydration status and exercise intensity on plasma atrial natriuretic peptide (ANP) concentration in exercising horses. Methods: 4 trained Standardbreds. Methods: Horses performed a 40-minute exercise test at 65 to 70% maximal heart rate (HRmax; no incline) and a 12-minute test at approximately 90% HRmax (3.5 degrees incline). The 40-minute test was performed with ad libitum access to drinking water (normohydration), after water had been withheld for 24 hours (dehydration), and 30 minutes after 12 L of water at body temperature had been given via nasogastric tube (hype...
Cuervo-Arango J, Aguilar JJ, Vettorazzi ML, Martínez-Boví R.The present study characterizes the relationship between the levels of eCG, ovarian morphology, resumption of cyclicity, and fertility in postaborted embryo transfer recipient mares. A total of 32 pregnant recipient mares carrying a male fetus were aborted at approximately 65 days of gestation by single transcervical administration of cloprostenol. In addition, 25 gestation age-matched mares were used as nonaborted controls. The concentration of progesterone, but not of eCG, differed significantly between controls and aborted mares 48 hours after abortion. Of treated mares, 84.4% (27 of 32) ex...
Short CR, Sams RA, Soma LR, Tobin T.The primary reason for developing the ARCI Uniform Classification of Foreign Substances was to give stewards and other racing regulators guidelines to assist them in understanding the relative performance effects and general offensiveness to the Rules of Racing of various drugs and medications. As such, these guidelines have been very useful in the world of racing regulation--officially or unofficially--because this classification system, for the first time, places a relative number on the inappropriateness of any one of more than 750 agents appearing in forensic samples taken from racing hors...
Olsen SN, Schumann T, Pedersen A, Eriksen L.It was demonstrated in the present study that a simple Baermann technique using disposable materials, was successful in detecting living, motile cyathostome larvae in the faeces of horses.
Anderson SL, Blackford JT, Kelmer SG.This study describes the outcome and complications in horses that had a closed, one-stage, stapled, functional, end-to-end (COSFE) jejuno-ileal anastomosis (JIA) following resection of compromised small intestine. Medical records were reviewed to identify all horses that had a COSFE JIA performed during exploratory laparotomy and to determine post-operative complications and final outcome. All 5 horses that were identified had successful COSFE JIA with resection of various amounts of distal jejunum and proximal ileum. Post-operative ileus occurred in 1 of the 5 horses. All horses survived at l...
Pruß D, Yang H, Luo X, Liu D, Hegermann J, Wolkers WF, Sieme H, Oldenhof H.Stallion sperm is typically cryopreserved using low cooling rates and low concentrations of cryoprotective agents (CPAs). The inevitable water-to-ice phase transition during cryopreservation is damaging and can be prevented using vitrification. Vitrification requires high cooling rates and high CPA concentrations. In this study, the feasibility of stallion sperm vitrification was investigated. A dual-syringe pump system was used to mix sperm equilibrated in a solution with a low concentration of CPAs, with a solution containing a high CPA concentration, and to generate droplets of a defined si...
Breit S, König HE.20 extremities of horses were used to investigate the synovial membrane of the distal interphalangeal joint and the navicular bursa. From each extremity five specimens were taken from the distal interphalangeal joint capsule, two further from the navicular bursa. Synovial villi were found near the articular cartilage as well as everywhere where the joint capsule did not form a tight periostal cover or was not connected with ligaments or tendons. Some lay between the articular surfaces of the phalanx media and phalanx distalis. Besides synovial villi and synovial folds "trabecular-like" cords o...