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.
Johnson GC, Kohn CW, Johnson CW, Garry F, Scott D, Martin S.Ultrastructural examination of a mechanobullous disease of probable hereditary nature in Belgian foals, confirmed light microscopic findings that separation of the dermo-epidermal junction occurred through the lamina lucida of the basement membrane, leaving the intact lamina densa adherent to the dermis and the plasmalemma of the basal epithelial cells intact. The location of the cleft and the presence of small hemidesmosomes in adjacent intact skin are additional characteristics which make this condition similar to junctional epidermolysis bullosa of man.
Wilson WD, Spensley MS, Baggot JD, Hietala SK.The pharmacokinetics and estimated bioavailability of amoxicillin were determined after IV, intragastric, and IM administration to healthy mares. After IV administration of sodium amoxicillin (10 mg/kg of body weight), the disposition of the drug was best described by a 2-compartment open model. A rapid distribution phase was followed by a rapid elimination phase, with a mean +/- SD half-life of 39.4 +/- 3.57 minutes. The mean volume of distribution was 325 +/- 68.2 ml/kg, and the mean body clearance was 5.68 +/- 0.80 ml/min.kg. It was concluded that frequent IV administration of sodium amoxic...
Wood TC, White KL, Thompson DL, Garza F.This experiment was designed (1) to determine if H-Y antigen is expressed on the cell surface of pre-implantation equine blastocyst stage embryos, (2) if so, to identify differences in expression on inner cell mass (ICM) verses trophectoderm cells and (3) to evaluate whether the detection of this glycoprotein would aid in the identification of equine embryonic sex. A total of 33 blastocyst stage horse embryos were collected 6-7 days post-ovulation by trans-cervical flush and were immediately evaluated for the presence of H-Y antigen. Additionally, 17 embryos, collected at similar stages and cu...
Eguchi M, Kuniyasu C, Kishima M.The passive hemagglutination (PHA) test was improved to enable the detection of antibodies to Taylorella (Haemophilus) equigenitalis in the sera of mares. Horse red blood cells (RBC) fixed with glutaraldehyde were compared with similarly treated RBC of a cow, pig and sheep for the PHA test. The horse RBC were superior to those of the other animals tested in detecting mares affected with contagious equine metritis (CEM). A PHA test using these cells as indicator and an antigen prepared from T. equigenitalis by sonication following treatment with hyaluronidase was the most satisfactory in terms ...
Godovac-Zimmermann J, Conti A, Napolitano L.The complete primary structure of donkey lysozyme has been established by pulsed liquid-phase sequencing of tryptic and chymotryptic peptides isolated by RP-HPLC. The positions of the Cys residues were identified by labeling the Cys residues with DABIA-reagent. Donkey lysozyme is a c-type lysozyme which is 129 amino acids long. It exhibits 50% homology to the human protein. We observe the full Ca(II) binding site suggested for the homologous alpha-lactalbumines. Although horse lysozyme has been reported to contain asparagine in position 61, which was in conflict with the three-dimensional stru...
Scott TW, Olson JG, All BP, Gibbs EP.Sensitivity and specificity of an antigen-capture ELISA vs virus isolation in cell culture were evaluated for the detection of eastern equine encephalomyelitis (EEE) virus in the brain tissue of naturally infected equids. Brain specimens from 16 equids with neurologic disease were examined by ELISA and by inoculation onto baby hamster kidney cell cultures. Of 10 brain samples from which virus was isolated in the cell culture bioassay, all were correctly identified as containing EEE virus antigen by ELISA. None of the remaining 6 specimens, without detectable infectious EEE virus, contained det...
De Auer , Ng JC, Seawright AA.The copper and zinc concentrations in the blood of stabled thoroughbred horses and in Australian Stock Horses mares at pasture, either late pregnant or lactating were determined by an atomic absorption spectroscopic method. The plasma concentration of the trace elements in these apparently normal horses were generally below the "normal" range. The plasma copper, caeruloplasmin copper, whole blood copper and plasma zinc concentrations in the stabled thoroughbreds were 0.76 +/- 0.19 micrograms/ml (n = 82), 0.56 +/- 0.14 micrograms/ml (n = 83), 0.75 +/- 0.18 micrograms/ml (n = 82) and 0.47 +/- 0....
Thompson KN, Jackson SG, Baker JP.Effects of high dietary levels of energy, protein and Ca and deficient levels of Ca on skeletal growth and development in the equine were studied in two experiments. The weanlings were fed grain-based diets. In Exp. 1, Group 1 (Ctl) received all nutrients at NRC recommended levels for growth; Group 2 (HE) received 150% of their digestible energy (DE) requirement; Group 3 (LC) received 150% of DE and 35% of Ca requirements. In Exp. 2, Group 1 (Ctl) again received all nutrients at NRC recommended levels for growth; Group 2 (HEP) received 150% of DE and 275% of CP requirements; Group 3 (HEPC) rec...
Dill SG, Gleed R, Matthews NS, Erb HN, Miller TK.The acupuncture point Governing Vessel (GV-26) is used commonly in the Orient to treat shock in human beings and other species. The cardiovascular effects of stimulation of GV-26 were studied in healthy ponies during 2 episodes of halothane anesthesia. During one anesthetic episode, electrical stimulation (electrostimulation) of GV-26 was performed, and during the other anesthetic episode, heat stimulation (moxibustion) of GV-26 was performed. The order of the stimulations was random. A nonacupuncture point was selected for comparable control stimulation during each experiment. Control and acu...
Blancquaert AM, Colgan SP, Bruyninckx WJ.Although equine neutrophils did not respond towards formylated methionyl peptides, Streptococcus faecalis culture supernatant caused an in vitro stimulation of equine neutrophil motility when measured by an under-agarose assay. The migration of neutrophils towards the culture supernatant increased sigmoidally with the logarithmic concentration of the culture supernatant in the chemoattractant wells. The streptococcal culture supernatant was chemokinetic because it stimulated the random motility of the phagocytes. Because granulocytes migrated further towards the supernatant than could be expla...
Dutta SK, Penney BE, Myrup AC, Robl MG, Rice RM.Fifty-five horses were inoculated IV and/or SC with materials containing Ehrlichia risticii, ie, infected whole blood, buffy coat cells, or cell culture, to study clinical and hematologic features of equine monocytic ehrlichiosis (Potomac horse fever). Major clinical and hematologic features of induced E risticii infection were biphasic increase in rectal temperature with peak increases of 38.9 C and 39.3 C on postinoculation days (PID) 5 and 12, respectively; depression; anorexia; decreased WBC count (maximal decrease of 47% on PID 12); and diarrhea from PID 14 to PID 18. Increased WBC count ...
Frazer GS, Rossol TJ, Threlfall WR, Weisbrode SE.Endometrial fibrosis is a major cause of infertility in broodmares. Because of the proven anti-inflammatory effects of dimethyl sulfoxide (DMSO) and its influence on collagen, the effect of DMSO on the endometrium was investigated in mares. Solutions of DMSO (25%, 50%, or 75%) were infused into the uterus of clinically normal mares. Examination of serially obtained biopsy specimens revealed epithelial ulceration and stromal inflammation that were proportional to the DMSO concentration infused, but vasodilatation was not observed. In all mares, the endometrium had returned to normal by day 21 a...
Broström H, Fahlbrink E, Dubath ML, Lazary S.The distribution of equine leucocyte antigens (ELA) in Swedish Halfbreds affected by sarcoid tumors was determined and compared with that of control horses of the same breed. ELA-haplotype A3W13 appeared more frequently in affected horses, resulting in a chi 2 value of 4.45 (P = 0.034) for A3 and 9.05 (P = 0.0026) for W13, respectively. The relative risk factor (RR) could be estimated to 2.13 and 3.00 for A3 and W13, respectively. The etiology fraction (EF) was calculated to 28% and 37% for A3 and W13, respectively. Thus, in the population of Swedish Halfbreds approximately 40% (at least) of t...
Swanson SP, Helaszek C, Buck WB, Rood HD, Haschek WM.The role of faecal and intestinal microflora on the metabolism of trichothecene mycotoxins was examined in this study. Suspensions of microflora obtained from the faeces of horses, cattle, dogs, rats, swine and chickens were incubated anaerobically with the trichothecene mycotoxin, diacetoxyscirpenol (DAS). Micro-organisms from rats, cattle and swine completely biotransformed DAS, primarily to the deacylated deepoxidation products, deepoxy monoacetoxyscirpenol (DE MAS) and deepoxy scirpentriol (DE SCP). By contrast, faecal microflora from chickens, horses and dogs failed to reduce the epoxide ...
Shappell KK, Derksen FJ, Stick JA, Robinson NE.Effects of ventriculectomy and prosthetic laryngoplasty on upper airway flow mechanics and blood gas tensions in exercising horses with induced left laryngeal hemiplegia were assessed. Five adult horses were trained to stand, trot (4.5 m/s), and gallop (7.2 m/s) on a treadmill (6.38 degrees incline). Inspiratory and expiratory airflows (VImax, VEmax, respectively) were measured using a 15.2-cm diameter pneumotachograph in a face mask. Inspiratory and expiratory transupper airway pressures (PuI, PuE, respectively) were determined as pressure differences between barometric pressure and lateral t...
Darien BJ, Belknap J, Nietfeld J.Two horses with cerebrospinal nematodiasis (Micronema deletrix) had signs similar to those of other neurologic diseases resulting from parasitic (fly larvae, protozoa, or other helminths) migration through the central nervous system (CNS). In one horse (horse 1), a 13-year-old Paso Fino stallion, the cerebrospinal fluid (CSF) was slightly xanthochromic (1+), with a pleocytosis (25 nucleated cells/microliter) and a normal protein level (69 mg/dl). A CSF differential cell count showed 15% neutrophils, 56% lymphocytes, 22% macrophages, 5% eosinophils, and 2% basophils. In the other horse (horse 2...
Morse CC, Richardson DW.An unusually large, pedunculated (20 cm long) mass arising the gastric pylorus which produced complete obstruction of the proximal duodenum and severe gastric distension was found in a 13-year old castrated male Arabian horse. The histological diagnosis was gastric hyperplastic polyp, which has not been reported previously in the horse. The clinico-pathological findings in this horse are compared with hyperplastic (inflammatory) gastric polyps of man.
Bertone AL, Jones RL, McIlwraith CW.The tarsocrural joints of 11 horses were inoculated with 1.2 to 2.16 x 10(6) viable Staphylococcus aureus organisms susceptible to a trimethoprim-sulfadiazine (TMP-SDZ) combination with minimal inhibitory concentration (MIC) of 0.25 micrograms of TMP/ml and 4.75 micrograms of SDZ/ml. Antimicrobial treatment consisted of oral administration of a TMP-SDZ combination--30 mg/kg of body weight given once daily (group-1 horses) or 60 mg/kg given as 30 mg/kg every 12 hours (group-2 horses). Paired serum and synovial fluid samples were obtained before intra-articular inoculation with the S aureus, aft...
Godsey MS, Amoo F, Yuill TM, Defoliart GR.A serologic survey and experimental virus transmission studies were done to assess the role of domestic animals as amplifier hosts of La Crosse (LACV) and Jamestown Canyon (JCV) viruses. Serum from 319 cows, 88 dogs, 122 equines, 47 swine, 10 goats, and 4 cats were tested for neutralizing antibody to LACV, JCV, trivittatus (TVTV), and snowshoe hare (SSHV) viruses. Antibody prevalences of LACV, TVTV, and SSHV were less than 10% in all species. Antibody to JCV was detected in all species except cats. Prevalence ranged from 10% in goats and swine to 29% in dogs. No age-associated trends in JCV pr...
Bertoti DB.The purpose of this study was to measure postural changes in children with spastic cerebral palsy after participation in a therapeutic horseback riding program. Eleven children with moderate to severe spastic cerebral palsy, aged 2 years 4 months to 9 years 6 months, were selected for this study and underwent postural assessments according to a repeated-measures design. Assessment of posture was performed by a panel of three pediatric physical therapists, using a postural assessment scale designed by the author. A composite score for each test interval was calculated for each child, and a medi...
Manohar M.The present study was carried out 1) to compare blood flow in the costal and crural regions of the equine diaphragm during quiet breathing at rest and during graded exercise and 2) to determine the fraction of cardiac output needed to perfuse the diaphragm during near-maximal exercise. By the use of radionuclide-labeled 15-micron-diam microspheres injected into the left atrium, diaphragmatic and intercostal muscle blood flow was studied in 10 healthy ponies at rest and during three levels of exercise (moderate: 12 mph, heavy: 15 mph, and near-maximal: 19-20 mph) performed on a treadmill. At re...
Eustachiewicz R, Flieger S, Boratyński Z, Sławomirski J.The material for the study was taken from 2 spinal cords of sexually mature horses. Preparations obtained from this material were stained according to Nissl and with the use of cresyl violet. The nucleus dorsalis of the horse extends from the 8th cervical neuromere to the 3rd lumbar neuromere of the spinal cord. The cells which form this nucleus lie in the grey matter of the spinal cord, dorsolaterally of the central canal. The nucleus dorsalis is made out of large and medium-size round and oval cells. The characteristic feature of the structure and configuration of this nucleus in the horse i...
Harrison LJ, May SA, Richardson JD, Mills G, Dixon P.Four horses with an incomplete fracture of a hindlimb longbone were examined. In two, the tibia had been fractured by external trauma. In the other two horses proximal metatarsal 3 had fractured during normal activity. The diagnoses were made radiographically and the horses were treated conservatively by box rest. The fractures healed satisfactorily and the horses became sound.
Colahan P, Lindsey E, Nunier C.The pressure exerted on a flat level surface by recently trimmed, unshod hoofs of the front limbs of 23 sound, adult horses was measured using pressure-sensitive film and a specially built cassette. The horses were tranquilized and stood with one foot on the 2.9-cm-thick cassette and the other on a block of equal height. The hoofs were observed for motion during the measurement, and the developed film was examined for improper alignment of the film or slipping of the hoof. The center of pressure was located using the method of weighted proportions of Barrey. This static measurement system with...
Riber C, Cuesta I, Muñoz A, Gata J, Trigo P, Castejón FM.Fatigue during endurance rides might induce changes in gait pattern that could be difficult to distinguish from subtle lameness. Objective: To assess changes in gait pattern en route, in fore(FL) and hindlimbs (HL) and establish differences between excellent (EP) and good performers (GP). Methods: Seventy-five sound and fit horses that completed endurance rides of 80 km were filmed at trot in the vet-gates (VGs) prior to competitions (VGO), and at 29 km (VG1), 59 km (VG2) and 80 km (VG3). Mean gait velocity (V), stride length (SL), duration (SD) and frequency (SF) were measured. Also, stance (...
Ball MA, Weldon AD.A 5-year-old Appaloosa gelding was presented with a history of intermittent multiple joint swelling, weight loss, and anemia. Physical examination and clinical pathology revealed a grade IV/VI holodiastolic murmur, louder on the left, and a marked hyperproteinemia. Echocardiography of the heart demonstrated a large vegetative lesion on one of the aortic valve cusps. Blood cultures did not elucidate the causative organism, and the disease was refractory to empiric antibiotic therapy. The horse was euthanized after approximately 2 months of therapy.
Friedman R.The value of providing equine reproductive services in ambulatory setting is well established. Ambulatory practice has been, and will most likely continue to be, the primary provider of equine reproductive veterinary services. The limitations for performing various reproductive procedures in an ambulatory setting are those imposed by the amount of equipment and supplies that must be brought to the patient, as well as those imposed when procedures require additional assistance. This is analogous to human medical care: the ambulance cannot substitute for a hospital but it can certainly provide s...
Parker RA, Bladon BM, Parkin TD, Fraser BS.Increased radio-isotope uptake (IRU) in the subchondral bone of the plantaro-lateral condyle of the third metatarsus (MTIII) is a commonly reported scintigraphic finding and potential cause of lameness in UK Thoroughbred racehorses in training and has not been fully documented. Objective: To characterise lameness attributable to IRU of the subchondral bone of MTIII, compare the scintigraphic findings of these horses with a normal population and evaluate the use of scintigraphy as an indicator of prognosis. Objective: IRU will be in significantly higher in horses with subchondral bone injury an...
Hillidge CJ, Lees P.The neuroleptanalgesic drug combination of
etorphine and acepromazine (Large Animal
Immobilon; Reckitt & Colman Ltd.) was
administered i.v. at the recommended dose rate
(24 ,ug/kg etorphine and 100 pg/kg acepromazine)
to twelve Welsh Mountain ponies of 185 to 336 kg
bodyweight. Cardiovascular measurements were
made before and at pre-determined times up to
30 min after the injection. The etorphine
antagonist, diprenorphine (Revivon; Reckitt &
Colman Ltd.), was then injected i.v. (30,ug/kg)
and further measurements were obtained.
Pronounced increases in heart rate, moderate
increase...
Logas D, Kunkle G, Calderwood-Mays M, Frank L.An 8-year-old gelding, with a 1-year history of intense pruritus only after exercise, was diagnosed as having cholinergic pruritus. Provocative testing, using exercise and hot-water baths to increase core body temperature, assisted in the diagnosis. Cholinergic pruritus in human beings is a variant of the more common syndrome, cholinergic urticaria, which is characterized by intense pruritus and pinpoint urticaria. With cholinergic pruritus, intense itching results without urticaria. Specific diagnostic laboratory tests have not been developed.
Montgomery K, Ortved K, DeVries J, Hackett R, Kern T, Irby N, Ducharme N.A 7-year-old Connemara stallion was presented with a 4 month history of blepharospasm, recurrent corneal ulcerations, mucopurulent ocular discharge, and keratoconjunctivitis sicca (KCS) in both eyes unresponsive to medical therapy. Ophthalmic examination revealed lackluster corneas, axial corneal scarring and pigmentation with associated neovascularization, and absolute KCS in both eyes. Computed tomography scan and endoscopic evaluation of the upper airway and guttural pouches revealed no structural abnormalities to indicate neurogenic KCS. The stallion was diagnosed with immune-mediated dacr...
Brown MP, Gronwall RR, Martinez DS, Beal C.Six healthy pony foals, from 2 to 11 days of age, were given a single IM injection of amikacin sulfate (250 mg/ml) at a dosage rate of 7 mg/kg of body weight. Serum amikacin concentrations were measured serially over a 24-hour period. The mean peak serum concentration was 14.7 micrograms/ml at 0.5 hour. The elimination rate constant for amikacin was 0.24/hour, the elimination half-life was 3.0 hours, and the apparent volume of distribution was 0.58 L/kg.
Grzeskowiak RM, Barrett EJ, Rodgerson DH.An 11-year-old Thoroughbred mare with colic unresponsive to medical treatment underwent exploratory laparotomy. During surgery the cecum was found entrapped within the epiploic foramen from left to right. The entrapped cecum was reduced through the foramen by gentle traction. After reduction of the cecum, rupture of the portal vein was detected. Loss of a large amount of blood prompted euthanasia during surgery. Une jument Thoroughbred âgée de 11 ans atteinte de coliques ne répondant pas au traitement médical a subi une laparatomie exploratoire. Durant la chirurgie, le cæcum a été trou...
Lewis DD.A classification scheme for penetrating joint injuries is presented. Diagnostic techniques and treatment recommendations for managing penetrating joint injuries in small animals are described. Techniques used in human and equine patients are discussed for comparison.
Gift LJ, DeBowes RM.Nonhealing wounds can present a frustrating clinical challenge to the veterinary practitioner. In many cases, healing is delayed by the presence of a foreign body or sequestrum; a review of wounds complicated by the presence of osseous sequestration and penetrating foreign bodies is presented. The typical signs include delayed wound healing and the presence of serous to exudative drainage, which may vary from intermittent to continuous. The use of radiographic or sonographic imaging modalities is often of value in reaching a diagnosis. Removal of the sequestra or foreign body is generally cura...
Townsend WM, Langohr IM, Mouney MC, Moore GE.Based on the current literature, neither medical, surgical nor combination therapy adequately controls equine glaucoma for many horses. Aqueous shunts have been useful in other species to control glaucoma. Objective: To determine whether aqueous shunts in normal equine eyes significantly reduce intraocular pressure (IOP) without causing vision threatening complications. Methods: Prospective experimental trial. Methods: Aqueous shunts were placed in 7 normal eyes of 4 horses. The shunts were placed dorsotemporally. Examinations were initially performed daily for 7 days and after that every 3 da...
Gaynor JS, Bednarski RM, Muir WW.The effect of xylazine on the arrhythmogenic dose of epinephrine (ADE) was studied in 9 horses. Anesthesia was induced by administration of guaifenesin (50 mg/kg of body weight, IV) followed by thiamylal (4 to 6 mg/kg, IV) and was maintained at 1 minimal alveolar concentration (MAC) of halothane (0.89%). Base apex ECG and facial artery pressure were recorded. Epinephrine was infused in a sequence of arithmetically spaced increasing rates (initial rate 0.25 micrograms/kg/min) for a maximum of 10 minutes. The ADE was defined as the lowest epinephrine infusion rate to the nearest 0.25 micrograms/...
Thompson DL, Reville-Moroz SI, Derrick DJ, Walker MP.Sixteen intact cyclic mares were treated on the fourth day of estrus and then every other day for a total of six injections with 1) testosterone propionate, 2) dihydrotestosterone (DHT) benzoate, 3) estradiol (E2) benzoate or 4) safflower oil. Mares were given gonadotropin releasing hormone (GnRH) on Day 3 of estrus (pretreatment) and again 24 h after the last steroid or oil injection. Treatment with testosterone propionate resulted in a greater (P less than 0.05) follicle-stimulating hormone (FSH) response to the second injection of GnRH compared with all other treatments. Treatment with DHT ...