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.
Scott EA, Chaffee A, Eyster GE, Kneller SK.Two foals with a history of normalcy at birth developed a lack of exercise tolerance and weakness in the first few days of life. Weakness, inability to rise, and reluctance to suckle were common complaints. Physical examination of both foals revealed a cardiovascular abnormality, with a loud systolic murmur audible over both thoracic walls. Additional diagnostic techniques were blood gas analysis, radiography, cardiovascular catheterization, and necropsy. Necropsy findings were ventricular septal defect, atrial septal defect, patent ductus arteriosus, and congenital absence of the aortic arch....
McClure JJ, Muscoplat CC, Johnson DW, Senogles DR.A miniaturized method for the mixed lymphocyte culture test in the horse is described. The test is performed in either round- or flat-bottom microtitration tissue culture plates. Concentrations of responsing and stimulating cells are varied, depening on the experiment. Significant discrimination between isogeneic and allogenic mixtures is possible after 120 hours' culture when cells are labeled ([3H]thymidine) for the last 16 to 18 hours of the test.
Boles CL, Raker CW, Wheat JF.An abnormality of the epiglottis and arytenoepiglottic folds that caused epiglottic entrapment was diagnosed in 21 horses. Until recently, this entrapment was poorly understood. Definitive diagnosis of epiglottic entrapment can be made only by endoscopic examination of the epiglottis, arytenoepiglottic folds, and soft palate to differentiate the abnormality from dorsal displacement of the soft palate. Dorsal displacement of the soft palate is often associated with entrapped epiglottis. Epiglottic deformity, especially hypoplasia, is often associated with the entrapment. The abnormality was det...
Rose RJ, Davis PE.Electrocardiograms were reocrded from 153 racehorses and 10 Olympic three-day-event horses. The horses were then grouped into those presented for routine examination, those in which there was a complaint of poor performance, those going to the Montreal Olympics, and those with upper respiratory tract abnormalities. When the ECGs of the four groups were compared on the basis of detection of abnormality, it was found that 93.2% of the poor performance group showed abnormalities of various types. The routine examination group showed 21.1% of horses with abnormal ECGs, and over half of these have ...
Shefstad DK.The lesions caused by larvae of Gasterophilus intestinalis in the cardiac region of the equine stomach were funnel-shaped ulcers surrounded by a rim of hyperplastic epithelial cells. Bacteria were commonly seen on the rim of epithelial cells, at the base of some ulcers, and within the cavities produced by the hooks of the larvae. Cellular debris and mucus were within the ulcer.
Méténier L, Kaminski M.Immunochemical and enzymatic analyses of horse serum carboxylesterase were carried out with respect to the existence of a silent gene. Sera with positive phenotypic expression of esterase, both heterozygotes and presumed homozygotes, were compared with:--sera with positive phenotypic expression but genotypically +/O;--sera with a negative phenotypic expression, i. e. genotypically O/O;--sera of natural +/O "hemi-zygotes": mules (donkey lacking the esterase);--positive sera heated at 60 degrees C;--positive sera after specific inhibition of enzymatic activity. Titration by immunocompetition has...
Smith BP, Reina-Guerra M, Hardy AJ.Feces from 1,451 horses entering a veterinary hospital over a 13-month period were cultured for salmonella. A total of 46 horses (3.2%) yielded 1 or more salmonella-positive fecal cultures. Twenty horses were found to be excreting salmonella in the feces on admission, and 5 of these later had severe diarrhea associated with enteric salmonellosis. Abdominal surgery and other severe stresses were associated with all cases of severe enteric salmonellosis. Serotypes of salmonella isolated included Salmonella agona (15), S anatum (14), S typhimurium (7), S typhimurium var copenhagen (4), S infantis...
Stickle RL, Fessler JF.Equine cryptorchidism was examined by a review of the literature and a retrospective study of 350 horses over a 14-year period. The incidence of left vs right testis retention was nearly equal. On the left side, 75.2% of the retained testes were retained abdominally and 24.8% inguinally; on the right side, 41.8% of the retained testes were retained abdominally and 58.2% inguinally. Preoperative diagnosis by rectal palpation of the vaginal rings was considered a valuable technique, with 87.9% accuracy in 190 horses. Invasive and nonivasive surgical techniques for abdominal cryptorchidectomy and...
Houghton E, Oxley GA, Moss MS, Evans S.A method is described to confirm the presence of 19-nortestosterone metabolites in urine after the administration of veterinary preparations of this anabolic steroid to horses. The method is based upon the detection, by gas chromatography mass spectrometry or selected ion monitoring, of an isomer of estrane-3,17-diol in the urine.
Freeman DE, Naylor JM.An indwelling stomach tube was placed through a cervical esophagostomy in 5 clinically normal horses and in 3 horses requiring artificial alimentation. In all but one case, surgery was performed on conscious horses following tranquilization and infiltration of the surgical sites with a local anesthetic. Six horses were fed liquid rations through the indwelling tubes, which were left in place from 3 to 26 days. After the tubes were removed, the stomas healed rapidly and with minimal complications. Cervical esophagostomy proved to be a safe, easy, and effective method for the provision of extrao...
Pratt GW, O'Connor JT.A biomechanical model of running has been presented. A basic premise has been that the swing time is nearly independent of speed. In fact, both the racehorse and the trotter have nearly equal swing times. Consequently, as speed increases and the stance phase becomes shorter, the horse must compensate by increasing his extension or the length of the airborne phase (or both). The safe speed which allows the horse adequate preparation time for contact of a leg with the ground is calculated, using a stride-by-stride analysis of the motion of the horse. This is seen to be a very sensitive function ...
Rumbaugh GE, Ardans AA, Ginno D, Trommershausen-Smith A.Four procedures for assessment of adequacy of colostral immunoglobulin (Ig) transfer in foals were evaluated. Results of zinc sulfate turbidity test, serum electrophoresis, total serum protein refractometry, and sodium sulfite precipitation test were compared with immunoglobulin G content determined by single radial immunodiffusion. The zinc sulfate turbidity test gave acceptable results for IgG, except that hemolyzed serum samples gave higher than expected values. A correction factor for hemolyzed serum was found to be useful. Serum electrophoresis was a satisfactory method of estimating IgG ...
Johnson AD, Eddy GA, Gangemi JD, Ramsburg HH, Metzger JF.Primary cell cultures, a continuous cell line, and a diploid cell line were grown on an artificial capillary system. The cells were subsequently infected with Venezuelan equine encephalitis virus, and viral replication was studied. Extracellular fluids harvested from this system contained high titers of virus and were relatively free of cell debris.
Monin T.Physeal fractures of the tuber olecranon of 4 horses were treated, using the tension band method of compression fracture repair. A cortical bone screw and Steinmann pin were placed through the proximal fragment into the distal parent bone parallel to the palmar border of the olecranon. The tension band was placed dorsal to the Steinmann pin and anchored in a hole through the shaft of the ulna 10 cm distal to the tuber olecranon. Of the 4 foals, 2 became pasture sound, 1 is now being worked under saddle, and the 4th showed no signs of lameness 5 months after surgery.
Valdez H, Adams OR, Peyton LC.Of 124 horses determined to have navicular disease during a 5-year period, 6 had clinical and radiographic signs of the disease in both hindlimbs. These 6 were all castrated males, ranging in age from 3 to 12 years, and were used for work of similar nature: roping, cutting, and pleasure. Treatment consisted of posterior digital neurectomy and corrective shoeing in 2 cases, posterior digital neurectomy alone in 2 cases, and corrective shoeing alone in 2 cases. Following treatment, lameness subsided, and all 6 horses were returned to full use.
Blähser S.In the thyroid glands of the horse, pig, deer, mole, and rat, C-cells could be demonstrated by means of the immunocytochemical PAP-technique using rabbit antisera against human calcitonin. Only in ruminants, the cross-reaction between the intracellularly stored antigen and the antibodies used appeared to be incomplete.
Papkoff H, Bewley TA, Ramachandran J.Pregnant mare serum gonadotropin and its subunits have been further characterized. Ultracentrifugation of the gonadotropin at pH 1.3 and 11.5 showed little evidence of dissociation compared to pH 8.2. Highly purified subunits are obtained by urea dissociation and ion-exchange chromatography followed by gel-filtration. Circular dichroism spectra of the gonadotropin and its subunits are much like those of ovine lutropin and its subunits in that there is little evidence for secondary structure and one or more tyrosine residues are inaccessible in the intact gonadotropin compared to the subunits. ...
Orsini JA, Buonanno AM, Richardson DW, Nunamaker DN.A Salter-Harris type-II fracture of the distal portion of the femur in a 1-year-old Pony of America was repaired by use of lateral plating combined with interfragmentary compression. The configuration of the fracture and the method of internal fixation with a condylar buttress plate were unique and resulted in primary bone healing, seen at the 5-month follow-up examination.
YoungLai EV, Jarrell JF.Granulosa cells were harvested from mares at various stages of the oestrous cycle and incubated in Krebs-Ringer bicarbonate buffer with 1 beta,2 beta[3H]androstenedione as substrate. The release of 3H2O expressed as CPM/h/mg protein varied from 44000 to 768000 in follicles from 7 mares. The release of 3H2O was not significantly altered by luteinizing hormone, follicle stimulating hormone or pregnant mare's serum gonadotrophin. There was a significant negative correlation between the release of 3H2O and the concentration of progesterone in the follicular fluid. Based on the assumption that the ...
Berry S.Hemangiosarcoma in the spinal canal was diagnosed in a 25-year-old stallion showing progressive and symmetrical 4-limb ataxia, proprioceptive deficits, and weakness. On necropsy, an extradural mass consisting of spindle-shaped cells and numerous free erythrocytes was found at the level of C7-T1. Immunohistochemical staining confirmed a neoplasm of endothelial origin.
Squires EL, Cook NL.This article describes in detail the procedures for collection of equine oocytes using a transvaginal ultrasound probe. Success in obtaining oocytes from humans, bovines, and horses are presented. The effect of repeated follicular aspiration of both cattle and horses is reviewed.
May SA, Hooke RE, Lees P.Equine interleukin-1 has been produced from peripheral blood monocytes by stimulation with E. coli lipopolysaccharide. Sephacryl S200 gel filtration revealed a molecular weight of 17-18 kD. Chromatofocusing of the 17-18 kD peak identified four active fractions. Two major peaks were detected at pH 6.7 and pH 7, with smaller peaks at pH 6.3 and pH 5.9. The pI 7 molecule is probably the equine form of IL-1 beta.
Ganjam VK, Kenney RM, Flickinger G.The pattern of plasma progestagen levels during the oestrous cycle was similar to that previously reported except for lower peak levels. The lack of significant difference (p less than 0-01) between CPBA and RIA values suggests that progesterone itself is the major component during the oestrous cycle. Progesterone levels during the first and second post-parturient oestrous cycles were similar to those observed during the cycle of the non-pregnant mare. During pregnancy there were two peaks of plasma progestagens. The first, which occurred during the 3rd month, coincided with high levels of PMS...
Waugh SL, Campbell KB, Klavano PA, Grant BD.A surgical thoracotomy and implantation of an electromagnetic flow probe around the ascending aorta and catheters in the left ventricular (LV) apex of the horse were evaluated. Sixteen operations were done: 4 horses were used for acute experiments, 4 horses died from surgical manipulation, and 8 horses were studied chronically for 18 to 57 days. The electromagnetic flow probe allowed continuous measurement of stroke volume and heart rate. The LV apical catheters, in conjunction with thermal dilution techniques and pressure-sensitive devices, allowed measurement and calculation of mean arterial...
Barnes RJ, Comline RS, Jeffcott LB, Mitchell MD, Rossdale PD, Silver M.The concentrations of 13, 14-dihydro-15-oxo-prostaglandin F(PGFM), the stable metabolite of prostaglandin F, were measured in the plasma of catheterized mares and foetuses and non-catheterized thoroughbred mares and ponies during the last months of gestation. The plasma concentration of PGFM increased gradually towards term in all groups of animals. During the operation for insertion of catheters, maternal and foetal concentrations of PGFM were high, but the values fell to basal levels 24--48 h after the operation. It was found the preoperative starvation (24 h) led to a rise in the concentrat...
Aragunde Vieytes R, Viñoles Gil C, Gastal GDA, Cavestany D.In order to assess the effect of equine chorionic gonadotropin (eCG) administered on Day 5 or 7 of a fixed-time artificial insemination protocol (FTAI) in anestrous suckled beef cows, two experiments were performed to determine the following endpoints: Experiment 1 (n = 22), preovulatory follicle (POF) diameter, ovulation time, corpus luteum (CL) area, estradiol (E2) and progesterone (P4) concentrations; and Experiment 2 (n = 676), a field trial to evaluate conception rate using the same experimental design. In both experiments, a synchronization protocol using estradiol benzoate (EB) (Day...
Yarbrough TB, Lee MR, Hornof WJ, Schumacher HR, O'Brien TR.To determine the effects of intraarticular administration of Samarium-153 (153Sm) bound to hydroxyapatite microspheres (153SmM) on an osteochondral chip-induced synovitis. Methods: Sixty days after implantation of autogenous osteochondral fragments in the middle carpal and metacarpophalangeal joints, 153SmM was administered into 1 joint of each type. The contralateral joints were used as untreated controls. Methods: Fifteen horses without preexisting joint disease were randomly divided into 2 groups (7 in the carpal group, 8 in the metacarpophalangeal group). Methods: Horses had osteochondral ...
Velasco-Murillo V.It exists controversies about if the effects and benefits of the esterified estrogens could be similar to those informed for equines, because its chemical composition and bioavailability are different. Esterified estrogens has not delta 8,9 dehydroestrone, and its absorption and level of maximum plasmatic concentrations are reached very fast. In United States of America and another countries, esterified estrogens has been marketed and using for treatment of climacteric syndrome and prevention of postmenopausal osteoporosis, based on the pharmacopoiea of that country, but the Food and Drug admi...