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.
Lakritz J, Wilson WD, Watson JL, Hyde DM, Mihalyi J, Plopper CG.To determine whether oral administration of erythromycin alters the inflammatory response to bronchoalveolar lavage (BAL) in young horses. Methods: 12 healthy, unweaned, mixed-breed foals of either sex, between 2 and 4 months old. Methods: BAL was performed; 250 ml of phosphate-buffered saline solution (300 mOsm, pH 7.4) was administered in 50-ml aliquots. Foals were carefully monitored for 4 days, then erythromycin base (25 mg/kg of body weight, PO, q 12 h) was given to foals of the treated group. After 4 days, foals were reanesthetized, and the same lung was relavaged. Cytologic examination ...
Tetens J, Ross MW, Lloyd JW.To assess the effect of incomplete, midsagittal fractures of the proximal phalanx (P1) on racing performance in Standardbreds. Methods: Retrospective cohort study. Methods: 49 Standardbred horses admitted to the George D. Widener Hospital for Large Animals between July 1986 and December 1992 with a definitive radiographic diagnosis of an incomplete, midsagittal fracture of P1 and a known method of treatment. Methods: Performance index and racing time were compared before and after diagnosis and treatment of fracture, using ANOVA that controlled for the effects of horse, gender, age, track leng...
Lisiecki P, Sobiś-Glinkowska M, Mikucki J.Under iron-restricted conditions staphylococcal strains could utilize in vitro several animals body iron sources in form of bovine haemoglobin, hemin, lactoferrin and transferrin, ovotransferrin, horse myoglobin ferritin and cytochrome C. Spectrum of utilized iron sources was not dependent on species affiliation and kind of siderophores system. Strains isolated from clinical materials utilized largest spectrum of animal iron body sources.
Vörös K.Quantitative two-dimensional echocardiography (2DE) was introduced into equine cardiology in the early 1990s. At first, linear and area dimensions and left ventricular volume were validated by the comparison of parameters determined during in vitro 2DE and autopsy measurements. Based on these studies, tomographic planes and intracardiac reference points for in vivo measurements were established and 2DE values have been determined for healthy adult horses by various authors. These data were similar to each other and proved to be comparable with M-mode echocardiography measurements. However, dif...
Koivunen AL, Maisi P, Konttinen YT, Prikk K, Sandholm M.The collagenolytic activity and its sensitivity to doxycycline inhibition in tracheal aspirates (TA) of horses with chronic obstructive pulmonary disease (COPD) was analyzed with SDS-PA gel electrophoresis (SDS-PAGE), using Type 1 collagen as the substrate. Both autoactive and total collagenase activities were significantly higher in TAs of horses with symptomatic COPD than in TAs of healthy horses. Doxycycline inhibition studies suggest that most of the TA collagenase is of the neutrophil type (MMP-8), but some is derived from other cells such as fibroblasts and monocyte/macrophages (MMP-1) a...
Chopin JB, Sigler L, Connole MD, O'Boyle DA, Mackay B, Goldstein L.This report describes an infection of a horse's cornea caused by Cladorrhinum bulbillosum. Minor surgery and treatment with antibiotics successfully resolved the infection. The only previous reported case involving this fungus was an Argentinian boy who was infected while working with horses.
Johnson E, Atwill ER, Filkins ME, Kalush J.Cryptosporidium parvum and Giardia duodenalis are now recognized as primary enteric pathogens in animals and humans. Regulatory agencies, such as the Environmental Protection Agency are under increasing pressure to reduce the concentration of these protozoa in surface waters. Given the popularity of recreational riding of horses on public land in California backcountry, concerns have been raised by various regulatory agencies as to whether horses used for backcountry recreation are a significant source of C. parvum and G. duodenalis for the environment. The prevalence of fecal shedding of Cryp...
Paweska JT, Binns MM, Woods PS, Chirnside ED.A seroepidemiological survey of donkeys in South Africa (n = 4300) indicated a wide distribution and increasing prevalence of antibodies to equine arteritis virus (EAV). Donkey sera inhibited equine arteritis virus infection in virus neutralisation (VN) tests and in ELISA specifically bound to a recombinant antigen derived from the Bucyrus isolate of EAV. These results suggest that donkeys have been exposed to the same serotype of this virus as circulates among horses. A good correlation existed between EAV neutralising antibody titres and ELISA absorbance values (0.8631); the ELISA was sensit...
Sharp DC, Thatcher MJ, Salute ME, Fuchs AR.The effect of transcervical endometrial biopsy on the concentrations of plasma immunoreactive oxytocin and 15-keto-13,14-dihydro-prostaglandin F2 alpha (PGFM) was studied in 18 pony mares on days 8, 12 and 14 after ovulation, days 12 and 14 of early pregnancy and at oestrus. Five biopsy specimens were taken within 15 min and consecutive specimens from each mare were pooled two (A) and three (B) together for measurement of the number of oxytocin receptors. Blood samples were collected at intervals of 5 min for 15 min beginning just before the initial biopsy. Biopsy procedure elicited prompt oxy...
Thayer JF, Hahn AW, Pearson MA, Sollers JJ, Johnson PJ, Loch WE.High heart rate variability (HRV) has been associated with more efficient autonomic control, allowing more responsivity and sensitivity to changing environmental demands. Previous results from spectral analysis of interbeat intervals of equine heart rate (HR) indicated increased HRV, reflecting more effective vagal control of the heart. This study focuses on characterizing equine HR and HRV during increasing then decreasing physical demand. A non-invasive ambulatory monitoring system continuously records HR and HRV as horses exercise on a high speed equine treadmill at increasing then decreasi...
Reilas T, Katila T, Mäkelä O, Huhtinen M, Koskinen E.Intrauterine fluid (IUF) was collected using a tampon from mid-oestrous mares (n = 57) with and without ultrasonically detectable accumulations of free intraluminal fluid. Bacteria were cultured and neutrophils counted from all samples (n = 57). Total protein concentration, trypsin-inhibitor capacity (TIC), and plasmin, beta-glucuronidase (B-Gase) and N-acetyl-beta-D-glucosaminidase (NAGase) activities were determined in 27 IUF samples. The motility of spermatozoa in the presence of IUF, IUF extended with Kenney's medium (1:1) and Kenney's medium alone was analysed in 9 samples using a Hamilto...
Blissitt KJ, Young LE, Jones RS, Darke PG, Utting J.Measurement of cardiac output by Doppler echocardiography were compared to simultaneous measurements by thermodilution in 9 conscious horses. In the Doppler technique, mean blood flow velocities for estimation of cardiac output were recorded from the aorta and pulmonary artery. The flow area of each vessel was calculated from the vessel diameter, measured from a 2-dimensional ultrasound image. Differences in the site and method of measuring the vessel diameter altered the estimation of cardiac output by the Doppler method. Cardiac output was modified by the i.v. infusion of 4 micrograms/kg bwt...
Murphy DJ, Nixon AJ.To examine the site-specific and dose-dependent effects of insulin-like growth factor I (IGF-I) on normal equine tendon in vitro. Methods: Superficial digital flexor tendon explants derived from a euthanatized 3-year-old horse. Methods: Explants in culture were treated with 0, 100, 250, or 500 ng of IGF-I/ml for 14 days with an end-stage radiolabel of 20 microCi of [3H]proline/ml or 5 microCi of [3H]thymidine/ml. The tendon tissues were then analyzed biochemically for hydroxyproline content by reverse-phase high-performance liquid chromatography, DNA content by fluorometry, and glycosaminoglyc...
Allen AL, Scott WM, Cook SJ, Fretz PB, Doige CE.Studies were conducted to determine the effects of delaying the separation of serum from the clot and of long-term storage of serum samples on the measurement of thyroid hormones in blood from horses using a fluorescence polarization immunoassay. The measured concentrations of T3 and T4 were not affected by leaving serum on the clot for as long as 24 hours at room temperatures. Storage of serum for 19 to 22 months at -20 degrees C resulted in significant increases of measured T4, but not T3. These studies support previous work demonstrating that thyroid hormones are resistant to degradation, i...
Höglund J, Ljungström BL, Nilsson O, Lundquist H, Osterman E, Uggla A.A survey was performed on the occurrence of some internal parasites in 461 horses (1-30 years old) slaughtered from October 1992 to September 1993 at the Linköping abattoir in central Sweden. Macroscopical examination was carried out specifically for parasites of the tear ducts and conjunctival sacs of the eyes, and of selected parts of the alimentary tract and cardio-vascular system. The following parasites were found in selected parts of the large intestine: encapsulated cyathostome larvae (in 35.6% of the horses), and mature strongyle worms (17.4%); in the stomach: Gasterophilus intestinal...
Lillich JD, Bertone AL, Malemud CJ, Weisbrode SE, Ruggles AJ, Stevenson S.To compare the biochemical, histochemical, and immunohistochemical profiles of articular cartilage from horses with naturally acquired distal tibial osteochondrosis (OC) with cartilage from a similar location in clinically normal horses. Methods: 9 affected horses (group 1, 16 OC lesions) and 4 control horses (group 2, 8 normal osteochondral specimens). Methods: OC specimens were collected during arthroscopic removal of the fragment, and control specimens were collected by aseptic osteotomy. Uronic acid, total protein, total glycosaminoglycan (GAG), chondroitin sulfate (CS), and keratan sulfat...
Sime A, McKellar Q, Nolan A.A serum-free cell culture method was developed for equine tracheal epithelial cells which allowed the growth and characterisation of the phenotypical properties of this cell type. Several variables influenced the efficacy of the attachment and growth of the isolated cells. Serum and a collagen matrix were essential components for efficient cell attachment. Once attachment had occurred, cell growth was enhanced by a serum-free medium containing bovine pituitary extract, retinoic acid, insulin, hydrocortisone, transferrin, epidermal growth factor, adrenaline and triiodothyronine. The mean time t...
Parraga ME, Spier SJ, Thurmond M, Hirsh D.The purpose of this study was to evaluate the effects of probiotic administration on the prevalence of fecal shedding of Salmonella, the prevalence of postoperative diarrhea, the length of antimicrobial therapy, and the length of the hospitalization stay during the postoperative period in horses with colic. Two commercially available probiotics for horses were used in a double-blind prospective study of 200 horses undergoing surgery for colic. Probiotic or placebo was administered PO once a day for 7 days postoperatively, and fecal cultures for Salmonella were obtained daily for 10 days. After...
Platt D, Wright IM.The history, clinical features, radiological findings, treatment and outcome of 15 horses with chronic tenosynovitis of the carpal extensor tendon sheaths are reported. The condition was seen most commonly in horses used for jumping and penetration of the tendon sheaths by thorns was the most common aetiology. Treatment involved surgical resection of the hyperplastic synovial membrane, and adhesions within the tendon sheath, with primary closure. When combined with early postoperative physiotherapy this was found to be an effective method of treatment. All horses in this series were not lame a...
Ruohoniemi M, Laukkanen H, Ojala M, Kangasniemi A, Tulamo RM.The ossification of the collateral cartilages of the distal phalanx was evaluated in dorsopalmar radiographs of the front feet of 202 Finnhorses (101 females and 101 males, aged six months to 20 years) with reference to the sex, age, body measurements and type of horse. Ossification was more common and more extensive in females than in males from about two years of age. In females, the lateral cartilages were significantly more ossified than the medial cartilages; in males, ossification was more symmetrical in the cartilages of each foot. The amount of ossification increased rapidly during the...
Thayer JF, Hahn AW, Sollers JJ, van Doornen L, Johnson PJ.Using a microprocessor controlled Ambulatory Monitoring System (AMS) developed by one of us (LvD), we have been studying the changes in and control of heart rate in the resting horse. The system provides us with InterBeat Intervals (IBI in milliseconds), motion sensing, and a time domain measure (mean successive differences: MSD) of heart rate variability for periods up to 72 hours. Thoracic impedance is also available but parameters for the equine chest are not currently available. The system is completely noninvasive, small, and carried on a surcingle worn by the subject. The equine subject ...
Adams MR, Register TC, Golden DL, Wagner JD, Williams JK.Although estrogen replacement therapy is associated with reduced risk of coronary heart disease and reduced extent of coronary artery atherosclerosis, the effects of combined (estrogen plus progestin) hormone-replacement therapy are uncertain. Some observational data indicate that users of combined hormone replacement consisting of continuously administered oral conjugated equine estrogens (CEE) and oral sequentially administered (7 to 14 days per month) medroxyprogesterone acetate (MPA) experience a reduction in risk similar to that of users of CEE alone. However, the effects of combined, con...
Kyvsgaard NC, Høier R, Brück I, Nansen P.Ionizing irradiation and binary ethylenimine treatment have previously been shown to be effective for in-vitro inactivation of virus in biological material. In the present study the 2 methods were tested for possible effects on measurable concentrations of reproductive hormones in equine plasma (luteinizing hormone (LH), folliclestimulating hormone (FSH), progesterone (P4), and oestradiol-17 beta (E2)). The inactivation methods were electron beam irradiation with a dose from 11 to 44 kGy or treatment with binary ethylenimine (BEI) in concentrations of 1 and 5 mmol/L. Generally, there was a clo...
Kaneene JB, Miller R, Ross W, Gilbert L.Data from two 12 month prospective monitoring programs that followed management, economics and animal health from randomly-sampled equine operations in Michigan were used to determine patterns of health maintenance. Health maintenance measures were grouped, and average uses per year were computed for the most-common measures reported: respiratory, Potomac Horse Fever, neurological and multiple-system vaccinations, deworming, and general farrier work. Factors examined for potential association with health maintenance measure use were numbers of equids and horse-days on the operation, average ag...
Platt D, Wells T, Bayliss MT.Equine chondrocytes were cultured in vitro for 30 days in ionically gelled alginate beads. The alginate polymerises into a stable gel in the presence of divalent cations (calcium), and rapid depolymerisation in the presence of a calcium chelator releases the viable chondrocytes. The chondrocytes maintained a spherical appearance for 30 days in culture, in marked contrast to monolayer cultures, which develop a dedifferentiated fibroblastic morphology. The major proteoglycan molecule produced by the encapsulated chondrocytes was aggrecan, of similar hydrodynamic size to aggrecan molecules presen...
Mealey KL, Matthews NS, Peck KE, Ray AC, Taylor TS.To compare plasma disposition of phenylbutazone and its metabolite oxyphenbutazone after i.v. administration of phenylbutazone in horses and donkeys. Methods: 4 clinically normal horses and 6 clinically normal donkeys. Methods: Blood samples were collected from each animal at time 0 (before) and 5, 10, 20, 30, 45, 60, 90, 120, 180, 240, 300, 360, and 480 minutes after i.v. administration of a bolus dose of phenylbutazone. Serum was analyzed in triplicate by use of high-performance liquid chromatography for determination of phenylbutazone and oxyphenbutazone concentrations. The serum concentrat...
Choi YH, Love LB, Varner DD, Hinrichs K.The effect of medium-to-embryo ratio on blastocyst development of equine embryos from oocytes with compact cumuli was evaluated in the present experiment. In addition, two methods for holding oocytes before in vitro maturation were compared. In Experiment 1, oocytes cultured with roscovitine for 16-18h before maturation were fertilized by intracytoplasmic sperm injection and cultured individually in 2.5, 5, 10 or 50microl droplets. In Experiment 2, oocytes were either cultured with roscovitine or held in a modified M199 with 20% serum at room temperature (EH treatment) for 16-18h, then matured...
Peixoto Rabelo I, Barroco de Paula V, Carvalho Bustamante C, Santana AM, Gomes da Silva D, Baldassi AC, Canola PA, Araújo Valadão CA.Horses submitted to carbohydrate overload can develop laminitis due to changes in cecal pH and microbiota, followed by an increase in transmural absorption of luminal content, including bacterial toxins. In response to acute injury there is hepatic overproduction of several proteins known as acute phase proteins (APP). Few studies have evaluated protein fractionation to characterize the inflammatory response in acute laminitis. The aim of this study was to test the viability of an experimental model to induce acute laminitis, using a single carbohydrate overload, and the influence of a bufferi...
Menzies-Gow NJ, Marr CM.The repeatability and sensitivity of Doppler ultrasonographic measurement of lateral digital arterial and venous blood flow has not been previously determined. Doppler ultrasonography was used to measure blood flow within the forelimb lateral digital vessels in one normal adult Thoroughbred horse on six occasions and in six normal adult Thoroughbred horses on three occasions, each occasion being at least 1 h apart, to determine the within- and between-horse variation. The values obtained from the right and left lateral digital vessels did not differ significantly. The within-horse coefficients...
van de Pol C, Sloet van Oldruitenborgh-Oosterbaan MM.Measuring the height at the withers of a pony is one of the requirements of the Fédération Equestre Internationale (FEI), before competitors can participate in an official pony event. A pony has to be measured each year until it is eight years old. With and without shoes the height at the withers must be below 149.0cm and 148.0cm, respectively. When a pony exceeds the regulated height, it is excluded from participating in FEI pony competitions. Besides being excluded from competing, the selling price of the pony decreases dramatically, because the animal is then classified as a horse. For th...
Sherlock CE, Kinns J, Mair TS.The records of 41 horses with previously undiagnosed foot pain that had been examined by standing magnetic resonance imaging were reviewed and follow-up information was obtained from their owners two years after the examination. A range of soft tissue and osseous abnormalities were identified, with multiple lesions frequently occurring. Deep digital flexor tendonitis was recorded in 12 of the horses, and distension of the distal interphalangeal joint was identified in 15, but it was not always associated with lameness; in contrast, distension of the navicular bursa was always associated with l...
Rathnam P, Fujiki Y, Landefeld TD, Saxena BB.Six hundred milligrams of follicle-stimulating hormone (FSH), containing 110 NIH-FSH-S1 units/mg, was isolated from 9 kg of equine pituitary glands. The equine FSH was dissociated into alpha- and beta-subunits. A tentative amino acid sequence of the alpha-subunit was determined. The alpha-subunit contained 82 amino acids. The equine FSH-alpha is shorter by 10 to 14 amino acids at the NH2 terminus and has several substitutions at several positions as compared with human FSH-alpha and bovine thyroid-stimulating hormone-alpha. At the intraspecies level, the alpha-subunits of human FSH, human lute...
Kramer JW, Nickels FA, Bell T.Examination of effusions from body cavities must include a search for neoplastic as well as inflammatory cells. Neoplastic cells found in the thorax are generally derived from adenocarcinomas or mesotheliomas. Mesotheliomas are relatively uncommon and the neoplastic cells found in effusions are difficult to differentiate from activated cells in inflammatory effusions. An ante-mortem diagnosis of mesothelioma was made in a mare on the basis of the large volume of fluid produced, the pleomorphic mesothelial cells, the polyp formation and the absence of PAS staining material after digestion of th...
Tang FP, Leung GN, Wan TS.A capillary electrophoresis-mass spectrometry (CE-MS) method for the analysis of quaternary ammonium drugs in equine urine was developed. Quaternary ammonium drugs were first extracted from equine urine by ion-pair extraction and then analysed by CE-MS in the positive electrospray ionization (ESI) mode. Within 12 min, eight quaternary ammonium drugs, each at 1 ng/mL in horse urine, could be detected. The confirmation of these drugs in urine samples was achieved by capillary electrophoresis tandem mass spectrometry (CE-MS/MS). A direct comparison of this method was made with existing liquid chr...
Spence KL, O'Sullivan TL, Poljak Z, Greer AL.On-farm biosecurity measures are an important part of a control plan to minimize the introduction and spread of infectious diseases, such as equine influenza, in an equine facility. It can be challenging, however, to evaluate the efficacy of biosecurity measures under field conditions. We used an agent-based computer simulation model to describe the impact of: i) preventive vaccination; ii) reduced horse-to-horse contact; and iii) a combination of vaccination and reduced contact during an outbreak of equine influenza in a simulated horse facility. The model demonstrated that the most effective...
Papasouliotis K, Tennant KV, Dodkin S, Mason J.Falcor 350 is a wet-reagent biochemistry analyser that is available for in-house use. The aim of this study was to compare the results produced by this analyser with those obtained by the KoneLab 30i that served as the reference instrument. Blood samples from 60 clinical cases were analysed for urea, creatinine, total proteins, albumin, creatine kinase, aspartate aminotransferase, alkaline phosphatase, total bilirubin, total calcium, phosphate, sodium, and potassium using both instruments. Good to excellent correlations (r s value) value) were identified for creatinine (0.88), total proteins (...
Pratt SL, Bowen M, Hallowell GH, Shipman E, Bailey J, Redpath A.Equine glandular gastric disease (EGGD) is a common condition of the horse. Misoprostol is reported to be superior to oral omeprazole and sucralfate for treatment. Long-acting intramuscular injectable omeprazole (LAIOMEP) is a novel treatment shown to be effective in a small population. This study aimed to determine LAIOMEP efficacy compared to misoprostol and oral omeprazole and identify characteristics that predict treatment outcome. All horses that underwent gastroscopy between 2012 and 2019 were reviewed. Lesions were characterised by 4 blinded observers, all of whom are diplomates in equi...
Equine protozoal myeloencephalitis (EPM) is a neurological disease caused by Sarcocystis neurona. Immunofluorescence antibody tests (IFATs) have been widely used to identify exposure of horses to S. neurona in Brazil. Here we used IFAT to search for IgG antibodies against Sarcocystis falcatula-like (Dal-CG23) and S. neurona (SN138) in sera from 342 horses sampled in Campo Grande, Mato Grosso do Sul state (Midwestern), and São Paulo, São Paulo state (Southeastern), Brazil. The 1:25 cutoff value was chosen to maximize sensitivity of the test. IgG antibodies against S. neurona were detected in ...
Klein R, Oláh J, Mihók S, Posta J.The Mezőhegyes Stud was founded in 1784 where three different horse breeds were developed: the Furioso-North Star, the Gidran, and the Nonius. These breeds were based on the same mare population, but each breed had different utilization purposes. Our aim was to analyze the pedigree information of these three indigenous breeds. The genealogical information was traced back from the actual breeding population back to the founder animals, and the final database contained more than 47,000 horses. The reference populations were defined as the registered breeding animals in 2019. The complete genera...
Sellers AF, Lowe JE, Cummings JF.Some support for both serotonin and substance P as biotransmitters in the equine large colon is presented. Close arterial injections of small quantities of each of these were effective, respectively, in stimulating marked increases in coordinated pressure peaks in the vicinity of the pelvic flexure, with modest (serotonin) or marked (substance P) increase in colon artery blood flow. Both the acaricide, amitraz, and the tranquilizer xylazine appeared to act on the equine large colon via yohimbine-sensitive alpha 2-adrenergic receptors.
Dzięgielewska A, Dunislawska A.Mitochondria are an essential part of most eukaryotic cells. The crucial role of these organelles is the production of metabolic energy, which is converted into ATP in oxidative phosphorylation. They are also involved in and constitute apoptosis, the site of many metabolic processes. Some of the factors that negatively affect mitochondria are stress, excessive exercise, disease, and the aging process. Exercise can cause the release of large amounts of free radicals, inflammation, injury, and stress. All of these factors can contribute to mitochondrial dysfunction, which can consistently lead t...
Chaffin MK, Honnas CM, Crabill MR, Schneiter HL, Brumbaugh GW, Briner RP.A 4-month-old male Quarter Horse was referred for evaluation of urinary incontinence. Physical examination revealed clinical signs consistent with cauda equina syndrome. Radiography revealed diskospondylitis of S2 through S4. Infected bone was surgically curretted, and drainage was established for an associated paravertebral abscess. Rhodococcus equi was isolated from specimens of bone and from fluid samples obtained from the paravertebral abscess. Bethanechol was administered to stimulate urination. Erythromycin and rifampin were administered for 120 days. The foal's neurologic dysfunction re...
Putt W, Whitehouse DB.This paper reports genetic variation at the prealbumin (Pr), postalbumin (Pa) and transferrin (Tf) loci in Equus przewalskii found using thin layer isoelectric focusing and an amphoteric separator. The method resolves all three loci plus serum esterase (Es) on a single gel, and typing of all four loci is readily achieved. In addition to the esterase alleles previously reported by Fisher & Scott (1979), five alleles were found at the Pr locus, three at the Pa locus and six at the Tf locus. Analysis of several mating types confirms inheritance is autosomal and codominant for all four loci.
Fitzgerald BP, I'Anson H, Loy RG, Legan SJ.To determine whether tonic LH secretion in ovariectomized mares is characterized by pulsatile release, frequent blood samples (every 15 min) were collected from 5 ovariectomized horse mares in nine 8-h periods between February and May. Mean serum LH concentrations increased 9-fold and were associated with a 4-fold increase in mean LH pulse frequency. These results provide the first evidence of pulsatile LH release in ovariectomized mares and suggest that the increasing daylengths of the spring months may increase serum LH by increasing LH pulse frequency.
Vollmerhaus B, Roos H, Gerhards H, Knospe C.The canine teeth of the horse developed phylogenically from the simple, pointed, short-rooted tooth form of the leaf eating, in pairs living, Eocene horse Hyracotherium and served up to the Oligocene as a means of defense (self preservation). In the Miocene the living conditions of the Merychippus changed and they took to eating grass and adopted as a new behavior the life in a herd. The canine teeth possibly played an important role in fights for social ranking; they changed from a crown form to knife-like shape. In the Pliohippus the canine tooth usually remained in male horses and since the...
Patterson SD, Auer D, Bell K.The induction of an acute phase response in four horses by adjuvant administration was used to examine the effect on the levels of plasma proteins. Blood parameters (packed cell volume, total plasma protein, red blood cell count, haemoglobin concentration) were monitored to follow the progress of the acute phase response in parallel with the examination of plasma proteins. Plasma protein levels were determined by densitometry from the electrophoretic patterns of three different gel systems. Haptoglobin and alpha 1 B glycoprotein were shown to be positive acute phase reactants whereas albumin w...
Romagnoli U, Macchi E, Romano G, Motta M, Accornero P, Baratta M.The aim of this work is to investigate on plasma profiles of leptin and estradiol 17beta during the interpartum period and leptin concentrations in the milk and in the colostrum during the period from parturition to the successive delivery in mare. Leptin plasma concentration varied from 5.1+/-2.3 ng/ml after the first parturition (week 0) to 3.0+/-0.7 at week 21 (p<0.05), then it increased to maximal level at week 49 (6.9+/-1.0 ng/ml, p<0.05). Leptin concentration in the colostrum and in the milk has been significantly (p<0.05) higher than that in plasma samples at week 1 (milk 8.8+/...
Watson ED, Heald M, Tsigos A, Leask R, Steele M, Groome NP, Riley SC.Ten mares were studied from February (winter anoestrus) to their second ovulation in the breeding season to investigate the relationship between resumption of ovarian cyclicity in the spring and circulating concentrations of FSH, inhibin A and inhibin isoforms containing pro- and -alphaC immunoreactivity. An additional four mares were studied during one oestrous cycle. Growth and regression of ovarian follicles were monitored by transrectal ultrasonography. The frequency of blood sampling varied from three times a week to once a day, depending on the follicular activity present. Concentrations...
Jeawon SS, Katz LM, Galvin NP, Fogarty UM, Duggan VE.Although umbilical cord blood gas analysis is considered the best way to assess in utero oxygenation in human neonates, there is limited evaluation of this method in equine neonatology. Our objectives were to assess the practicality of obtaining umbilical cord blood gas samples in the field and to determine umbilical cord arterial and venous blood gas reference intervals (RI) for healthy, newborn foals. Thoroughbred foals >320 days gestation from healthy mares with uneventful pregnancies at one stud farm were evaluated. All parturitions were observed, with paired umbilical arterial and venous ...
Badial PR, Teixeira RBC, Delfiol DJZ, da Mota LSLS, Borges AS.Overo lethal white foal syndrome (OLWFS) is a genetic disorder caused by a dinucleotide mutation in the endothelin receptor type B (EDNRB) gene leading to the death of affected foals shortly after birth. The use of rapid and reliable genetic testing is imperative for the early diagnosis of the mutation avoiding, therefore, either additional suffering or the production of affected animals. In the present study, we developed and validated a high-resolution melting (HRM) genotyping assay to detect the OLWFS causative mutation, and we also determined the frequency of heterozygotes among American P...
