Equine Science encompasses the study of horses and their management, health, and performance. This field integrates various scientific disciplines such as biology, genetics, nutrition, physiology, and veterinary medicine to understand and improve the well-being and capabilities of horses. Areas of focus include equine anatomy, reproduction, behavior, and disease prevention. Research in equine science aims to enhance horse care, optimize training and performance, and address health challenges. This page compiles peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine science, providing insights into the latest advancements and methodologies in the field.
Meintjes M, Graff KJ, Paccamonti D, Eilts BE, Paul JB, Thompson DL, Kearney MT, Godke RA.When aspirating ovarian follicles in pregnant mares to obtain oocytes for in vitro fertilisation (IVF), the effect of the manipulation on circulating concentrations of progesterone may be an important consideration in terms of the maintenance of pregnancy. The object of this study was to compare the effects of 3 different forms of transvaginal ultrasound-guided follicle aspiration (Treatment 1, no aspiration, n = 4; Treatment 2, aspirate only follicles > or =20 mm in diameter, n = 7; Treatment 3, aspirate all visible follicles, n = 7) on peripheral plasma progesterone concentrations between Da...
Vazquez de Mercado R, Stover SM, Taylor KT, Zarucco L, Willits NH.To determine anatomic landmarks for a lateral approach for arthrocentesis of the proximopalmarolateral aspect of the distal interphalangeal (DIP) joint in horses and the likelihood of entering synovial structures other than the DIP joint through this approach. Methods: Prospective study. Methods: Paired forelimbs of 8 cadavers and 12 horses. Methods: Anatomic preparations were used to determine anatomic landmarks. Positive-contrast arthrography was used to determine which structures were entered. Results: Landmarks for the lateral approach included a depression in the proximal border of the la...
Eggleston-Stott ML, Delvalle A, Dileanis S, Wictum E, Bowling AT.The equine dinucleotide microsatellite HMS7 is part of a microsatellite panel utilized in a parentage verification programme at the Veterinary Genetics Laboratory (Davis, California, USA). Apparent non-Mendelian inheritance was noted when a Quarter Horse mare was excluded as the parent of two offspring based on analysis of the HMS7 locus. The mare's DNA type qualified her as a parent of the offspring at an additional 20 microsatellite loci. The three animals appeared homozygous for HMS7 with each possessing an allele different from that of the other two animals. Polymerase chain reaction prime...
Takehana K, Masty J, Yamaguchi M, Kobayashi A, Yamada O, Kuroda M, Park YS, Iwasa K, Abe M.Ultrastructure, lysozyme and glycoconjugate activity in duodenal Paneth cells were observed concurrently in the horse. Paneth cells were seen to uniformly line the base of the equine intestinal glands. The round secretory granules have centrally located electron densities with peripherally located electron lucent halos. Histochemically, the peripheral halo layer was positively stained for carbohydrates by the periodic acid-thiocarbohydrazide-silver protein-physical development (PA-TCH-SP-PD) method and the entire granules reacted positively to the WGA. The central core area reacted with anti-l...
Voigt G.The author informs on up to date identification methods of horses. The implantation of passive transponders is a practicable method for marking of horses. Because it gives less pain to horses, this method is to prefer. Stress inflicted on horse is minimal, it compares to a intramuscular injection. The reliability of the system in use has so far been very high. Members of ISO have voted overwhelmingly in favor of a standard for electronic identification of animals. From now on, countries and user organizations can make use of this technique to identify animals and if used can rely on the fact t...
Neufang R.Comments are given on the present recommendations for the keeping of horses in stables. Proposals for an animal friendly accommodation are made including practical considerations.
Väihkönen LK, Pösö AR.To study in standardbred horses interindividual variation in the influx of lactate into red blood cells, venous blood samples were collected from 89 horses from 2 wk to 9 yr of age. For 62 horses, the rate of influx was normally distributed with a mean rate of 4.09 nmol.mg protein-1.min-1 at a lactate concentration of 10 mM, and the respective value for the other 27 horses was 0.58 nmol.mg protein-1.min-1. At 30 mM of lactate, the rates were 8.71 and 1.97 nmol.mg protein-1.min-1, respectively. This bimodal distribution was independent of age. In horses with high transport activity, the monocar...
Baptiste KE.The equine guttural pouch is a large, air-filled diverticulum of the auditory tube whose function is not clear. Since the horse does not possess a known, well-developed brain-cooling mechanism that could satisfy cerebral thermoregulatory demands, an hypothesis is proposed that respiratory air enters the guttural pouches, when needed, to ventilate and cool the internal carotid arteries (ICA). Experiments were initially carried out on nine cadavers, where blood flow was mimicked with warmed saline propelled by peristaltic pumps. Subsequent experiments were conducted on an anaesthetized horse whe...
Vandenput S, Votion D, Duvivier DH, Van Erck E, Anciaux N, Art T, Lekeux P.The aim of this study was to evaluate the respiratory function of horses affected with chronic obstructive pulmonary disease (COPD) when maintained in a barn on wood shavings and fed grass silage for a period of 6 weeks. The mechanics of breathing, blood gas analysis and bronchial reactivity were examined on five horses with COPD at the end of the environment-controlled period (Period B) and the results compared with values obtained after 2 months at pasture (Period A) and after the onset of clinical signs of acute crisis (Period C). The results showed that clinical and functional parameters w...
Weiss DJ, Evanson OA, Fagliari JJ, Valberg S.To determine whether platelets become activated and form platelet-neutrophil aggregates during near-maximal treadmill exercise in horses. Methods: 4 Thoroughbreds. Methods: Horses were subjected to 4 standardized exercise tests on a treadmill, and blood samples were collected before exercise, at treadmill speed of 12 m/s, and 5 minutes after exercise. Flow cytometric techniques were used to identify activated platelets, and flow cytometric and microscopic techniques were used to identify platelet-neutrophil aggregates. Results: Platelet-neutrophil aggregates increased from 2.8 +/- 0.4% at rest...
Guthrie AJ, Lund RJ.Metabolic HP is extremely high during exercise in horses. Thermoregulation in horses is primarily dependent on evaporative heat loss from sweating in particular. Under thermoneutral conditions, these mechanisms are sufficient to allow horses to perform high-intensity exercise for long periods. Under thermally stressful conditions, particularly in high ambient humidity, the efficiency of evaporative heat loss mechanisms is compromised and may result in horses developing hyperthermia. Early recognition and vigorous treatment are essential to limit the consequences of heat stress in horses. Metic...
Green J, Xie S, Gan X, Roberts RM.This manuscript describes the cloning of a novel aspartic proteinase expressed in the placenta of the horse (order Perrisodactyla). Evidence for similar genes in the cat (Carnivora) and ruminants (Artiodactyla), indicates that these molecules have been conserved within widely divergent species with distinct types of placentation. Since ePAG is produced by the outer cell layer (trophoblast) of the placenta, it can tentatively be grouped with the pregnancy-associated glycoproteins (PAG) of cattle, sheep, and pig. The high sequence identity that ePAG shares with pepsinogens as well as the PAG, in...
Kingston JK, Bayly WM.Exercise in horses is associated with a wide variety of physiological changes in fluid, electrolyte and acid base balance. The integration of physiologic and physiochemical mechanisms acts to minimize alterations in pH and enhance removal of carbon dioxide produced by exercising muscles. This article provides a description of the changes that take place during exercise and how these changes affect acid-base balance in the horse.
Hyyppä S, Pösö AR.During both high-intensity and short-distance exercise, the high rate of expended energy is met by anaerobic oxidation of glucose to lactic acid; this is the main cause of metabolic acidosis observed during racing. In addition, plasma volume decreases because water moves from the vasculature to the intracellular and interstitial spaces at the onset of intense exercise. These fluid shifts, together with active ion-exchange between blood and tissue, cause marked changes in electrolyte concentrations. This article reviews the mechanisms of acid-base disturbances, fluid shifts, and electrolyte cha...
Johnson PJ.This article presents a brief overview of the physiology of homeostasis in the horse and discusses the units of measurement by which dissolved electrolytes are assessed. Differences in electrolyte composition between compartments of the body and the manner in which water is exchanged between them are reviewed. The mechanisms by which alterations in osmolality and effective circulating volume are detected and the physiological responses to those alterations are presented.
Caetano AR, Bowling AT.Insulin-like growth factor 1 (IGF1) regulates growth and metabolic functions in vertebrates. A dinucleotide repeat sequence located at the promoter region of the IGF1 gene has been reported in several vertebrate species and may affect the control of the transcriptional activity of this gene. The genotypes of animals from seven horse breeds were determined in order to study the potential association of allelic forms of this microsatellite with adult body size differences found in domestic horses. Among these breeds, five alleles were found. Breed-specific differences in adult body size could no...
Brinsko SP, Squires EL, Pickett BW, Nett TM.The objective of this study was to determine if prolonged pulsatile administration of homologous gonadotropin-releasing hormone (GnRH) at therapeutic or 5x therapeutic doses would cause down-regulation of the stallion's hypothalamic-pituitary-testicular axis. Fifteen stallions were randomly assigned to three treatment groups (n=5/group) and received a 0.5 ml subcutaneous dose of saline (group 1), 50 microg GnRH (group 2), or 250 microg GnRH (group 3) every 2 hours for 75 days. Weekly evaluations of follicle stimulating hormone, luteinizing hormone, and testosterone and monthly evaluations of d...
Lennard SN, Gerstenberg C, Allen WR, Stewart F.Northern blot and in situ hybridization techniques have demonstrated a marked increase in mRNA encoding epidermal growth factor (EGF) in the endometrium of mares, coincident with the start of interdigitation between the allantochorion and endometrium during placentation. In the present study, the unusually high EGF expression in the epithelium of the endometrial glands was shown to be maintained until at least day 250 of gestation (term = 320-340 days) in mares carrying normal horse conceptuses. However, in mares carrying failing donkey-in-horse pregnancies created by embryo transfer, EGF expr...
Rahmanian MS, Thompson DL, Melrose PA.Gonadotropin-specific primary antisera and gold-conjugated secondary antibodies were used to immunocytochemically localize gonadotropins in the anterior pituitary of intact pony mares. Electron microscopy was then used to characterize the ultrastructure and immunoreactive staining characteristics of equine gonadotropes. Cells containing LH were morphologically indistinguishable from those containing FSH. Gonadotropes were relatively large and commonly had eccentric nuclei. The rough endoplasmic reticulum was well developed and dilated. Secretory granules were present in two morphologically dis...
Parlevliet JM.The studies described in this thesis investigated the factors that can affect the fertility of stallions. The introduction describes the male gamete and the processes that occur during maturation of sperm and fertilization. Methods to evaluate the quality of sperm and ova are then discussed. Fertility can be expressed in various ways and is also affected by many factors such as the stallion, the mare and management factors. The fertility of stallions is usually assessed a good year after they have served mares, because then the number of foals is known. However, it would be preferable to be ab...
Haouz A, Glandieres JM, Zentz C, Pin S, Ramstein J, Tauc P, Brochon JC, Alpert B.The effects of the solvent conditions (buffer pH 9, 8, or 7 or buffer pH 6.5 alone or mixed with 3.2% ethanol or 6.2% formamide) on the protein dynamics of horse apomyoglobin were investigated through tryptophan fluorescence quenching, spectra, and decay properties. Raising the pH (which induces discontinuous protein conformation changes) increases the structural fluctuations inside the hydrophobic A, G, and H helix core. Mixed solutions containing either 3.2% ethanol or 6.2% formamide (which redistribute water molecules on the protein surface) produce protein dynamics changes in the vicinity ...
Siedek E, Little S, Mayall S, Edington N, Hamblin A.Despite their important role in initiating T-cell responses in other species, dendritic cells have not been studied in the horse. A method for isolating blood dendritic cells by adherence and metrizamide gradients was adapted to equine cells. A number of monoclonal antibodies (mAbs), including some which label dendritic cells in other species, were tested for immunochemical reactivity with the isolated blood dendritic cells, and sections of lymph node and spleen. 62 +/- 6% of the isolated blood cells were MHC Class II positive and had typical dendritic cell morphology and only 4 +/- 2% contain...
Ludewig T.Corpora amylacea are present in all the mammary glands of the investigated animals (ewe, goat, and mares). Generally, they are comparable to the cow regarding to its distribution, frequency, size, morphological structure, and staining properties. Corpora amylacea occur most frequently in the ewe, and in non-lactating mammary glands. In lactating mammary glands they are mostly situated in the alveoles. During gestation they are located outside of the alveoles and in the interalveolar connective tissue. Only in very few cases corpora amylacea are found inside and outside of the alveoles in the s...
Viljanto M, Hincks P, Hillyer L, Cawley A, Suann C, Noble G, Walker CJ, Parkin MC, Kicman AT, Scarth J.The use of testosterone and its pro-drugs, such as dehydroepiandrosterone (DHEA), is currently regulated in horseracing by the application of international testosterone thresholds. However, additional steroidomic approaches, such as steroid ratios, to distinguish overall adrenal stimulation from drug administrations and an equine biological passport for longitudinal steroid profiling of individual animals could be advantageous in equine doping testing. Thus, DHEA concentrations and related ratios (testosterone [T] to DHEA and DHEA to epitestosterone [E]) were assessed in the reference populati...
Viklund Å, Furre S, Eriksson S, Vangen O, Philipsson J.Breeding programmes for warmblood sport horses are similar in the Nordic countries Sweden, Denmark, Finland and Norway, and stallions of same origin are used. The aim was to investigate whether a joint Nordic genetic evaluation based on lifetime competition performance is feasible and beneficial for breeding competitive sport horses in the Nordic countries. Results for almost 45,000 horses in show jumping and 30,000 horses in dressage were available. The larger populations in Sweden and Denmark contributed with 85% of the results. Heritabilities and genetic correlations between performances in...
Hancke J, Burgos R, Cáceres D, Brunetti F, Durigon A, Wikman G.Sport horses with long lasting high levels of gamma Glutamiltransferase (gGT) and Glutamic Oxalacetic Transaminase (GOT) and Creatinine Phosphokinase (CPK) and poor performance were administered during 14 days 3 g of Caval D'Or®, a standardized dried extract of Schizandra chinensis (fructus) orally. At day "0" the horses were divided into two groups: group 1 received a placebo and group 2 received Caval D'Or®. The results showed that Caval D'Or® is able to reduce significantly the levels of gGT and GOT in the serum at day 7 and 14 after administration. The CPK levels were also reduced by da...
Reyner CL, Winter RL, Maneval KL, Boone LH, Wooldridge AA.To investigate the effects of recombinant equine IL-1β on function of equine endothelial colony-forming cells (ECFCs) in vitro. Methods: ECFCs derived from peripheral blood samples of 3 healthy adult geldings. Methods: Function testing was performed to assess in vitro wound healing, tubule formation, cell adhesion, and uptake of 1,1'-dioctadecyl-3,3,3',3' tetramethylindocarbocyanine perchlorate-labeled acetylated low-density lipoprotein (DiI-Ac-LDL) by cultured ECFCs. Cell proliferation was determined by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide assay. Effects o...
McKinney AR, Suann CJ, Dunstan AJ, Mulley SL, Ridley DD, Stenhouse AM.The equine phase I and phase II metabolism of the synthetic anabolic steroid stanozolol was investigated following its administration by intramuscular injection to a thoroughbred gelding. The major phase I biotransformations were hydroxylation at C16 and one other site, while phase II metabolism in the form of sulfate and beta-glucuronide conjugation was extensive. An analytical procedure was developed for the detection of stanozolol and its metabolites in equine urine using solid phase extraction, acid solvolysis of phase II conjugates and analysis by positive ion electrospray ionization ion ...
Cherry RL, Adair HS, Chen T, Hendrix DVH, Ward DA.Spontaneous eyeblink rate (SEBR) is inversely proportional to the level of attentional focus in humans. The objective of this study was to evaluate the effects of attentional focus on SEBR in horses. Methods: Twenty client-owned horses (2.5-23 years of age, five mares, 15 geldings) were evaluated. A GoPro HERO5 Session™ video recorder was attached to the halter and directed toward the eyes. Horses were acclimated for two hours before study commencement. Horses were filmed in five scenarios requiring different levels of attention: alone in a stall ("stall"), stall with an observer ("person")...
Runcan EE, Pozor MA, Zambrano GL, Benson S, Macpherson ML.The acrosome is a highly specialised region of the spermatozoon that is essential for fertilisation. Defects or dysfunction of this structure have been associated with fertility problems in man and various domestic species including stallions. Current methods of evaluating the acrosome of stallion spermatozoa are time consuming and require specialised equipment, which is cost prohibitive to the average practitioner. Objective: To evaluate 2 conventional stains (Dip Quick and Spermac) and determine their usefulness in assessing acrosome integrity in stallions as compared with specific acrosomal...
McFarlane JR, Czekala NM, Papkoff H.Six samples of pregnant zebra (z) serum from the first and second trimesters of pregnancy were analyzed by RIA and shown to have chorionic gonadotropin levels comparable to that of the mare (0.9-5.3 micrograms/ml); first trimester levels in most cases were higher than second trimester levels. A pool of the sera (10 ml) was fractionated by methods previously employed for the purification of equine (e) and donkey (d) chorionic gonadotropin to achieve a concentration of the zebra chorionic gonadotropin (zCG). A yield of 1.0 mg of glycoprotein was obtained. HPLC analysis of the material indicated ...
Vaughn DM, Smyth GB, Whitmer WL, Satjawatcharaphong C.Small volumes (0.05 ml) of cisterna magna cerebrospinal fluid (CSF) from 23 neurologically normal horses were analysed for the monoamine neurotransmitters dopamine, norepinephrine, epinephrine, serotonin and their metabolites using high pressure liquid chromatography and electrochemical detection. Two metabolites, homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) were present in all CSF samples. The deaminated and methylated metabolite of dopamine, HVA, was present at a mean concentration of 42.33 +/- 3.14 ng/ml of CSF. The deaminated metabolite of serotonin, 5-HIAA, was present ...
Tofé E, Muñoz A, Castejón F, Trigo P, Castejón-Riber C, Gómez-Díez M, Riber C.The influence of hydration prior to exercise on hormonal response to exercise was investigated in horses, divided into two groups, control (n=11) and dehydrated (n=53). They were also classified according to their body weight in A (≈ 350 kg), B (351-450 kg) and C (≈ 451 kg). Horses covered 60 m on a track pulling a carriage loaded with 2, 2.25 and 2.5 times their body weight, for A, B and C. Blood samples were taken at rest, after exercise and during recovery. Electrolytes, albumin, renin, angiotensin and aldosterone concentrations were measured. Dehydrated and control horses had higher al...
Pérez-Marín CC, Vizuete G, Vazquez-Martinez R, Galisteo JJ.Few studies have been published about cryopreservation and embryo assessment in horses and donkeys. Objective: To evaluate the viability of embryos collected from mares and jennies that were cryopreserved by slow freezing or by vitrification. Methods: Randomised controlled experiment. Methods: Horse (n=19) and donkey (n=16) embryos (≤300 μm) were recovered on days 6.5-7.5 post-ovulation and assigned to control or cryopreservation protocols of slow freezing or vitrification. For slow freezing, 1.5 mol/L ethylene glycol (EG) was used. For vitrification, horse embryos were exposed to 1.4 mol/L...
Fitzgerald BP, Affleck KJ, Barrows SP, Murdoch WL, Barker KB, Loy RG.Two groups of mares were exposed to an abrupt, artificial increase or a natural increase in daylength. In both groups, mean LH pulse frequency increased with time of year and was accompanied by a reciprocal decrease in LH pulse amplitude. A non-pulsatile pattern of LH secretion was observed in some mares sampled close to the day of ovulation. Maximum mean LH pulse frequency and the onset of the breeding season occurred earlier in those mares exposed to an abrupt artificial increase in daylength. In blood samples collected frequently, mean serum LH concentrations increased in relation to time o...
Franklin SH, Barakzai SZ, Couroucé-Malblanc A, Dixon P, Nankervis KJ, Perkins JD, Roberts CA, Vanerck-Westergren E, Allen KJ.During the past 20 years, treadmill exercise testing has played an important role in both the study of equine exercise physiology and the investigation of poor athletic performance. However, it has been suggested that some trainers and veterinarians may be reluctant to refer horses for treadmill exercise testing because of fears that horses may be at increased risk of musculoskeletal injury during treadmill exercise. Objective: To investigate the incidence and types of injuries sustained by horses undergoing treadmill exercise. Methods: Data were collated from 9 centres in the UK, France and B...
Carmalt JL, Allen AL.To evaluate the effect of rostrocaudal mobility (RCM) of the mandible during extension and flexion of the atlanto-occipital joint on weight gain, feed digestibility, and fecal particle size in horses. Methods: Randomized controlled trial. Methods: 34 pregnant mares housed in 1 barn. Methods: Horses were randomized into a treatment (n = 17) or control (17) group. All horses were sedated, and the distance between the rostral portions of the upper and lower incisor arcades was determined during extension and flexion of the atlanto-occipital joint; mandibular RCM was calculated as the difference b...
Tremaine H.The last decade has seen a number of studies that have illuminated our knowledge of hypsodont dental disease and re-examined some of the traditionally performed practices. In addition there has been a major interest in routine preventative dentistry and non-traumatic treatments. These have highlighted some potential risks of the use of modern tools when applied to traditional techniques. This has also led to a reflective review of equine dentistry with the emphasis on attempting to preserve and salvage dental and periodontal tissues, with minimal trauma. In addition, precise imaging and instru...
Engle CE, Foley CW, Witherspoon DM, Scarth RD, Goetsch DD.Three experiments were conducted on the metabolism of stallion sperm. In experiment 1, whole and washed sperm were incubated under aerobic and anaerobic enviroments and analyzed before and after controlled incubation for motility, pH, lactic acid, glucose, fructose, and O2 comsumption. In experiment 2, whole and washed sperm were incubated aerobically and anaerobically with and without uterine tubal fluids. Experiment 3 was the same as experiment 2, except added substrates of glucose and lactic acid were studied. The same examinations were made in experiments 2 and 3 as for experiment 1. Motil...
Chevalier F, Palmer E.Ultrasonic echography in the mare allows pregnancy diagnosis as early as Day 14 after ovulation. In the 1980 and 1981 breeding seasons, a total of 7438 examinations of 4688 mares were performed on several farms with the same apparatus. The accuracy of positive pregnancy diagnosis was estimated to be greater than 95% and of non-pregnancy diagnosis greater than 84%. When abnormal pictures of vesicles are found, it has to be decided whether it is a conceptus or a cystic structure. Most small vesicles do not develop, whereas large ones, deformed shapes, presence of some echoes, or a division insid...
Makowiecki D, Chudziak W, Szczepanik P, Janeczek M, Pasicka E.Knowledge about horses from early medieval (10th-13th c.) Poland has been largely based on historical and archaeological data. Archaeozoological information has only been used to a limited extent. Therefore, this article aims to present the current state of knowledge on this subject, drawing on archaeozoological data from studies of horse bones. Apart from confirming earlier reflections regarding the sacred significance of the horse, additional information was obtained about specific individuals who were the subject of magical treatments. It turned out that sites with horse skeletons and skull...
Takahashi Y, Takahashi T, Mukai K, Ebisuda Y, Ohmura H.Given that Thoroughbred horses' canter is an asymmetric gait, not only speed but also leading or trailing limbs could affect muscle activities. However, the muscle activity during a canter remains poorly understood. Hence, we aimed to investigate speed and lead-side (leading or trailing) effects on surface electromyography (sEMG) during a canter. The sEMG data were recorded from left Musculus brachiocephalicus (Br), M. infraspinatus (Inf), long head of M. triceps brachii (TB), M. gluteus medius (GM), M. semitendinosus (ST), and M. flexor digitorum longus of seven Thoroughbreds with hoof-strain...
Sales FABM, Azevedo MV, Souza NM, Ferreira-Silva JC, Chaves MS, Junior VR, Rocha JM, Dos Santos Filho JP, Freitas VJF, Oliveira MAL.The aim of this study was to evaluate the correlation between the corpus luteum vascularization with the concentration of progesterone and the fertility of embryo recipient mares. Mangalarga Marchador mares (n = 33) were distributed into groups according to the days (D) after ovulation, as follows: D3 (n = 8), D4 (n = 8), D5 (n = 9), and D6 (n = 8). The evaluations of the corpus luteum, endometrium, and blood collection to quantify the progesterone concentration were carried out on D3, D4, D5, and D6. Among the parameters evaluated, only progesterone concentration on D6 differed from the other...
Earley ET, Reiswig JD.Odontoplasty (floating and occlusal equilibration) is the most commonly performed procedure in equine dentistry. From an anatomic perspective, an irregular occlusal surface, prominent cingula, transverse ridges, and enamel points all contribute to the function, form, and longevity of the equine cheek tooth. With limited reserve crown available and an average functional life range between 18 and 25 years, removal of tooth structure should be conservative. The authors consider a quality oral examination to be the most important dental procedure performed in the horse. Individual tooth evaluatio...
Allen ML, Baker GJ, Freeman DE, Holmes KR, Marretta SM, Scoggins RD, Constable P.To measure the amount of heat generated during 3 methods of equine dental reduction with power instruments. Methods: In vitro study. Methods: 30 premolar and molar teeth removed from mandibles of 8 equine heads collected at an abbatoir. Methods: 38-gauge copper-constantan thermocouples were inserted into the lingual side of each tooth 15 mm (proximal) and 25 mm (distal) from the occlusal surface, at a depth of 5 mm, which placed the tip close to the pulp chamber. Group-NC1 (n = 10) teeth were ground for 1 minute without coolant, group-NC2 (10) teeth were ground for 2 minutes without coolant, a...
Kirkpatrick JF, Liu IM, Turner JW, Bernoco M.Twenty-six free-roaming feral mares were immunized against porcine zonae pellucidae (PZP) between February and May, 1988. Eight sexually mature mares received 2 inoculations 2 weeks apart, and 18 mares received 3 inoculations at intervals of 2 and 4 weeks. Analysis of urinary oestrone conjugates (E1C) and non-specific progesterone metabolites (iPdG) in samples collected in October, 1988, revealed that none of the 18 mares that received 3 and only 1 of the 6 mares that received two inoculations were pregnant, whereas 3 of 6 sham-injected control mares and 5 of 11 untreated mares were pregnant. ...
Ward A, Stephen K, Argo C, Watson C, Harris P, Neacsu M, Russell W, Grove-White D, Morrison P.During the lockdown phase of the COVID-19 pandemic, equestrian stakeholders faced a dilemma whereby they were required to balance caring for the welfare of horses with adapting to the restrictions imposed to protect public health. The present study investigated the impact of the pandemic on the wellbeing of a sample of industry stakeholders, including horse owners, equine veterinarians, farriers and welfare centre managers ( = 26) using a qualitative methodology. Findings from the interviews indicated that the mental health and wellbeing of veterinarians and horse owners was negatively affecte...
De Silva M, Tagliavia C, Galiazzo G, Gifuni G, Caiazza M, Chiocchetti R, Grandis A.The morphometric studies of the atrioventricular valves are still limited in the horse. Objective: To investigate the anatomy of the atrioventricular valves in the horse, focusing on the morphometric features of the valvular leaflets and the tendinous cords. We hypothesised that accessory leaflets occur commonly and exist as independent structures in the atrioventricular valves of the horse. Methods: Descriptive anatomical study. Methods: Twenty normal hearts from slaughtered half-bred horses were used. The cardiac weight and circumference were recorded. The atrioventricular valves were expose...
Hyland JH, Wright PJ, Clarke IJ, Carson RS, Langsford DA, Jeffcott LB.In Exp. 1, 30 Standardbred mares in deep seasonal anoestrus were divided into 3 equal groups and treated with 0, 50 (G50) or 100 (G100) ng GnRH kg-1h-1 for 28 days via osmotic minipumps. Ovulation occurred in 0/10, 3/10 and 7/10 mares respectively (P less than 0.05). Plasma GnRH profiles (Days -6, 0, 2, 6, 12, 20, 28 and 34 relative to pump insertion) were dose-dependent (P less than 0.01) and peaked on Day 12 of infusion. Mean daily plasma LH concentrations were biphasic in treated mares that ovulated, with LH peaks occurring around Day 6 and Days 16-20. By contrast, in treated mares that did...
Desmadril M, Mitraki A, Betton JM, Yon JM.The unfolding-folding transition of phosphoglycerate kinase induced by GuHC1 was studied at equilibrium. Various signals were used to follow the transition: fluorescence emission, difference spectra, circular dichroism and enzymatic activity. The non-coincidence of transition curves obtained from different structural parameters indicate a deviation from a two-state process. The view that structural domains behave as independent "folding units" is critically discussed.
Montgomery I, Jenkinson DM, Elder HY.Sweating in the horse had little effect on the ultrastructure of the glandular duct, other than on the lumen which enlarged. The fundus secretory cells, which in the resting gland were packed with vesicles, gradually lost them as sweating progressed until, after 4 hours of activity, few remained. Sweat appeared to be largely the product of secretion (a) by fluid transport, probably involving a region of complex cellular interdigitations adjacent to the basement membrane and (b) by exocytosis of vesicles, although a secondary mechanism of vesicle loss by micro-apocrine secretion may occur. Howe...
Rueca F, Conti MB, Porciello F, Spaterna A, Antognoni MT, Mangili V, Fruganti G, Avellini G.The purpose of this study was to assess the possible relationship between maximal running speed, serum isoenzyme patterns of creatine kinase (CK) and lactate dehydrogenase (LDH) and echocardiographic indices of left ventricular function. A group of 15 healthy, 3-year-old Maremmano stallions were given a 100 day training programme. At the end of this the animals carried out a maximum speed test and were divided into 2 groups (A and B) according to whether or not they had attained a speed of 15 m/s. Venous blood samples were taken from each horse before exercise (T0), 2 min (T1) and 24 h (T2) af...
Ralston SL, Baile CA.Ponies are large nonruminant herbivores which are capable of utilizing the products of both enzymatic digestion in the small intestine and bacterial fermentation (volatile fatty acids, VFAs) in the cecum and large colon as sources of metabolizable energy. Recent studies have demonstrated that ponies utilize nutrient stimuli from both carbohydrate and fat digestion in the small intestine and VFAs in the cecum and large colon in the control of meal frequency. These animals, however, rely primarily upon oropharyngeal and external stimuli to control the size and duration of meals. This is perhaps ...
