The physiology of horses encompasses the study of the biological functions and processes that occur within the equine body. This includes the examination of various systems such as the cardiovascular, respiratory, musculoskeletal, digestive, and nervous systems. Understanding equine physiology is essential for comprehending how horses adapt to different environmental conditions, perform physical activities, and respond to health challenges. Research in this field often focuses on the mechanisms of energy metabolism, thermoregulation, and muscle function during exercise, as well as the physiological responses to stress and disease. This page compiles peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine physiology, providing insights into the biological processes that support the health and performance of horses.
Maeda Y, Oikawa MA.Shipping Fever is a transport associated syndrome seen in equids and bovines transported during long distances. The microbial profile and clinical signs vary between species, and in horses it is characterized by pharyngeal commensal bacteria and aerosolized particulate matter invading the lower airway due to compromised mucocillary clearance mechanisms during transports. This leads to pyrexia, pulmonary parenchymal disease, inappetence, and in severe cases pleuropneumonia. It has been shown that the incidence of transport-related pyrexia in horses increases with travel time and distance, howev...
Van Steenkiste G, De Clercq D, Vera L, Decloedt A, van Loon G.Atrial tachycardia including focal atrial tachycardia and macroreentrant atrial tachycardia (atrial flutter), are occasionally found in horses. Diagnosis, treatment and follow-up of these arrhythmias has been inadequately described. Objective: To describe the findings on surface electrocardiography (ECG), intra-atrial electrogram recording and tissue Doppler imaging (TDI), the response to treatment by transvenous electrical cardioversion (TVEC), and TDI follow-up, of sustained atrial tachycardia in horses. Methods: Case series. Methods: Records from horses with sustained atrial tachycardia tre...
Steppacher I, Kissler J.There is a growing number of children surviving birth complications with severe, multiple disabilities. Unfortunately, this is not paralleled by equal growth in knowledge about adequate therapeutic approaches. Some publications showed that Hippotherapy could, under certain circumstances, be a very useful complimentary therapy for a range of disabilities. But it remains unclear if riding could even help a quadriplegic individual with multiple brain damage and tracheal ventilation. Methods: In this case study we examined the effect of horse riding on the mobility of joints and heart rate in a li...
Nolazco Sassot L, Villarino NF, Dasgupta N, Morrison JJ, Bayly WM, Gang D, Sanz MG.A comprehensive study of the effect of supramaximal exercise in lipid homeostasis of Thoroughbreds provides the basis for future research on the role of lipids on energy metabolism in racehorses. Objective: To compare the plasma lipidome of Thoroughbreds before and after supramaximal exercise using an untargeted lipidomics approach. Methods: Pilot experimental study. Methods: Four Thoroughbred horses were used. The maximal oxygen consumption (VO ) was calculated for each horse. Horses then underwent treadmill exercise at the speed for which the oxygen requirements had been calculated to be 11...
Stokes SM, Belknap JK, Engiles JB, Stefanovski D, Bertin FR, Medina-Torres CE, Horn R, van Eps AW.Continuous digital hypothermia can prevent the development and progression of laminitis associated with sepsis but its effects on laminitis due to hyperinsulinaemia are unknown. Objective: To determine the effects of continuous digital hypothermia on laminitis development in the euglycaemic hyperinsulinaemic clamp model. Methods: Randomised, controlled (within subject), blinded, experiment. Methods: Eight clinically normal Standardbred horses underwent laminitis induction using the euglycaemic hyperinsulinaemic clamp model (EHC). At initiation of the EHC, one forelimb was continuously cooled (...
Contreras-Aguilar MD, Martínez-Subiela S, Cerón JJ, Martín-Cuervo M, Tecles F, Escribano D.Salivary biomarkers could be useful to objectively evaluate critical illness and prognosis for survival in horses with acute abdominal disease. Objective: To compare salivary alpha-amylase (sAA) activity and concentration in healthy horses and horses with acute abdominal disease, and evaluate the association between sAA activity and concentration with disease severity and outcome. Methods: A prospective cohort. Methods: sAA activity, measured using a colorimetric commercial kit, and concentration, measured using a Time-resolved immunofluorometric assay, in 25 healthy horses and in 33 horses wi...
Witkowska-Piłaszewicz OD, Żmigrodzka M, Winnicka A, Miśkiewicz A, Strzelec K, Cywińska A.Serum amyloid A (SAA) is the major acute phase protein in horses. It is produced during the acute phase response (APR), a nonspecific systemic reaction to any type of tissue injury. In the blood of healthy horses, SAA concentration is very low, but it increases dramatically with inflammation. Due to the short half-life of SAA, changes in its concentration in blood closely reflect the onset of inflammation and, therefore, measurement of SAA useful in the diagnosis and monitoring of disease and response to treatment. Increases in SAA concentration have been described in equine digestive, reprodu...
O'Neil MM, Korthanke CM, Scarpa JO, Welsh TH, Cardoso RC, Williams GL.We tested the hypotheses that in winter anovulatory mares (1) both chronic daily injections of estradiol-17β (E2) and subcutaneous E2 implants could enhance pituitary secretion of gonadotropins in response to continuous subcutaneous infusion of native gonadotropin-releasing hormone (GnRH); and (2) the secretory pattern of follicle-stimulating hormone (FSH) in response to continuous subcutaneous infusion of native GnRH is similar to that of luteinizing hormone (LH) but differs between mares that develop or fail to develop an estrogen-active, preovulatory follicle. In Experiment 1, 20 winter an...
Vafaei F, Kohram H, Zareh-Shahne A, Ahmad E, Seifi-Jamadi A.This study was aimed to evaluate the effect of permeable cryoprotectants in combination with trehalose or sucrose on the freezing capacity of stallion sperm. For this purpose, the ejaculates (n = 24) were collected from four healthy mature Turkmen stallions. The ejaculates were pooled and diluted with one of the extenders containing a combination of 5% of permeating (dimethylacetamide [DMA]; dimethylformamide [DMF] or glycerol) and 50 mM of nonpermeating cryoprotectant agents (CPAs) (sucrose or trehalose) to a final concentration of 200 × 10 spermatozoa/mL. The extended samples were cryopr...
Manning HS, Runcan EE, Dias de Moraes CR, Coutinho da Silva MA.The objective of this study was to use estrous behavior alone to determine the appropriate time for beginning an oxytocin treatment protocol for estrus suppression. We hypothesized that administration of oxytocin beginning 8 days after the onset of estrus will prolong the luteal phase in mares. Twenty-three light breed mares (aged 4-20 years) were exposed to a stallion and observed for signs of sexual receptivity. Mares not displaying signs received 250 μg of cloprostenol intramuscularly (IM) and were teased again 3-4 days later. On the day that estrous behavior was observed (Day 0), mare...
Cuervo-Arango J, Claes AN, Beitsma M, Stout TAE.The in vitro production of embryos by ovum pickup (OPU) and intracytoplasmic sperm injection (ICSI) is gaining popularity among horse breeders and veterinarians. Various collection media are available for flushing follicles during OPU. The objective of this study was to determine whether the type of flushing media used to aspirate follicles and collect oocytes influences the outcome of a commercial equine OPU-ICSI program. Two commercial embryo flushing media (EFM1 and EFM2) supplemented with heparin were compared with a flushing media designed specifically for the collection of oocytes (oocy...
Consuegra C, Crespo F, Dorado J, Diaz-Jimenez M, Pereira B, Ortiz I, Arenas R, Morrell JM, Hidalgo M.Stallion sperm was vitrified using straws in comparison with spheres and conventional freezing. Vitrification was performed plunging 30 μL of sperm (spheres) or 0.5 mL straws into liquid nitrogen (LN) and conventional freezing using 0.5 mL straws frozen in LN vapors. Sperm vitrified in straws were submitted to different warming procedures (42°C/20 seconds; 60°C/15 seconds) and single-layer centrifugation (SLC). Total (TM, %) and progressive sperm motility (PM, %), plasma membrane (IMS, %) and acrosome integrity (AIS, %) were statistically compared between treatments (mean ± SEM). Signif...
Leemans B, Stout TAE, De Schauwer C, Heras S, Nelis H, Hoogewijs M, Van Soom A, Gadella BM.In contrast to various other mammalian species, conventional in vitro fertilization (IVF) with horse gametes is not reliably successful. In particular, stallion spermatozoa fails to penetrate the zona pellucida, most likely due to incomplete activation of stallion spermatozoa (capacitation) under in vitro conditions. In other mammalian species, specific capacitation triggers have been described; unfortunately, none of these is able to induce full capacitation in stallion spermatozoa. Nevertheless, knowledge of capacitation pathways and their molecular triggers might improve our understanding o...
Valberg SJ, Soave K, Williams ZJ, Perumbakkam S, Schott M, Finno CJ, Petersen JL, Fenger C, Autry JM, Thomas DD.Sarcolipin (SLN), myoregulin (MRLN), and dwarf open reading frame (DWORF) are transmembrane regulators of the sarcoplasmic reticulum calcium transporting ATPase (SERCA) that we hypothesized played a role in recurrent exertional rhabdomyolysis (RER). Objective: Compare coding sequences of SLN, MRLN, DWORF across species and between RER and control horses. Compare expression of muscle Ca2+ regulatory genes between RER and control horses. Methods: Twenty Thoroughbreds (TB), 5 Standardbreds (STD), 6 Quarter Horses (QH) with RER and 39 breed-matched controls. Methods: Sanger sequencing of SERCA reg...
Davern AJ, Peloso JG, Hawkins JF, Moore GE, Morehead JP.OBJECTIVE To evaluate 2- and 3-year-old and career race performance of Thoroughbred racehorse prospects with and without osteochondral fragmentation of the accessory carpal bone (ACB) identified on yearling presale radiographs. DESIGN Retrospective, matched cohort study. ANIMALS 47 nonlame Thoroughbreds with (exposed cohort) and 94 nonlame Thoroughbreds without (unexposed cohort) osteochondral fragmentation of ACB facture identified on yearling sales repository radiographs. PROCEDURES Repository radiographic interpretation reports for September yearling sales of a large Kentucky auction house ...
Olivier A, Viseu JP, Vignais N, Vuillerme N.Horseback riding requires the ability to adapt to changes in balance conditions, to maintain equilibrium on the horse and to prevent falls. Postural adaptation involves specific sensorimotor processes integrating visual information and somesthesic information. The objective of this study was to examine this multisensorial integration on postural control, especially the use of visual and plantar information in static (stable) and dynamic (unstable) postures, among a group of expert horse rider women (n = 10) and a group of non-athlete women (n = 12). Postural control was evaluated through the c...
Melchert M, Aurich C, Aurich J, Gautier C, Nagel C.Mares usually give birth when they perceive their environment as safe and therefore disturbance at foaling may inhibit labor. In this study, foaling mares were transferred to an unfamiliar environment at rupture of the allantochorion (stress, n = 6) or were left undisturbed (control, n = 5). The progress of foaling, heart rate, heart rate variability (HRV) and plasma catecholamine, oxytocin and cortisol concentration were determined. In stressed mares, time from rupture of the allantochorion to appearance of the fetal feet (5.3 ± 1.1 vs. 1.6 ± 0.4 min) and total length of f...
Velie BD, Lillie M, Fegraeus KJ, Rosengren MK, Solé M, Wiklund M, Ihler CF, Strand E, Lindgren G.Horses have been strongly selected for speed, strength, and endurance-exercise traits since the onset of domestication. As a result, highly specialized horse breeds have developed with many modern horse breeds often representing closed populations with high phenotypic and genetic uniformity. However, a great deal of variation still exists between breeds, making the horse particularly well suited for genetic studies of athleticism. To identify genomic regions associated with athleticism as it pertains to trotting racing ability in the horse, the current study applies a pooled sequence analysis ...
Destrez A, Grimm P, Julliand V.The bidirectional communication between the central and the enteric nervous system named the gut-brain axis has been widely recognized. The gut microbiota has been implicated in a variety of stress-related conditions including anxiety, depression and irritable bowel syndrome based on rodent studies or correlative analysis in human patients. The aim of the present study was to investigate to what extent changes in behavior during stressful events and in the microbial composition of the colonic ecosystem were associated in horses. The microbiota alterations were induced by a change from a high-f...
Leisinger CA, Klein C, Markle ML, Premanandan C, Sones JL, Pinto CRF, Paccamonti DL.Aluteal cycles were induced in the mare to evaluate the effects of progesterone deprivation on the gene expression of embryos and endometrium collected eight days after ovulation. We hypothesized that the transcript expression would be altered during induced aluteal (AL) cycles (low progesterone <1 ng/mL) when compared with control cycles during diestrus (high progesterone; > 4 ng/mL) for 1) the embryonic expression of progesterone-mediated transcripts and those related to normal embryo growth and development and 2) the endometrial expression of progesterone-mediated transcripts and those ...
Berryhill EH, Magdesian KG, Tadros EM, Edman JE.Maintaining serum glucose concentrations is critical in neonatal foals and is often dysregulated in illness; however, few studies have assessed the effects of age, or variation of glucose and insulin, in neonates and their postpartum dams. This study aimed to serially evaluate serum glucose and insulin concentrations and glucose/insulin (G/I) ratios in seven healthy foals and their dams immediately postpartum and at 1-2 and 10-12days of age. The hypotheses were that: (1) there would be wide temporal variation in hourly glucose and insulin measurements among foals; and (2) measured parameters i...
Işık R.Lactoferrin (LTF), also called lactotransferrin, is an iron-binding protein and member of transferrin family, whereas β-LG is an important milk protein and belongs to the ligand-binding protein family of lipocalins and binds retinol. Beta-lactoglobulin (β-LG) is a major whey protein and it is a member of lipocalins family. β-LG is also known as a major allergen reason of cow milk protein allergy. Yet, no information has been reported about β-LG and LTF genes in donkeys. In this study, the genetic variation of β-LG and LTF genes were analyzed via DNA sequencing in 77 donkeys, which were in...
Bino E, Lauková A, Ščerbová J, Kubašová I, Kandričáková A, Strompfová V, Miltko R, Belzecki G.The intestinal microbiota has enormous impact on the health and performance of horses. Staphylococci belong in the phylum Firmicutes, and their occurrence, especially of methicillin-resistant strains and species, has been reported in horses previously. Moreover, biofilm formation is one of the virulence factors; it has been not completely studied in fecal coagulase-negative staphylococci (CoNS) from horses. Therefore, this study was focused on biofilm formation by various species of fecal CoNS from horses because it has been never reported before. In addition, their antibiotic profile was test...
Breuhaus BA.Glucocorticoids are known to exert inhibitory action on the hypothalamic-pituitary-thyroid axis. With recent evidence that free plasma cortisol and urinary excretion of cortisol metabolites may be increased in horses with pituitary pars intermedia dysfunction (PPID), it is important to further examine thyroid function in horses with PPID. To test the hypothesis that serum thyrotropin (TSH) concentrations are decreased in horses with PPID, baseline serum thyroid hormone and TSH concentrations, and responses to TSH-releasing hormone (TRH), were compared between 12 horses diagnosed as having PPID...
Pluháček J, Tučková V, King SRB, Šárová R.Overmarking occurs when one individual places its scent mark directly on top of the scent mark of another individual. Although it is almost ubiquitous among terrestrial mammals, we know little about the function of overmarking. In addition, almost all studies on mammalian overmarking behaviour dealt with adult individuals. Reports on this behaviour in juveniles are extremely rare, yet may elucidate the function of this behaviour. We tested four mutually non-exclusive hypotheses which might explain this behaviour in juveniles: (1) conceal the individual's scent identity, (2) announcement of ass...
Endo H, Nguyen ST, Yoshida M, Kudo K.The three-dimensionally real position and movement of the scapula in the lateral side of the ribcage could not be clarified in the horse, since the body size of the horse is too large to apply the CT scanning and image analysis methods. In this study, therefore, we examined the position and the movability of scapula using a carcass of the Falabella which is one of the smallest breeds of the horse. The whole skeletal system in thoracic part of the Falabella could be three-dimensionally observed by CT scanning method. The three-dimensional images show that the scapula cranially slides and the ve...
Rota A, Sabatini C, Przybył A, Ciaramelli A, Panzani D, Camillo F.To increase sperm motility, several molecules have been tested in mammals. Methylxanthines have shown effects on sperm motility, capacitation, and on in vitro fertilization processes. The aim of the study was to evaluate if the post-thaw addition of caffeine and/or pentoxifylline changes motility parameters of cryopreserved stallion and donkey spermatozoa. Straws derived from 14 horses and 7 donkeys were thawed and diluted in a milk-based extender to obtain the following final concentrations: CTR (control, no additives), CAF 5 (5 mM caffeine), CAF 10 (10 mM caffeine), PTX 5 (5 mM pentoxify...
Sarnecky BA, Vanderwall DK, Mason HM, Kirschner SM, Ambrose B, Parker TL.Prolonging function of the corpus luteum (CL) is a method of suppressing estrus that relies on continued secretion of endogenous progesterone to keep mares out of heat naturally. The use of oxytocin treatment to prolong CL function is gaining increasing use, and the most common treatment protocol involves administration of 60 units of oxytocin intramuscularly (IM) once daily on days 7-14 after ovulation (eight daily treatments). Although that protocol induces prolonged CL function in ≥70% of treated mares, the need for daily administration is a drawback to its use. Therefore, the objective o...
Medica P, Giunta RP, Bruschetta G, Ferlazzo AM.Exercise represents a physical stress that challenges homeostasis affecting central and peripheral serotoninergic systems. The influence of the exercise on circulating serotonin (5-hydroxytryptamine [5-HT]) levels depends on training state as well as the exercise protocol. The purpose of the present research was to determine changes of plasma 5-HT in sport horses in response to training (T) and simulated race (SR) and in addition to assess the possible presence of significant differences on circulating 5-HT between two different sessions of exercise. In particular, the research was carried out...
Linardi RL, Megee SO, Mainardi SR, Senoo M, Galantino-Homer HL.The limited characterization of equine skin, eye and hoof epithelial stem cell (ESC) and differentiation markers impedes the investigation of the physiology and pathophysiology of these tissues. Objective: To characterize ESC and differentiation marker expression in epithelial tissues of the equine eye, haired skin and hoof capsule. Methods: Indirect immunofluorescence microscopy and immunoblotting were used to detect expression and tissue localization of keratin (K) isoforms K3, K10, K14 and K124, the transcription factor p63 (a marker of ESCs) and phosphorylated p63 [pp63; a marker of ESC tr...
Stock SR, Deymier-Black AC, Veis A, Telser A, Lux E, Cai Z.Dentin contains 1-2μm diameter tubules extending from the pulp cavity to near the junction with enamel. Peritubular dentin (PTD) borders the tubule lumens and is surrounded by intertubular dentin (ITD). Differences in PTD and ITD composition and microstructure remain poorly understood. Here, a (∼200nm)(2), 10.1keV synchrotron X-ray beam maps X-ray fluorescence and X-ray diffraction simultaneously around tubules in 15-30μm thick bovine and equine specimens. Increased Ca fluorescence surrounding tubule lumens confirms that PTD is present, and the relative intensities in PTD and ITD correspon...
Hayden SS, Blanchard TL, Brinsko SP, Varner DD, Hinrichs K, Love CC.Dilution of semen to less than 20 × 10(6) sperm/mL has been reported to decrease sperm quality in multiple species, a phenomenon known as the semen "dilution effect." Critical evaluation of stallion semen diluted to these concentrations, however, has not been reported. This study evaluated sperm motion characteristics (percent total motility [TMOT], percent progressive motility [PMOT], curvilinear velocity [μm/s], and percent straightness) and plasma membrane integrity (percent plasma membrane intact [PMI]) in semen samples diluted to 2.5 × 10(6) sperm/mL with the addition of 0%, 7.5%, ...
Dunnett M, Harris RC, Dunnett CE, Harris PA.This study was undertaken as part of a larger investigation into carnosine metabolism and function in the Thoroughbred horse. More specifically, we wished to evaluate plasma carnosine concentration as a potential indicator of muscle carnosine status. In contrast to man, carnosine is present in equine plasma where its presence is consistent with the absence of plasma carnosinase. A significant effect of age on plasma carnosine concentration in resting Thoroughbred horses was observed. Values in horses age 3 years and older were 113-14.1 micromol/l, whereas concentrations in foals and yearlings ...
Marr N, Hopkinson M, Hibbert AP, Pitsillides AA, Thorpe CT.Three-dimensional imaging modalities for optically dense connective tissues such as tendons are limited and typically have a single imaging methodological endpoint. Here, we have developed a bimodal procedure utilising fluorescence-based confocal microscopy and x-ray micro-computed tomography for the imaging of adult tendons to visualise and analyse extracellular sub-structure and cellular composition in small and large animal species. Results: Using fluorescent immunolabelling and optical clearing, we visualised the expression of the novel cross-species marker of tendon basement membrane, lam...
Tharasanit T, Colleoni S, Lazzari G, Colenbrander B, Galli C, Stout TA.Oocyte cryopreservation is a potentially valuable way of preserving the female germ line. However, the developmental competence of cryopreserved oocytes is presently poor. This study investigated whether the morphology of the cumulus complex surrounding an immature equine oocyte and/or the oocyte's stage of maturation affect its cryopreservability. Compact (Cp) and expanded (Ex) cumulus oocyte complexes (COCs) were vitrified either shortly after recovery (germinal vesicle stage, GV) or after maturation in vitro (IVM); cryoprotectant-treated and -untreated non-frozen oocytes served as controls....
McFarlane D, Sellon DC, Gaffney D, Hedgpeth V, Papich M, Gibbs S.To compare hematologic and serum biochemical variables and plasma ACTH concentration between healthy horses 5 to 12 years old and those more than 20 years old. Methods: 30 healthy horses 5 to 12 years old and 30 healthy horses more than 20 years old. Methods: Venous blood was collected from all horses, and CBC and serum biochemical analysis were performed for each horse. Plasma ACTH concentration was determined by radioimmunoassay. Student's paired t-test or the Mann-Whitney rank sum test was used to compare values between control and aged horse groups. Results: Compared with values for contro...
Todd FG, Stermitz FR, Schultheis P, Knight AP, Traub-Dargatz J.Horses in a few, localized northern Colorado pastures exhibited weight loss and colic. At post mortem, intestinal fibrosis and vascular sclerosis of the small intestine was identified. The pastures where the affected horses grazed were overrun by field bindweed (Convolvulus arvensis). Bindweed from the pasture was found to contain the tropane alkaloids tropine, pseudotropine, and tropinone and the pyrrolidine alkaloids cuscohygrine and hygrine. Laboratory mice readily ate C. arvensis and exhibited a variety of abnormal clinical signs depending on the amount eaten. Similar alkaloids have been f...
Lara F, Castro R, Thomson P.The gut microbiome is a compound for millions of microorganisms that coexist in an organized way and contribute to the fermentation of different types of indigestible fibers by the small intestine. Some techniques, such as the massive sequencing of the 16S ribosomal RNA gene, have made it possible to obtain information about the abundance and functionality of the microorganisms that compose the equine gut microbiome and the interaction with their environment. Recent studies have identified the change in the composition of the intestinal microbiome during and after a colic episode, although is ...
Flethøj M, Kanters JK, Haugaard MM, Pedersen PJ, Carstensen H, Balling JD, Olsen LH, Buhl R.OBJECTIVE To evaluate heart rate, heart rate variability, and arrhythmia frequency as well as changes in cardiac biomarker values and their association with heart rate in horses before and after an endurance ride. DESIGN Cross-sectional study. ANIMALS 28 Arabian horses competing in a 120- or 160-km endurance ride. PROCEDURES ECG recordings were obtained from each horse before (preride) and after (recovery) an endurance ride to evaluate changes in heart rate and the SD of normal R-R intervals (SDNN) during the initial 12 hours of recovery. Frequencies of supraventricular and ventricular prematu...
Cywinska A, Szarska E, Kowalska A, Ostaszewski P, Schollenberger A.Exercise-induced intravascular haemolysis and "sport anemia" are widely reported in human sports medicine. It has been recognized also in horses, however, the clinical importance and the onset of this condition seem different than in human. In this study we investigated the episodes of intravascular haemolysis, indicated by the increase in plasma haemoglobin and the decrease in serum haptoglobin levels, after routine training sessions in race horses. Heart rate and changes in haematological parameters confirmed, that the exertion was relatively high. Intravascular haemolysis did not appear in ...
Contalbrigo L, Borgi M, De Santis M, Collacchi B, Tuozzi A, Toson M, Redaelli V, Odore R, Vercelli C, Stefani A, Luzi F, Valle E, Cirulli F.Equine-assisted interventions (EAIs) are well-known complementary practices combining physical activity with emotional/cognitive stimulation. They are especially suited for children with autism spectrum disorders (ASD) who need a high degree of physical and psychological enrichment. Even though EAIs have become a common practice, stress responses in horses interacting with individuals that can manifest inappropriate behaviours, such as ASD children, have not been thoroughly investigated. Our multicentre study aimed to investigate behavioural and physiological indices of stress in horses involv...
Mohammadi-Sangcheshmeh A, Held E, Ghanem N, Rings F, Salilew-Wondim D, Tesfaye D, Sieme H, Schellander K, Hoelker M.Efficiencies for in vitro production of equine embryos are still low due to highly variable developmental competences of equine immature oocytes. In contrast to the equine, in vitro developmental competence of immature oocytes has been predicted successfully by the activity of glucose-6-phosphate dehydrogenase (G6PDH) indicated by brilliant cresyl blue (BCB) dye in a range of different species. Therefore, the aim of the present study was to test the association between G6PDH activity in equine oocytes with: (1) cumulus morphology and oocyte properties in terms of diameter and volume; (2) matur...
Irvine CH, Evans MJ.Total tyhroxine (TT4), free thyroxine (FT4), total triiodothyronine (TT3) and free triiodothyronine (FT3) concentrations in foal umbilical cord blood were respectively 14, 5 7 and 3 times the concentrations of these hormones in adult horse blood. The TT4 levels in foals declined rapidly to reach adult concentrations by Day 16 and FT4 levels declined steadily during the first 3 months of life. Foal TT3 levels rose during the first 10 hr after birth and thereafter declined, although they were still X2-5 higher than adult levels at 3 months of age. Levels of FT3 similarly increased after birth be...
Raeside JI.The role of steroids in human medicine is well recognized, but the major contributions made by the large domestic animals as a source of material in the discovery, isolation, and determination of the structure of the steroid hormones is less well appreciated. After a brief reminder of the early efforts to obtain a reliable source of steroids for clinical use, the narrative here is to outline one example where success was ultimately achieved for estrogen replacement therapy. Whereas knowledge of the high concentrations of estrogens in urine of pregnant women and mares dates from the late 1920s,...
Courouce-Malblanc A, Deniau V, Rossignol F, Corde R, Leleu C, Maillard K, Pitel PH, Pronost S, Fortier G.Dorsal displacement of the soft palate (DDSP) is one of the most common obstructive conditions of the upper respiratory tract in the racehorse. This condition has a complex aetiology which may be caused or exacerbated by pharyngeal inflammation. Additionally, lower respiratory airway diseases may be associated with DDSP thereby contributing to exercise intolerance in these horses. Objective: The aim of this study was to measure physiological variables during a standardised exercise test and to assess the prevalence and consequences of lower respiratory airway disease in horses with DDSP. Metho...
Morrell JM, Georgakas A, Lundeheim N, Nash D, Davies Morel MC, Johannisson A.Removing most of the seminal plasma (SP) from stallion semen has been shown to improve survival during cooled storage, yet adding small quantities of SP may improve pregnancy rates or cryosurvival. Furthermore, there is considerable controversy about whether the stallion's own SP or heterologous SP produces the best effect, possibly because of the variation between stallions in SP proteins or because some homologous SP remained in the sperm preparation. The SP is removed completely from stallion spermatozoa prepared by colloid centrifugation. Thus, the aim of the present study was (1) to inves...
Alterisio A, Baragli P, Aria M, D'Aniello B, Scandurra A.In order to explore the decision-making processes of horses, we designed an impossible task paradigm aimed at causing an expectancy violation in horses. Our goals were to verify whether this paradigm is effective in horses by analyzing their motivation in trying to solve the task and the mode of the potential helping request in such a context. In the first experiment, 30 horses were subjected to three consecutive conditions: no food condition where two persons were positioned at either side of a table in front of the stall, solvable condition when a researcher placed a reachable reward on the ...
Ohmura H, Hiraga A, Aida H, Kuwahara M, Tsubone H.To determine the effects of initial handling and training on autonomic nervous functions in young Thoroughbreds. Methods: 63 healthy Thoroughbreds. Methods: All horses were trained to be handled and initially ridden in September of the yearling year and then trained until the following April by conventional training regimens. To obtain the heart rate (HR), electrocardiograms were recorded in the stable before initial handling and training and following 7 months of training; variations in HR were then evaluated from the power spectrum in terms of the low frequency (LF; 0.01 to 0.07 Hz) power an...
Hewetson M, Sykes BW, Hallowell GD, Tulamo RM.Equine gastric ulcer syndrome (EGUS) is common in adult horses, particularly those involved in performance disciplines. Currently, detection of EGUS by gastroscopy is the only reliable ante mortem method for definitive diagnosis; however it is unsuitable as a screening test because it is expensive, time consuming, and is not readily available to most veterinarians. Sucrose permeability testing represents a simple, economical alternative to gastroscopy for screening purposes, and the feasibility of this approach in the horse has been previously reported. The aim of this study was to determine t...
Lacombe VA, Hinchcliff KW, Kohn CW, Devor ST, Taylor LE.To determine effects of feeding diets with various soluble-carbohydrate (CHO) content on rates of muscle glycogen synthesis after exercise in horses. Methods: 7 fit horses. Methods: In a 3-way crossover study, horses received each of 3 isocaloric diets (a high soluble CHO [HC] diet, a low soluble CHO [LC] diet, or a mixed soluble CHO [MC] diet). For each diet, horses were subjected to glycogen-depleting exercise, followed by feeding of the HC, LC, or MC diet at 8-hour intervals for 72 hours. Results: Feeding the HC diet resulted in a significantly higher glycemic response for 72 hours and sign...
van Eps AW, Pollitt CC.The hypometabolic and vasoconstrictive effects of cryotherapy could prevent the development of laminitis. Objective: To use distal limb cryotherapy to prevent laminitis induced by alimentary carbohydrate overload. Methods: Laminitis was induced in 6 Standardbred horses that had one front limb continuously cooled in an ice/water mixture. Lameness evaluation, blinded lamellar histological grading and analysis for lamellar matrix metalloproteinase-2 (MMP-2) mRNA expression were used to evaluate the severity of laminitis. Results: Cryotherapy was well tolerated and effective in cooling the feet. I...
Meschan EM, Peham C, Schobesberger H, Licka TF.As there is no statistical evidence that saddle fit influences the load exerted on a horse's back, this study was performed to assess the hypothesis that the width of the tree significantly alters the pressure distribution on the back beneath the saddle. Nineteen sound horses were ridden at walk and trot on a treadmill with three saddles differing only in tree width. Kinetic data were recorded by a sensor mat. A minimum of 14 motion cycles were used in each trial. The saddles were classified into four groups depending on fit. For each horse, the saddle with the lowest overall force (LOF) was d...
Paul LJ, Ericsson AC, Andrews FM, Keowen ML, Morales Yniguez F, Garza F, Banse HE.The role of the gastric microbiome in development or persistence of equine glandular gastric disease (EGGD) remains to be investigated. Objective: The objective was to characterize the glandular mucosal and gastric fluid microbiomes of horses with and without EGGD. It was hypothesized that differences in the mucosal microbiome are associated with EGGD. Methods: Twenty-four horses were enrolled. Methods: Gastroscopy was performed and EGGD scores recorded (score 0, n = 6; score 1, n = 8; score ≥2, n = 10). Gastric fluid and pinch biopsies of healthy glandular mucosa and EGGD lesions were...
Prince A, Geor R, Harris P, Hoekstra K, Gardner S, Hudson C, Pagan J.In order to compare the metabolic responses to exercise in 2 similarly managed breeds of horses, 5 Arabian (AR) and 5 Thoroughbred (TB) horses, fed an identical diet with a similar diet and exercise training programme for the 2 preceding months, undertook 3 treadmill (3 degree incline) trials with a minimum of 7 days between tests: 1) an incremental test (MAX) for determination of aerobic capacity, V(LA4) and lactate threshold (LT; the percentage of VO2max when plasma lactate = 4 mmol/l); 2) a single high-speed exercise test (SPR) at 115% VO2max for estimation of maximal accumulated oxygen def...
Barussi FC, Bastos FZ, Leite LM, Fragoso FY, Senegaglia AC, Brofman PR, Nishiyama A, Pimpão CT, Michelotto PV.This research evaluated the effects of bone marrow-derived mononuclear cells (BMMCs) on the inflammatory process in the equine recurrent airway obstruction (RAO). Eight horses in RAO clinical score were divided into cell therapy group (Gcel) treated with a single intratracheal dose of BMMCs, and dexamethasone group (Gdex) treated with 21days of oral dexamethasone. The horses were clinically revaluated on days 7 and 21, together with cytological evaluation of the BALF, and detection of inflammatory markers (interleukins [IL]-10, -4, and -17, and interferon γ and α). There were decreases in re...
Rivero JL.The main goal of any conditioning programme in athletic horses is to improve performance by inducing physiological changes within the animal's body. Equine skeletal muscles have a considerable potential to adapt during training and these adaptations have important physiological implications that influence stamina, strength and speed. Although there is an extensive specialized literature in this regard, scientific based muscle conditioning methods have not been introduced sufficiently in the equine sport practice. After a brief synopsis of both equine muscle exercise physiology and muscular ada...
van Eps AW, Orsini JA.Digital hypothermia may be effective for laminitis prophylaxis and therapy, but the efficacy of cooling methods used in clinical practice requires evaluation. Objective: To use hoof wall surface temperature (HWST) to compare several cooling methods used in clinical practice. Methods: Experimental crossover design with a minimum washout period of 72 h. Methods: Seven cooling methods (commercially available ice packs, wraps and boots) and one prototypical dry-sleeve device were applied to a single forelimb in 4 horses for 8 h, during which HWST of the cooled forelimb and the uncooled (contro...
Squires EL, Keith SL, Graham JK.Although use of cryopreserved stallion spermatozoa is currently accepted by many breed registries, utilization of this technique remains limited due to poor fertility for some stallions. One reason for these results is osmotic stress that spermatozoa experiences when the cryoprotectant (glycerol) is added to the cells prior to freezing and removal from the cells after thawing. In an effort to minimize osmotic damage, alternative cryoprotectants, having lower molecular weights and greater membrane permeability than glycerol, were evaluated to determine their effectiveness for cryopreserving sta...
