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.
Kelley D, LeBlanc MM, Warren LK, Mortensen CJ.Supplementation with L-arginine can increase uterine arterial blood flow and vascular perfusion of the preovulatory follicle in mares. Increased vascular perfusion of the preovulatory follicle has been correlated with successful pregnancy in mares. The objective of this study was to determine if supplemental L-arginine would increase ovarian arterial blood flow, vascular perfusion of the preovulatory follicle, and embryo recovery rates in mares. Mares were blocked by age and breed and assigned at random within block to L-arginine supplementation or control groups. Mares were fed L-arginine beg...
Clayton HM, Nauwelaerts S.In a standing horse the centre of pressure (COP), measured as the resultant vertical ground reaction force (GRF) of all supporting limbs, is adjusted in response to visual, vestibular and proprioceptive information. Stabilographic analysis measures balance by tracking COP movements in the horizontal plane. Loss of visual input affects stability of balance in people and has clinical implications in that instability inherent in some neurological diseases increases with the eyes closed. The objectives of this study were to evaluate the visual contribution to postural stability in horses. The hypo...
Bromfield EG, Aitken RJ, Gibb Z, Lambourne SR, Nixon B.While IVF has been widely successful in many domesticated species, the development of a robust IVF system for the horse remains an elusive and highly valued goal. A major impediment to the development of equine IVF is the fact that optimised conditions for the capacitation of equine spermatozoa are yet to be developed. Conversely, it is known that stallion spermatozoa are particularly susceptible to damage arising as a consequence of capacitation-like changes induced prematurely in response to semen handling and transport conditions. To address these limitations, this study sought to develop a...
Carvalho AM, Yamada AL, Golim MA, Álvarez LE, Hussni CA, Alves AL.Mesenchymal stem cells (MSCs) have been used to treat equine tendonitis with promising results; however, little is known about the potential migration of these cells. Objective: To assess the possible migration of MSCs from an implantation site in the superficial digital flexor tendon (SDFT) to a lesion in the SDFT of the contralateral limb. Methods: In vivo experimental study. Methods: Adipose-derived MSCs were isolated from 4 healthy horses. Lesions were induced in the SDFTs of both forelimbs, followed by intralesional implantation of autologous adipose-derived MSCs labelled with nanocrystal...
Hendrickson SL.Life at high altitude results in physiological and metabolic challenges that put strong evolutionary pressure on performance due to oxidative stress, UV radiation and other factors dependent on the natural history of the species. To look for genes involved in altitude adaptation in a large herbivore, this study explored genome differentiation between a feral population of Andean horses introduced by the Spanish in the 1500s to the high Andes and their Iberian breed relatives. Results: Using allelic genetic models and Fst analyses of ~50 K single nucleotide polymorphisms (SNPs) across the horse...
Silva ES, Frade SC, Ignácio FS, Pantoja JC, Puoli Filho JN, Meira C.The present study evaluated the effect of altrenogest treatment during 70 or 120 days of gestation on pregnancy maintenance in non-cyclic recipient mares and correlated the hormonal interruption findings with number, supplementary corpora lutea (SCL) formation period, and plasma progesterone (P4). Twenty five mares were used as recipients during anestrus, transitional or ovulatory phase and were assigned into groups according to altrenogest treatment period (70ALT, 120ALT or Control groups) or reproductive status at beginning of treatment (Anestrus, Transition or Cyclic/Control groups). Mares ...
De-Simone SG, Napoleão-Pêgo P, Teixeira-Pinto LA, Melgarejo AR, Aguiar AS, Provance DW.The presence of whole horse IgG in therapeutic snake antivenom preparations of high purity is a contamination that can cause IgE-mediated allergic reactions in patients. In this study, the immunodominant IgE and IgG-binding epitopes in horse heavy chain IgG3 were mapped using arrays of overlapping peptides synthesized directly onto activated cellulose membranes. Pooled human sera from patients with and without horse antivenom allergies were used to probe the membrane. We have demonstrated that, for both cases, individuals produce antibodies to epitopes of sequential amino acids of horse heavy ...
Zebisch A, May A, Reese S, Gehlen H.Different head-neck positions (HNPs) are used in equestrian sports and are regarded as desirable for training and competition by riders, judges and trainers. Even though some studies have been indicative of hyperflexion having negative effects on horses, this unnatural position is frequently used. In the present study, the influence of different HNPs on physical and psychological stress parameters in the ridden horse was investigated. Heart rate (HR), heart rate variability (HRV) and blood cortisol levels were measured in 18 horses. Low frequency (LF) and high frequency (HF) are power componen...
Zebisch A, May A, Reese S, Gehlen H.Hyperflexion, that is the strong deflection of the horse's head, poll and neck, is a prevalent training technique in equitation. Hyperflexion has come under criticism in recent years for being suspected of affecting the horses' well-being contrary to animal welfare. The goal of the present study is a comparison between the impacts of different poll-neck positions on findings in the upper respiratory tract of ridden horses. For this purpose, video recordings of the larynges of 14 horses were taken using an overground endoscope. The videos were recorded at rest and during three different riding ...
Monk CS, Hart KA, Berghaus RD, Norton NA, Moore PA, Myrna KE.To determine whether cortisol is present in equine tears at rest and during simulated stress and compare tear cortisol to serum free and total cortisol. Methods: Fourteen healthy adult horses were included. Paired tear total cortisol and serum total and free cortisol concentrations were measured with ELISA, chemiluminescent immunoassay, and ultrafiltration methodology, respectively, in 10 horses at rest once daily for five consecutive days. In an additional four horses, paired tear and serum samples were collected for cortisol measurement before and after adrenocorticotropic hormone (ACTH) sti...
Gil L, Galindo-Cardiel I, Malo C, González N, Alvarez C.Cholesterol and Equex-STM are frequently added to different commercial and experimental extenders improving postthawing sperm quality. Doses of 125-150 mM of cholesterol from pig liver and 0.5-0.7% of Equex-STM were evaluated in a standard eggyolk extender (Martin et al., 1979). Six ejaculates per stallion from six pure Spanish stallions (6-8 years old) were collected in Martin's extender (B) and different mixtures of 125 mM-0.5% (I), 125 mM-0.7% (II), 150 mM-0.5% (III), and 150 mM-0.7% (IV) were added to original Martin's extender. Samples were frozen in 0.5 mL straws (100 × 10(6...
Hopster K, Ohnesorge B, von Borstel M, Rohn K, Kästner S.In most ocular procedures, a central position of the eye is necessary. This can be achieved using a deep plane of anaesthesia, locoregional blocks or with neuromuscular blocking agents. The aim of this study was to evaluate the influence of atracurium on cardiovascular parameters, and on recovery quality and duration in horses. Methods: Thirty-four warmblood horses undergoing in total 50 vitrectomies were divided into two groups. Premedication, induction and maintenance were identical in all patients. After 20 minutes, horses of group A received atracurium (0.1 mg/kg) while in the control grou...
Al-Jaru A, Goodwin W, Skidmore J, Khazanehdari K.Advances in molecular cytogenetics have provided the opportunity to study events during prophase I of meiosis. Immunofluorescent localization of different meiotic protein components were used to characterize the early stages of the first meiotic division in horse spermatocytes. The frequency and distribution of recombination events during prophase I were investigated using the mutL homolog 1 (MLH1) protein that is known to be associated with these events. The frequency and distribution of MLH1 foci were investigated in pachytene nuclei of 6 fertile stallions, and the average relative synaptone...
Rumpler MJ, Colahan P, Sams RA.The disposition of plasma glycopyrrolate (GLY) is characterized by a three-compartment pharmacokinetic model after a 1-mg bolus intravenous dose to Standardbred horses. The median (range) plasma clearance (Clp), volume of distribution of the central compartment (V1 ), volume of distribution at steady-state (Vss), and area under the plasma concentration-time curve (AUC0-inf ) were 16.7 (13.6-21.7) mL/min/kg, 0.167 (0.103-0.215) L/kg, 3.69 (0.640-38.73) L/kg, and 2.58 (2.28-2.88) ng*h/mL, respectively. Renal clearance of GLY was characterized by a median (range) of 2.65 (1.92-3.59) mL/min/k...
Bazzano M, Giannetto C, Fazio F, Marafioti S, Giudice E, Piccione G.Hemostasis is a physiological process that prevents excessive blood loss and represents a protective mechanism at the time of delivery. Peripartum hemorrhage is a recurring hazardous condition to mare's health; therefore, we aimed to study mares' hemostatic profile to investigate whether physiological adjustments occur during late pregnancy and early postpartum. Fifteen pregnant mares have been monitored from the 34th week of pregnancy until the third week after foaling. Fifteen nonpregnant mares were used as control group. Jugular blood samples were analyzed for platelet count (Plt), prothrom...
Richards SL, Cawley AT, Raftery MJ.Dermorphin, a hepta-peptide with potent analgesic properties, is classified as a doping agent in equine racing. Since its discovery, a number of biologically active structural analogs have been synthesized and made commercially available so there is a need for reliable methods of detection. Results: A sensitive detection method was developed for dermorphin and six analogs in equine urine. Peptide enrichment was achieved using weak cation exchange with subsequent separation and detection by nano-UHPLC-MS/MS. Method validation parameters included: specificity, linearity (5-10000 pg/ml), recovery...
Dyson S.Nuclear scintigraphic examination of equine athletes has a potentially important role in the diagnosis of lameness or poor performance, but increased radiopharmaceutical uptake (IRU) is not necessarily synonymous with pain causing lameness. Nuclear scintigraphy is highly sensitive to changes in bone turnover that may be induced by loading and knowledge of normal patterns of RU is crucial for accurate diagnosis. Blood pool images can be useful for identification of some soft tissue injuries, although acute bone injuries may also have intense IRU in blood pool images. Some muscle injuries may be...
Jülke H, Veit C, Ribitsch I, Brehm W, Ludewig E, Delling U.The purpose of this study was to evaluate the use of three different superparamagnetic iron oxide (SPIO) particles for labeling of ovine and equine bone marrow (BM)-derived multipotent stromal cells (MSCs) in vitro. MSCs were obtained from five adult sheep and horses, respectively. After three passages (p3), cells were labeled with either 1) Molday ION Rhodamine B, 2) Endorem, 3) Resovist, or 4) remained unlabeled as control. Labeling efficiency, marker retention, and long-term detectability in MRI until p7 were evaluated. Further, proliferation capacity and trilineage differentiation as indic...
Thorson JF, Allen CC, Amstalden M, Williams GL.The continuous, subcutaneous infusion of native GnRH into seasonally anovulatory mares stimulates the synthesis and secretion of LH without pituitary refractoriness, offering opportunities to markedly accelerate the timing of ovulation within the operational breeding season. Herein, we tested the hypothesis that ovarian cycles induced in winter anovulatory mares using continuous administration of native GnRH for 28 days, beginning in either early February or early March (North America) would not revert to an anovulatory state after treatment withdrawal. Anovulatory mares received sham pumps (c...
Thorson JF, Prezotto LD, Cardoso RC, Allen CC, Alves BR, Amstalden M, Williams GL.Onset of the winter anovulatory period in mares is associated with a marked diminution in adenohypophyseal synthesis and release of LH. Native GnRH, unlike its synthetic agonists, stimulates the synthesis and secretion of LH in mares without pituitary refractoriness. Herein we tested the hypotheses that (1) the average Julian day of pregnancy can be accelerated by up to 2 months in winter anovulatory mares treated continuously with native GnRH beginning on February 1 and (2) mares will sustain luteal function and pregnancy after treatment withdrawal. Forty-two winter anovulatory mares were str...
Baghi HB, Laval K, Favoreel H, Nauwynck HJ.The nasal mucosa surface is continuously confronted with a broad variety of environmental antigens, ranging from harmless agents to potentially harmful pathogens. This area is under rigorous control of professional antigen presenting cells (APCs), such as dendritic cells (DCs) and macrophages. Mucosal APCs play a crucial role in inducing primary immune responses and the establishment of an immunological memory. In the present study, a detailed characterization of CD172a(+) cells, containing the APCs residing in the equine nasal mucosa was performed for the first time. CD172a(+) cells were isol...
François I, Lalèyê FX, Micat M, Benredouane K, Portier K.Some controversy exists over whether or not horses' recovery and cardiopulmonary function are affected by suspension in slings. Objective: To measure arterial oxygen tension and pulmonary ventilation in anaesthetised horses placed in a standing position in an Anderson Sling (AS) after a period of right lateral recumbency (RLR). Methods: Randomised crossover experimental study. Methods: Six Standardbred horses were anaesthetised twice. Catheters were inserted into the right jugular vein and the left carotid artery. After premedication with romifidine, anaesthesia was induced with diazepam and k...
Shoemaker L, Clauset A.Horses (family Equidae) are a classic example of adaptive radiation, exhibiting a nearly 60-fold increase in maximum body mass and a peak taxonomic diversity of nearly 100 species across four continents. Such patterns are commonly attributed to niche competition, in which increased taxonomic diversity drives increased size disparity. However, neutral processes, such as macroevolutionary 'diffusion', can produce similar increases in disparity without increased diversity. Using a comprehensive database of Equidae species size estimates and a common mathematical framework, we measure the contribu...
Ambrisko TD, Lammer V, Schramel JP, Moens YP.A spirometry device equipped with mainstream CO2 flow sensor is not available for large animal anaesthesia. Objective: To measure the resistance of a new large animal spirometry device and assess its agreement with reference methods for volume measurements. Methods: In vitro experiment and crossover study using anaesthetised horses. Methods: A flow partitioning device (FPD) equipped with 4 human CO2 flow sensors was tested. Pressure differences were measured across the whole FPD and across each sensor separately using air flows (range: 90-720 l/min). One sensor was connected to a spirometry ...
Péron F, Ward R, Burman O.Knowledge about social recognition and memory in animals can help us to determine appropriate management and husbandry techniques. In this study, we used a habituation-discrimination procedure to investigate the ability of horses (Equus caballus) to distinguish between the body odour samples of unfamiliar conspecifics. To pick up body odour, we rubbed material on the coat of horses and presented these unknown body odours to 16 different conspecifics of the same sex and similar age. The test consisted of two successive two-min presentations of a sample from one individual (e.g. individual 'A') ...
Cozzi B, Povinelli M, Ballarin C, Granato A.The horse is a common domestic animal whose anatomy has been studied since the XVI century. However, a modern neuroanatomy of this species does not exist and most of the data utilized in textbooks and reviews derive from single specimens or relatively old literature. Here, we report information on the brain of Equus caballus obtained by sampling 131 horses, including brain weight (as a whole and subdivided into its constituents), encephalization quotient (EQ), and cerebellar quotient (CQ), and comparisons with what is known about other relevant species. The mean weight of the fresh brains in o...
Reyes AM, Jahr H, van Schie HT, Weinans H, Zadpoor AA.The elastic strain limit (ESL) of tendons is the point where maximum elastic modulus is reached, after which micro-damage starts. Study of damage progression in tendons under repetitive (fatigue) loading requires a priori knowledge about ESL. In this study, we propose three different approaches for predicting ESL. First, one single value is assumed to represent the ESL of all tendon specimens. Second, different extrapolation curves are used for extrapolating the initial part of the stress-strain curve. Third, a method based on comparing the shape of the initial part of the stress-strain curve ...
Gilmour MA, Clarke CR, Macallister CG, Dedeo JM, Caudell DL, Morton RJ, Pugh M.To investigate intraocular penetration of orally administered doxycycline in the normal equine eye and to compare intraocular and serum doxycycline concentrations. Procedures Six mares were administered doxycycline at 10 mg/kg every 12 h by nasogastric tube for 5 days. Blood, aqueous, and vitreous samples were collected on days 1 and 5. All samples were assayed for doxycycline concentrations. Aqueous and vitreous samples were also assayed for protein quantitation. Results: Doxycycline was rapidly absorbed after the first dose (T(max) value of 1.42 +/- 1.28 h); and elimination of doxycycline oc...
Klein C, Troedsson M.During the second and third week of pregnancy, the equine conceptus is covered by an acellular glycoprotein capsule. This capsule contains glycoproteins resembling those of the mucin family with sialic acid making up a high proportion of the carbohydrate. Coinciding with conceptus fixation, a marked decline in sialic acid content of the capsule occurs, which has been proposed to contribute to cessation of conceptus mobility. Herein, we describe the expression of neuraminidase 2 (NEU2) by pre-implantation stages of equine conceptus development. NEU2 transcript abundance was examined in conceptu...
Yamano S, Kawai M, Minami Y, Hiraga A, Miyata H.We evaluated differences in muscle fiber recruitment patterns between continuous and interval training to develop an optimal training program for Thoroughbred horses. Five well trained female thoroughbred horses (3-4 years old) were used. The horses performed two different exercises on a 10% inclined treadmill: 90%VO2 max for 4 min (continuous) and 90% VO2 max for 2 min × 2 times with 10-min interval (interval). Muscle samples were obtained from the middle gluteal muscle before and immediately after the exercises. Four muscle fiber types (type I, IIA, IIA/X, and IIX) were immunohistochemicall...
Yamano S, Eto D, Kasashima Y, Hiraga A, Sugiura T, Miyata H.To determine the growth-related changes in metabolic and anatomic properties in equine muscle fiber type, including hybrid fibers identified with immunohistochemical analysis. Methods: 24 2-, 6-, 12-, and 24-month-old female Thoroughbreds. Methods: Samples were obtained from the gluteus medius muscle of all horses. Expression of myosin heavy chain (MHC) isoforms MHC-I, -IIa, -IIb, and -IIx in each muscle fiber was detected by use of 4 primary monoclonal antibodies: BA-D5, SC-71, BF-F3, and BF-35, respectively. Five muscle fiber types (types I, I/IIA, IIA, IIA/IIX, and IIX) were immunohistochem...
Latham CM, Fenger CK, White SH.Responses of equine skeletal muscle characteristics to growth and training have been shown to differ between breeds. These differential responses may arise in part because muscle fiber type and mitochondrial density differ between breeds, even in untrained racing-bred horses. However, it is not known when these breed-specific differences manifest. To test the hypothesis that weanling Standardbreds (SB) and Thoroughbreds (TB) would have higher mitochondrial measures than Quarter Horses (QH), gluteus medius samples were collected from SB (mean ± SD; 6.2 ± 1.0 mo; n = 10), TB (6.1 ± 0.5 mo; n ...
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...
Ryan JM, Cobb MA, Hermanson JW.Based on histochemical and immunohistochemical evidence, horse elbow extensor muscles are composed of two morphologically distinct muscle groups. The long and lateral heads of the triceps brachii are large, predominantly type II (presumed fast) muscles. The long and lateral heads of the triceps together account for 96% of the weight of the elbow extensors (long head of triceps is 81%). The long and lateral heads contain three histochemical fiber types: types I, IIa and IIb. Type I muscle fibers account for approximately 18 and 27% of the fibers in the long and lateral heads of the triceps, res...
Fontaine GL, Belknap JK, Allen D, Moore JN, Kroll DL.To study expression of interleukin-1beta (IL-1beta) in the digital laminae of horses in the prodromal stage of experimentally induced laminitis. Methods: 8 healthy adult horses with no signs of laminitis. Methods: Black walnut extract was administered via nasogastric tube to 4 horses, and water was administered to the remaining 4 (controls). Complete blood counts and physical examinations were performed every 30 minutes after administration of black walnut extract or water. General anesthesia was induced when total WBC count decreased by 30% in horses given the black walnut extract and 3 hours...
Wolf CA, Maslchitzky E, Gregory RM, Jobim MI, Mattos RC.The objective was to determine the effects of corticotherapy, in the presence and absence of uterine inflammation, on proteomics of endometrial fluid from mares susceptible to endometritis. In 11 mares, estrus was induced seven times with 5 mg PGF(2α) given at 14-day intervals. The first estrus was a control (no treatment). During the third estrus, mares received glucocorticoid (GC) treatment (20 mg isoflupredone acetate) every 12 h, for three consecutive days. The fifth estrus was the Infected treatment (intrauterine infusion of 1 × 10(9) colony-forming unit/mL Streptococcus equi subspecies...
Cuervo-Arango J, Clark A.The mare is a seasonally polyestrus breeder. In early spring, the mare enters a "transition period" between the anovulatory season and the first ovulation of the year. This period is characterized by irregular estrus cycles and high incidence of regressing dominant follicles. There is a belief that pregnancy rates resulting from the first ovulation of the season is lower than in subsequent ovulations, however this has never been studied critically. Progestagens are often used as an aid to manage the transition period. The objective of this study was to compare pregnancy rates of mares from the...
Manohar M, Goetz TE.The present study was carried out to examine the effects of nitric oxide synthase inhibition with Nomega-nitro-L-arginine methyl ester (L-NAME) on the right atrial as well as on the pulmonary arterial, capillary, and venous blood pressures of horses during rest and exercise performed at maximal heart rate (HRmax). Experiments were carried out on seven healthy, sound, exercise-trained Thoroughbred horses. Using catheter-tip manometers, with signals referenced at the point of the shoulder, we determined phasic and mean right atrial and pulmonary vascular pressures in two sets of experiments [con...
Maurício LS, Leme DP, Hötzel MJ.Stabled horses often experience negative emotions due to the inappropriate living conditions imposed by humans. However, identifying what emotions horses experience and what can trigger positive and negative emotions in stabled horses can be challenging. In this article we present a brief history of the study of emotions and models that explain emotions from a scientific point of view and the physiological bases and functions of emotions. We then review and discuss physiological and behavioral indicators and cognitive bias tests developed to assess emotions in horses. Hormone concentrations, b...
Canesin HS, Brom-de-Luna JG, Choi YH, Pereira AM, Macedo GG, Hinrichs K.Previous studies have found low rates of blastocyst development (0-11%) after vitrification of germinal vesicle (GV)-stage equine oocytes. In this study, we systematically evaluated a short (non-equilibrating) system for GV-stage oocyte vitrification. In Exp. 1, we assessed oocyte volume in cumulus-oocyte complexes (COCs) exposed to components of a short protocol, using 2% each of ethylene glycol and propylene glycol in the first solution (VS1); 17.5% of each plus 0.3 M trehalose in the second solution (VS2); and fetal bovine serum as the base medium. Based on the time to oocyte minimum volu...
Mitchell SR, Kempson SA, Dixon PM.The structure of peripheral cementum of mandibular and maxillary cheek teeth was studied by gross observation, light microscopy, and scanning and transmission electron microscopy. Teeth from four horses aged 4, 8, 17, and 30-years-old were examined. The cementum of the occlusal surface was thicker on the buccal aspect when compared with the lingual aspect of mandibular teeth. The cementum of the occlusal surface was thicker on the palatal aspect when compared with the buccal aspect of maxillary teeth. There was no peripheral cementum on the interdental aspects of either mandibular or maxillary...
Bolfă PF, Leroux C, Pintea A, Andrei S, Cătoi C, Taulescu M, Tăbăran F, Spînu M.This study assesses the impact of equine infectious anaemia virus (EIAV) infection on the oxidant/antioxidant equilibrium of horses. Blood samples from 96 Romanian horses aged 1-25 years, were divided into different groups according to their EIAV-infection status, age, and time post-seroconversion. The effect of infection on oxidative stress was estimated by measuring enzymatic antioxidants (superoxide dismutase [SOD], glutathione peroxidase [GPx] and catalase), non-enzymatic antioxidants (uric acid and carotenoids), and lipid peroxidation (malondialdehyde [MDA]). Infection modified the oxidan...
DNA repairNovember 12, 2020
Volume 97 103022 doi: 10.1016/j.dnarep.2020.103022
Chen L, Bellone RR, Wang Y, Singer-Berk M, Sugasawa K, Ford JM, Artandi SE.Squamous cell carcinoma (SCC) occurs frequently in the human Xeroderma Pigmentosum (XP) syndrome and is characterized by deficient UV-damage repair. SCC is the most common equine ocular cancer and the only associated genetic risk factor is a UV-damage repair protein. Specifically, a missense mutation in horse DDB2 (T338M) was strongly associated with both limbal SCC and third eyelid SCC in three breeds of horses (Halflinger, Belgian, and Rocky Mountain Horses) and was hypothesized to impair binding to UV-damaged DNA. Here, we investigate DDB2-T338M mutant's capacity to recognize UV lesions in ...
Caillaud M, Gérard N.We analysed the effect of interleukin-1 on oocyte maturation and on steroid and prostaglandin production by equine granulosa and cumulus cells. In Experiment 1, interleukin-1beta (IL-1beta) was injected into the growing dominant follicle, which was punctured 38 h later. Follicular fluid was assayed for steroids and prostaglandin-F2alpha (PGF2alpha). Granulosa cells were analysed for 3beta-hydroxysteroid dehydrogenase (3beta-HSD), progesterone receptor (PR), cyclooxygenase 1 and 2 (Cox 1 and Cox 2) and steroidogenic acute regulatory protein (StAR) mRNAs. In Experiment 2, cumulus-oocyte complexe...
Acosta JAD, Elghandour MMMY, Mariezcurrena-Berasain MD, Adegbeye MJ, Fajemisin AN, Pliego AB, Salem AZM.This study aimed to evaluate the dietary administration of the Caesalpinia coriaria (CC) extract for 30 days on in vitro fecal greenhouse gases production. Fecal samples, as inoculums, were collected from horses given daily 0- (Fecal 0), 60- (Fecal 60) and 120- (Fecal 60) mL CC aqueous extract per animal. The extract dose was mixed with the morning feeding diet at 6:00 h for each horse. During incubation, 0-, 0.6-, 1.2- and 1.8-mL CC extracts were added to the basal diet which was fed to horses (as subtract) and evaluated with each fecal type. Feces from the horses given no CC extract produc...
Suganuma K, Yamasaki S, Molefe NI, Musinguzi PS, Davaasuren B, Mossaad E, Narantsatsral S, Battur B, Battsetseg B, Inoue N.Dourine is caused by Trypanosoma equiperdum via coitus with an infected horse. Although dourine is distributed in Equidae worldwide and is listed as an internationally important animal disease by the World Organization for Animal Health (OIE), no effective treatment strategies have been established. In addition, there are no reports on drug discovery, because no drug screening system exists for this parasite. A new T. equiperdum strain was recently isolated from the genital organ of a stallion that showed typical symptoms of dourine. In the present study, we adapted T. equiperdum IVM-t1 from...
Jouglin M, Robert C, Valette JP, Gavard F, Quintin-Colonna F, Denoix JM.Early detection of osteoarthritis in horses represents a challenge for equine practitioners. Several biological markers have been implicated in the pathological processes involved in articular cartilage destruction. To further document cartilage matrix proteases production, synovial fluid was collected from 14 horses (90 joints) before they were subjected to euthanasia. Growth macroscopic examination of the joints gave information on cartilage alterations. Samples were analyzed for matrix metalloproteinase (MMPs) activities by gelatin zymography and tumor necrosis factor alpha (TNF-alpha) cyto...
Sinclair SE, McKinney S, Glenny RW, Bernard SL, Hlastala MP.We determined the changes in fractal dimensions and spatial correlations of regional pulmonary blood flow with increasing exercise in race horses (n = 4) by using 15-microm fluorescent microspheres. Fluorescence was measured to quantitate regional blood to 1.3-cm(3) samples (n = 1,621-2,503). Perfusion distributions were characterized with fractal dimensions (a measure of spatial variability) and spatial correlations. On average, the fractal dimension decreased with exercise (trot 1.216 to gallop 1.173; P < 0. 05) despite a variable fractal dimension at rest. Spatial correlation of flow to ...
Boyard-Kieken F, Dervilly-Pinel G, Garcia P, Paris AC, Popot MA, le Bizec B, Bonnaire Y.Growth hormone (GH) is a polypeptide suspected of being used in horse racing to speed up physical performances. Despite scientific advances in the recent years, the control of its administration remains difficult. In order to improve it, a metabolomics study through LC-high resolution mass spectrometry measurements was recently initiated to assess the metabolic perturbations caused by recombinant equine growth hormone administration. Few tens of ions not identified structurally were highlighted as compounds responsible for the modification of metabolic profiling observed in treated animals. Th...
Verheyen KL, Price JS, Wood JL.This study aimed to determine the effects of exercise on racecourse performance in horses racing on the flat. Daily exercise and race records were obtained over a 2-year period for a cohort of racehorses in training for which injury data were also available. Multivariable regression techniques were used to investigate associations between canter, training gallop and race distances accumulated in the 30 days prior to each race and the odds of winning the race, earning prize money and the amount of prize money won. Higher cumulative high-speed (gallop+race) distances were associated with increas...
Dahlgren LA, Mohammed HO, Nixon AJ.he treatment of overuse tendon injuries with exogenous growth factors such as insulin-like growth factor-I (IGF-I) may facilitate an improved return to sustained athletic function. The biological effects of IGF-I are exerted under the control of a complex of IGF receptors, binding proteins, and proteases. This IGF system includes a family of six structurally related high-affinity IGF binding proteins (IGFBPs) that protect IGF-I from local proteases and restrict access of IGF-I to its receptor. This study describes the expression of the IGFBPs in flexor tendon after acute injury and during heal...
Larenza MP, Landoni MF, Levionnois OL, Knobloch M, Kronen PW, Theurillat R, Schatzmann U, Thormann W.The arterial pharmacokinetics of ketamine and norketamine enantiomers after racemic ketamine or S-ketamine i.v. administration were evaluated in seven gelding ponies in a crossover study (2-month interval). Methods: Anaesthesia was induced with isoflurane in oxygen via a face-mask and then maintained at each pony's individual MAC. Racemic ketamine (2.2 mg kg(-1)) or S-ketamine (1.1 mg kg(-1)) was injected in the right jugular vein. Blood samples were collected from the right carotid artery before and at 1, 2, 4, 8, 16, 32, 64, and 128 min after ketamine administration. Ketamine and norketamine...
Trilk JL, Lindner AJ, Greene HM, Alberghina D, Wickler SJ.Blood lactate measurements are used widely in horses to assess athletic performance, but there are few published data on using lactate as a guide for endurance improvement. The velocity at which blood lactate concentration ([LA]) of 4 mmol/l is reached (v4) is widely used to determine fitness. In an earlier study of v4, exercise at low intensities for longer duration was more effective at improving endurance than shorter, higher intensities. However, the prescription was unchanged during the study (6 weeks). We hypothesised that, to produce greater improvement in v4 in the same time frame, it ...
Hendrickson EH, Malone ED, Sage AM.Six healthy horses were examined by using transabdominal ultrasonography, as described (1-3), to evaluate activity and size of the large colon and cecum at various locations. Using size and number of sacculations, activity patterns and contractile frequency; significant differences that would allow ultrasonographic identification of dorsal versus ventral colons, if they were displaced, were not found. The cecum had significantly greater activity than the colon, and a trend was seen towards smaller sacculations in the cecum than in the large colon. Six chevaux en santé ont été examinés par...
Albera R, Dagna F, Lacilla M, Canale A.Many different grafting materials have been proposed in myringoplasty. The aim of this study was to evaluate the results obtained in transmeatal underlay myringoplasty using bovine and equine pericardium. The results were compared with those obtained by using autologous temporalis fascia. Methods: The study group consisted of 52 patients with tympanic perforation. Twenty-nine patients were randomly selected for treatment with bovine pericardium and 23 for equine pericardium. A group of 14 patients was treated with autologous temporalis fascia. Results: Closure of the perforation was achieved i...
Meyers RA, Hermanson JW.The soleus muscle of horses is rather diminutive with respect to the overall size of adjacent synergist muscles in the hind limb of the horse. Whether or not such a muscle might be vestigial or may be providing some essential function has not been determined. We have studied the horse's soleus muscle using histochemical (ATPase), immunocytochemical (myosin isoform identification), and SDS-PAGE analysis to demonstrate that it is largely composed of 100% type I, presumed slow-twitch fibers. Only one soleus muscle studied (out of 13 adult horses) contained any type II muscle fibers. Given this co...
Staszyk C, Gasse H.The periodontal ligament (PDL) of the hypsodont cheek teeth of the horse meets specific requirements of tooth support: (1) to fix the tooth; (2) to withstand pressure and tension during the laterolateral mastication movement; (3) to restore the original tooth position. These requirements are assumed to be met by the periodontal collagen fiber apparatus and by the vascular system. Distinct fibro-vascular arrangements are described here in order to reveal the structural prerequisites for these distinct functions. Methods: Specimens from nine horses were processed for (1) collagen labeling with f...
