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.
Parente EJ.Recurrent laryngeal neuropathy appears to be a simple problem that should have a simple solution, yet the complexity and dynamic nature of laryngeal function is underappreciated. This review highlights the challenges and accomplishments that work towards that greater understanding of what is necessary to find a successful solution.
Schwinghamer R, Massolo A, Knight C, Klein C.This study evaluated equine endometrial explants following 12, 24, and 48 hr in culture. Measurement of an indicator of cell death in explant supernatant, light microscopy, and gene expression of biomarkers of endometrial function and cellular stress were used to compare the effect of six different media on explant viability and morphology. Viability of explants was assessed indirectly through measuring LDH activity in the culture supernatant. Regardless of culture medium composition, a significant increase in LDH activity was observed within 12 hr of culture, indicating occurrence of cell dam...
Legnani S, Zini E, Roccabianca P, Funiciello B, Zanna G.Dermoscopy is a diagnostic tool that has been introduced into small animal dermatology for the evaluation of hair and the skin surface. To the best of the authors' knowledge, the use of this technique on horses and the dermoscopic appearance of equine hair and skin have yet to be reported. Objective: To assess the feasibility of dermoscopy, and to describe hair and skin surface features of healthy warmblood horses. Methods: Thirty four client-owned, healthy adult horses. Methods: Six body regions (head, neck, dorsal thorax, ventral thorax, croup and mane) were examined with a smartphone-attach...
Hopster K, Wittenberg-Voges L, Kästner SBR.To investigate the effects of a xylazine infusion during isoflurane anesthesia on global perfusion parameters and gastrointestinal oxygenation and microperfusion, 8 adult warmblood horses were sedated with xylazine and anesthesia induced with midazolam and ketamine. Horses were mechanically ventilated during anesthesia. After 3 h of stable isoflurane anesthesia (FIso 1.3 Vol %), a xylazine infusion with 1 mg/kg body weight (BW) per hour was started for 1 h and then stopped. Before, during, and after xylazine infusion, heart rate (HR), arterial blood pressure (MAP), cardiac output (CO), central...
Fernandes CB, Loux SC, Scoggin KE, Squires EL, Troedsson MH, Esteller-Vico A, Ball BA.The cervix is a dynamic structure that undergoes dramatic changes during the estrous cycle, pregnancy and parturition. It is well established that hormonal changes, including estrogens, progestogens and prostaglandins, regulate the expression of key proteins involved in cervical function. The arachidonic acid cascade is important in the remodeling and relaxation of the cervix in the days preceding parturition. Despite the complexity of this mechanism, regulation of cervical function has received little study in the mare. Therefore, the objective of this study was to compare the expression of e...
Faramarzi B, Lantz L, Lee D, Khamas W.The digital cushion (DC) plays a role in absorbing and dampening forces applied to the foot and therefore supports internal structures such as navicular bone; yet, its architecture is not well-known. The goal of this study was to characterize the microanatomical structure of the DC in horses with clinically sound hooves. Both forefeet from the cadavers of 12 adult Quarter horses were cut and sectioned and samples of the following 4 regions of the DC were obtained: axial proximal (AxProx), axial distal (AxDis), abaxial lateral (AbxLat), and abaxial medial (AbxMed). The samples were processed an...
White SH, Warren LK, Li C, Wohlgemuth SE.We tested the hypothesis that, similar to humans and rodents, exercise training would enhance mitochondrial (Mt) biogenesis and function in skeletal muscle of young horses. Twenty-four Quarter Horse yearlings were randomly assigned to either submaximal exercise training or no forced exercise (untrained). Biopsies were collected from the gluteus medius and triceps brachii before and after 9 wk of treatment. Citrate synthase activity was lower (P < 0.0001) and cytochrome c oxidase activity per Mt unit was higher (P < 0.0001) in gluteus compared to triceps, but neither changed over ...
Rui BR, Angrimani D, Bicudo LC, Losano J, Nichi M, Pereira R.Sperm DNA fragmentation is a condition that interferes directly in the reproductive efficiency. Currently, there are several methods for assessing the sperm DNA integrity, such as Alkaline Comet, TUNEL and Sperm Chromatin Structure Assay. However, many of these techniques are laborious and require high-precision equipment. Thus, the development of new techniques can optimize the evaluation of sperm DNA damage. Therefore, the aim of this study was to standardize the toluidine blue (TB) stain technique for the analysis of DNA fragmentation of dog, cat, bull, stallion and ram spermatozoa. For thi...
Echeverria KO, Lascola KM, Giguère S, Foreman JH, Austin SA.OBJECTIVE To determine pharmacokinetics and pulmonary disposition of minocycline in horses after IV and intragastric administration. ANIMALS 7 healthy adult horses. PROCEDURES For experiment 1 of the study, minocycline was administered IV (2.2 mg/kg) or intragastrically (4 mg/kg) to 6 horses by use of a randomized crossover design. Plasma samples were obtained before and 16 times within 36 hours after minocycline administration. Bronchoalveolar lavage (BAL) was performed 4 times within 24 hours after minocycline administration for collection of pulmonary epithelial lining fluid (PELF) and BAL ...
Al-Haidar A, Moula N, Leroux A, Farnir F, Deleuze S, Sandersen C, Amory H.The aim of this study was to establish echocardiographic reference values for the equine species using allometric regression equations based on body weight (BW) and thoracic circumference (TC). Methods: A total of 239 horses or ponies were studied, including 65 warmbloods, 33 Standardbreds, 41 Thoroughbreds, 32 Arabian horses, 28 draft horses, and 40 ponies aged from 1 day to 30 years, weighing from 18 to 890 kg, with no evidence of cardiac disease. Methods: For each horse or pony, a two-dimensional and M-mode echocardiography was performed. Within each breed, the relationships between BW or ...
Meneses CS, Müller HY, Herzberg DE, Uberti B, Bustamante HA, Werner MP.The role of glial cells in pain modulation has recently gathered attention. The objective of this study was to determine healthy spinal microglia and astrocyte morphology and disposition in equine spinal cord dorsal horns using Iba-1 and GFAP/Cx-43 immunofluorescence labeling, respectively. Five adult horses without visible wounds or gait alterations were selected. Spinal cord segments were obtained post-mortem for immunohistochemical and immunocolocalization assays. Immunodetection of spinal cord dorsal horn astrocytes was done using a polyclonal goat antibody raised against Glial Fibrillary ...
MacNicol JL, Lindinger MI, Pearson W.Exercise is a physiological stress resulting in reactive oxygen species and inflammatory mediators, the accumulation of which are thought to contribute to degenerative articular diseases. The horse is of particular interest in this regard as equine athletes are frequently exposed to repetitive bouts of high-intensity exercise. The purpose of this study was to provide a detailed description of the response of articular and systemic oxidative and inflammatory biomarkers following high-intensity, exhaustive exercise in horses. A group of horses (Ex) underwent repeated bouts of high-intensity exer...
Dirikolu L, Waller P, Waguespack ML, Andrews FM, Keowen ML, Gaunt SD.This study evaluated the usage of Beckman Coulter AU680 analyzers for measurement of TCO in horse serum, and the effect of sodium bicarbonate administrations on serum TCO levels in resting horses. Treatment of horses with sodium bicarbonate did not result in any adverse events. Mean TCO concentration was significantly higher from 1 to 8 h in the sodium bicarbonate-treated horses compared to the untreated controls. Within an hour, administration of sodium bicarbonate increased the TCO level from 31.5 ± -2.5 (SD) to 34.0 ± 2.65 (SD) mmol/L and at 2-8 h post-administration, the TCO l...
Lanata A, Guidi A, Valenza G, Baragli P, Scilingo EP.This study focuses on the analysis of human-horse dynamic interaction using cardiovascular information exclusively. Specifically, the Information Theoretic Learning (ITL) approach has been applied to a Human-Horse Interaction paradigm, therefore accounting for the nonlinear information of the heart-heart interplay between humans and horses. Heartbeat dynamics was gathered from humans and horses during three experimental conditions: absence of interaction, visual-olfactory interaction, and brooming. Cross Information Potential, Cross Correntropy, and Correntropy Coefficient were computed to qua...
Medica P, Bruschetta G, Cravana C, Ferlazzo A, Fazio E.The objective of current study was to evaluate the effect of transportation stress on the circulating adrenaline (A), noradrenaline (NA) and dopamine (DA) responses of stallions, according to the different distances. Forty-two stallions were studied before and after road transportation of 100, 200 and 300km, for a period of 1-3h. An increase in plasma A after 100km (P<0.001) was observed. A similar result was seen in plasma NA after 100km (P<0.001), and 300km (P<0.001). Increases in plasma DA after 100 and 200km (P<0.0001) were observed, with a decrease after 300km (P<0.0001). S...
Legacki EL, Corbin CJ, Ball BA, Scoggin KE, Stanley SD, Conley AJ.Steroidogenic enzymes in placentas shape steroid hormone profiles in the maternal circulation of each mammalian species. These include 3β-hydroxysteroid dehydrogenase/Δ5-4 isomerase (3βHSD) and 17α-hydroxylase/17,20-lyase cytochrome P450 (P450c17) crucial for progesterone and androgen synthesis, respectively, as well as aromatase cytochrome P450 (P450arom) that converts Δ4-androgens to estrogens. 5α-reductase is another important enzyme in equine placentas because 5α-dihydroprogesterone (DHP) sustains pregnancy in the absence of progesterone in the second half of equine pregnancy. DHP a...
Hopster K, Ambrisko TD, Kästner SBR.To compare the lithium dilution method for cardiac output (LiDCO) and bolus-thermo-dilution (BTD) measurements before and during infusion of dobutamine, dopamine, phenylephrine, or noradrenaline at 2 different doses in anesthetized horses and to examine the correlation between sensor voltages (saline-blood exposed) and possible measurement errors. Methods: Prospective experimental study. Methods: University teaching hospital. Methods: Nine Warmblood horses. Methods: Following 90 minutes of equilibration, 3 different doses of dobutamine (0.5-3 μg/kg/min), dopamine (1-5 μg/kg/min), phenylephri...
Textor JA, Clark KC, Walker NJ, Aristizobal FA, Kol A, LeJeune SS, Bledsoe A, Davidyan A, Gray SN, Bohannon-Worsley LK, Woolard KD, Borjesson DL.Distal extremity wounds are a significant clinical problem in horses and humans and may benefit from mesenchymal stem cell (MSC) therapy. This study evaluated the effects of direct wound treatment with allogeneic stem cells, in terms of gross, histologic, and transcriptional features of healing. Three full-thickness cutaneous wounds were created on each distal forelimb in six healthy horses, for a total of six wounds per horse. Umbilical cord-blood derived equine MSCs were applied to each wound 1 day after wound creation, in one of four forms: (a) normoxic- or (b) hypoxic-preconditioned cells ...
Siwinska N, Zak A, Baron M, Cylna M, Borowicz H.The aim of this study was to determine the normal location, wall thickness and motility of the right dorsal colon in adult ponies and miniature horses. The abdominal ultrasonography examination was performed in a study group consisting of 23 ponies and miniature horses and in a control group comprising ten Thoroughbred horses. The procedure was performed in unsedated standing animals. The location and the thickness of the right dorsal colonic wall was examined on the right side of the abdomen between the 10th and the 14th intercostal space. The contractility was recorded in the 12th intercosta...
Bonilla-Correal S, Noto F, Garcia-Bonavila E, Rodríguez-Gil JE, Yeste M, Miro J.Aquaporins (AQPs) are transmembrane proteins found in all cells and are responsible for the transport of water and small solutes. While these proteins have been found in the spermatozoa of humans, rodents, pigs and cattle, where not only do they play a role for the regulation of sperm volume but are also related with the sperm resilience to withstand freeze-thawing procedures, their presence in stallion sperm is yet to be reported. Therefore, the objectives of this work were as follows: (i) to determine whether AQP3, AQP7 and AQP11 are present in stallion sperm and (ii) to investigate whether ...
Miyata H, Itoh R, Sato F, Takebe N, Hada T, Tozaki T.Variants of the Myostatin gene have been shown to have an influence on muscle hypertrophy phenotypes in a wide range of mammalian species. Recently, a Thoroughbred horse with a C-Allele at the g.66493737C/T single-nucleotide polymorphism (SNP) has been reported to be suited to short-distance racing. In this study, we examined the effect of the Myostatin SNP on muscle fiber properties in young Thoroughbred horses during a training period. To investigate the effect of the Myostatin SNP on muscle fiber before training, several mRNA expressions were relatively quantified in biopsy samples from the...
Pereira RCDF, De La Côrte FD, Brass KE, da Silva Azevedo M, Gallio M, Cantarelli C, Dau SL, Cezar AS, Inkelmann MA.Wounds localized on the distal limbs in horses are difficulty healing. No studies have been conducted to evaluate homologous platelet-rich plasma (PRP) in horses. The aim of this study was to evaluate the effect upon applying autologous PRP, homologous PRP, and autologous PRP gel on the wound healing process of wounds on the distal limb of horses. To study a possible correlation between the platelet count and wound healing time, four skin wounds of 4 cm2 were surgically created on the dorsolateral aspect of the third metacarpus in eight healthy adult horses. Each skin wound was randomly treate...
Lee JY, Na HJ, Kim HM, Lee SC, Lee JY, Chung CP, Seol YJ, Park YJ.The purpose of this study was to evaluate the efficacy and safety of equine-derived bone matrix as a carrier for recombinant human platelet-derived growth factor BB (rhPDGF-BB) versus beta-tricalcium phosphate (β-TCP) for the treatment of intraosseous periodontal defects in adult patients. This study was performed on 32 adults with advanced periodontal disease. Eligible subjects were randomized in 1:1 ratio into a test (rhPDGF-BB-coated equine-derived bone matrix) or control group (rhPDGF-BB-coated β-TCP). Probing pocket depth (PD), clinical attachment level (CAL), gingival recession (GR), a...
Thu VT, Kim HK, Han J.Numerous animal cardiac exercise models using animal subjects have been established to uncover the cardiovascular physiological mechanism of exercise or to determine the effects of exercise on cardiovascular health and disease. In most cases, animal-based cardiovascular exercise modalities include treadmill running, swimming, and voluntary wheel running with a series of intensities, times, and durations. Those used animals include small rodents (e.g., mice and rats) and large animals (e.g., rabbits, dogs, goats, sheep, pigs, and horses). Depending on the research goal, each experimental protoc...
White SH, Wohlgemuth S, Li C, Warren LK.Exercise is known to promote mitochondrial biogenesis in skeletal muscle as well as enhance mitochondrial function and efficiency in human and rodent models. These adaptations help to decrease exercise-associated production of reactive oxygen species, which can negatively affect health and performance if antioxidant mechanisms are overwhelmed. Little is known about the adaptations of mitochondria in response to exercise training in the growing horse or if supplementation with a dietary antioxidant can improve mitochondrial function. To evaluate the separate and combined effects of selenium (Se...
Jäderkvist Fegraeus K, Hirschberg I, Árnason T, Andersson L, Velie BD, Andersson LS, Lindgren G.The Icelandic horse is a breed known mainly for its ability to perform the ambling four-beat gait 'tölt' and the lateral two-beat gait pace. The natural ability of the breed to perform these alternative gaits is highly desired by breeders. Therefore, the discovery that a nonsense mutation (C>A) in the DMRT3 gene was the main genetic factor for horses' ability to perform gaits in addition to walk, trot and canter was of great interest. Although several studies have demonstrated that homozygosity for the DMRT3 mutation is important for the ability to pace, only about 70% of the homozygous mutan...
Holcomb KE.Shade or shelter as protection from extremes of weather is required for horses at agricultural research and teaching facilities and is recommended or required by many states, professional organizations, and industry groups. The focus of this paper is the recent research on the responses of horses to hot, sunny weather, which has begun to provide scientific evidence that characterizes how and when shade is used and any benefits shade confers on horses. These behavioral and physiological findings support provision of shade as a resource for thermal comfort and the expression of normal behavior t...
Wynn MAA, Esteller-Vico A, Legacki EL, Conley AJ, Loux SC, Stanley SD, Curry TE, Squires EL, Troedsson MH, Ball BA.During the latter half of gestation in mares, there is a complex milieu of pregnanes in peripheral blood. Progesterone concentrations are often assessed by immunoassay during late gestation as a measure of pregnancy well-being; however, interpretation of results is complicated by the numerous cross-reacting pregnanes present in high concentrations during late gestation. Further, many mares are supplemented with an exogenous progestin, altrenogest, which may also cross-react with existing assays and further confound interpretation. The objectives of this study were: 1) to compare differences in...
Whitesell K, Stefanovski D, McDonnell S, Turner R.The stallion Breeding Soundness Examination (BSE), as proposed by the Society for Theriogenology, recommends that a stallion produce a minimum of one billion progressively motile, morphologically normal sperm (PMMNS) in the second of two ejaculates collected 1 h apart to be classified as a Satisfactory Prospective Breeder. With this in mind, the first objective of this study was to determine if the classification outcome of the traditional BSE differs depending on the methods used to evaluate sperm motility, morphology and concentration. We hypothesized that application of Computer Assisted ...
Crowell-Davis SL.The mare is seasonally polyestrus, having an anovulatory period during the short light days of late fall and early winter, and beginning to ovulate as the days become longer during the winter. The complete estrus cycle is typically about 3 weeks, with 5 to 7 days of estrus and approximately 2 weeks of diestrus. When a mare lives within the natural social structure of the horse, i.e. a family band with several adult mares and one or more stallions, estrus is characterized by repeatedly approaching the stallion, frequent urination, deviating the tail away from the perineum, and standing still wi...
Durgam SS, Stewart AA, Pondenis HC, Yates AC, Evans RB, Stewart MC.To compare in vitro expansion of equine tendon- and bone marrow-derived cells with fibroblast growth factor-2 (FGF-2) supplementation and sequential matrix synthesis with pulverized tendon and insulin-like growth factor-I (IGF-I). Methods: Cells from 6 young adult horses. Methods: Progenitor cells were expanded in monolayers with FGF-2, followed by culture with autogenous acellular pulverized tendon and IGF-I for 7 days. Initial cell isolation and subsequent monolayer proliferation were assessed. In pulverized tendon cultures, cell viability and expression of collagen types I and III and carti...
McIver VC, Tsang AS, Symonds NE, Perkins NR, Uquillas E, Dart CM, Jeffcott LB, Dart AJ.Evaluate the effect of topical 1% cannabidiol on second intention wound healing in distal limb wounds of horses. Methods: Experimental. Methods: Six Standardbred horses. Methods: A total of five 2.5 cm × 2.5 cm full thickness skin wounds were created on the dorsomedial aspect of the metacarpi of 6 horses. Wounds were contaminated with faeces on the day of wound creation. Each wound was then assigned to a treatment group; compounded 1% cannabidiol in unique manuka factor (UMF) 5 manuka honey, UMF 5 manuka honey, UMF 20 manuka honey or saline. Each treatment was applied topically daily ...
Merlo B, Teti G, Mazzotti E, Ingrà L, Salvatore V, Buzzi M, Cerqueni G, Dicarlo M, Lanci A, Castagnetti C, Iacono E.Wharton's jelly (WJ) is an important source of mesenchymal stem cells (MSCs) both in human and other animals. The aim of this study was to compare human and equine WJMSCs. Human and equine WJMSCs were isolated and cultured using the same protocols and culture media. Cells were characterized by analysing morphology, growth rate, migration and adhesion capability, immunophenotype, differentiation potential and ultrastructure. Results showed that human and equine WJMSCs have similar ultrastructural details connected with intense synthetic and metabolic activity, but differ in growth, migration, a...
Beacham BE, Cooper PH, Buchanan CS, Weary PE.We describe four patients with panniculitis attributable to a combination of cold exposure and equestrian activities. All were young, healthy women who rode horses for at least two consecutive hours per day throughout the winter. Initially, several small, erythematosus, pruritic papules appeared on the superior-lateral portions of one or both thighs. During one week, the lesions progressed to indurated, red-to-violaceous,tender plaques and nodules. Studies for cryofibrinogens and cryoglobulins were negative. The histologic picture was that of a panniculitis with prominent inflammation of veins...
Roelvink ME, Goossens L, Kalsbeek HC, Wensing T.The analgesic and spasmolytic effects of dipyrone (Novalgin) (2500 mg/100 kg bodyweight) hyoscine-N-butylbromide (Buscopan) (20 mg/100 kg bodyweight) and a combination of both drugs were evaluated in a balloon-induced model of colic, using five ponies with caecal fistulae. The drugs were given intravenously and 0.9 per cent sodium chloride solution (5 ml/100 kg bodyweight) was used as a control. The physiological saline solution and dipyrone had no effect on caecal contractions. After the injection of hyoscine-N-butylbromide and the drug combination caecal contractions ceased within 30 seconds...
Staszyk C, Wulff W, Jacob HG, Gasse H.The objective of this study was to examine the spatial arrangement of the fiber apparatus of the equine periodontium which is supposed to meet two contrary requirements: (1) to attach the tooth firmly and elastically to the alveolar bone; and, to be appropriately remodeled and reconstructed in order to facilitate the prolonged eruption of the tooth. Specimens of periodontal ligament were obtained from the buccal and lingual/palatal aspects of the first molars from the maxilla and mandible of 12 horses. The animals were assigned to three age groups. Histological sections were prepared from thre...
Brama PA, Holopainen J, van Weeren PR, Firth EC, Helminen HJ, Hyttinen MM.We investigated the effects of exercise-induced loading on the collagen network of equine articular cartilage. Collagen fibril architecture at a site (1) subjected to intermittent high-intensity loading was compared with that of an adjacent site (2) sustaining continuous low-level load. From horses exposed to forced exercise (CONDEX group) or not (PASTEX group), the spatial parallelism of fibrils and the orientation angle between fibrils and the surface at depths 9 microm apart through cartilage from surface to tidemark were determined using polarized light microscopy, and expressed as paralle...
Dougherty DM, Lewis P.Using horses, we investigated three aspects of the stimulus control of lever-pressing behavior: stimulus generalization, discrimination learning, and peak shift. Nine solid black circles, ranging in size from 0.5 in. to 4.5 in. (1.3 cm to 11.4 cm) served as stimuli. Each horse was shaped, using successive approximations, to press a rat lever with its lip in the presence of a positive stimulus, the 2.5-in. (6.4-cm) circle. Shaping proceeded quickly and was comparable to that of other laboratory organisms. After responding was maintained on a variable-interval 30-s schedule, stimulus generalizat...
Leng J, Walton G, Swann J, Darby A, La Ragione R, Proudman C.The intestinal microbiota of the horse, an animal of huge economic and social importance worldwide, is essential to the health of the animal. Understanding the intestinal ecosystem and its dynamic interaction with diet and dietary supplements currently requires the use of experimental animals, with consequent welfare and financial constraints. Here, we describe the development and assessment, using multiple analytical platforms, of a three-vessel, continuous-flow, model of the equine hindgut. After inoculation of the model with fresh horse feces, the bacterial communities established in each ...
Eberhardt C, Amann B, Stangassinger M, Hauck SM, Deeg CA.Retinal Müller glial cells are of vital importance for maintaining a physiological environment within the retina. To this end, they provide highly specialized physiological properties to support neurons in structure, nutrition and metabolism. The purpose of this study was to isolate Müller cells from the equine retina, determine their characteristics and subsequently establish a stable equine Müller cell line (eqMC) that will provide a prerequisite for investigations on their physiological properties. Dissociated retinal cells were obtained from equine retinas by a papain digestion techniqu...
Russo D, Bombardi C, Grandis A, Furness JB, Spadari A, Bernardini C, Chiocchetti R.The distribution and chemical phenotypes of sympathetic and dorsal root ganglion (DRG) neurons innervating the equine ileocecal junction (ICJ) were studied by combining retrograde tracing and immunohistochemistry. Immunoreactivity (IR) for tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH), neuronal nitric oxide synthase (nNOS), calcitonin gene-related peptide (CGRP), substance P (SP), and neuropeptide Y (NPY) was investigated. Sympathetic neurons projecting to the ICJ were distributed within the celiac (CG), cranial mesenteric (CranMG), and caudal mesenteric (CaudMG) ganglia, as well ...
Catalán J, Llavanera M, Bonilla-Correal S, Papas M, Gacem S, Rodríguez-Gil JE, Yeste M, Miró J.The aim of this study was to evaluate whether red-light stimulation increases the longevity and resilience of cryopreserved stallion sperm to withstand post-thaw incubation for 120 min. Sixteen frozen straws of 0.5 mL from eight stallions were used. Samples were cryopreserved, thawed through incubation at 38 °C for 30 s and divided into the control and samples exposed to red-light using a triple LED photo-activation system (wavelength: 620-630 nm). Three irradiation protocols consisting of different light-dark-light intervals (1-1-1, 2-2-2 and 3-3-3 min) were tested. Sperm quality param...
Gamboa S, Ramalho-Santos J.Proteins implicated in the "SNARE hypothesis" for membrane fusion have been characterized in the acrosome of several mammalian species, and a functional role for these proteins during the acrosome reaction has been proposed. We have investigated the presence of SNAREs in equine sperm, using semen samples obtained from stallions with varying fertility. Immunocytochemical analysis revealed that members of different SNARE families can be detected on the acrosome of equine sperm, notably in the acrosomal cap and equatorial segment. These proteins include the t-SNARE syntaxin, the v-SNARE synaptobr...
Strand E, Braathen LC, Hellsten MC, Huse-Olsen L, Bjornsdottir S.The Icelandic horse is a pristine breed of horse which has a pure gene pool established more than a thousand years ago, and is approximately the same size as living and extinct wild breeds of horses. This study was performed to compare the length of the skeletal growth period of the "primitive" Icelandic horse relative to that reported for large horse breeds developed over the recent centuries. This information would provide practical guidance to owners and veterinarians as to when the skeleton is mature enough to commence training, and would be potentially interesting to those scientists inve...
Egerbacher M, Helmreich M, Probst A, König H, Böck P.Digital cushions were studied in horses with particular reference to vascularization, tissue constituents and matrix components. The cushions mainly resembled a network of coarse collagen bundles. The areas inbetween the bundles were replenished with loosely woven interstitial connective tissue, myxoid tissue, and fibrocartilage. Expected masses of fat lobules were missing: only solitary adipocytes or small groups of adipocytes were seen. Vascular supply to the cushions was remarkably poor. The mucinous myxoid matrix largely consisted of hyaluronan with little sulphated glycosaminoglycans. Myx...
Wilson B, Novakofski KD, Donocoff RS, Liang YX, Fortier LA.Telomere length and telomerase activity are important indicators of cellular senescence and replicative ability. Loss of telomerase is associated with ageing and the development of osteoarthritis. Implantation of telomerase-positive cells, chondrocytes, or stem cells expressing a normal chondrocyte phenotype is desired for cartilage repair procedures. The objective of this study was to identify at what age chondrocytes and at what passage bone marrow-derived mesenchymal stem cells (MSCs) become senescent based on telomerase activity. The effect of osteogenic protein-1 (OP-1) or interleukin-1α...
Art T, Lekeux P.The effects of training and detraining on ventilation during a standardised exercise test were investigated. Ten healthy Thoroughbred horses underwent 5 standardised treadmill exercise tests (SET): SET1, at the start of the experimental period; SET2, after 3 weeks acclimatisation; SET3, after 3 week of aerobic training; SET4 after 3 weeks of anaerobic (i.e. interval) training; and SET5, after 3 weeks of detraining. The SETs were carried out in an air-conditioned laboratory on a treadmill inclined at 6 degrees. Respiratory airflow, tidal volume (VT), respiratory frequency (RF) and expired minut...
Katila T.The uterus of domestic animals, including the horse, has a dual role in the interaction of the uterus and sperm. On one hand, uterine contractions carry sperm toward the oviduct, and on the other hand the uterus eliminates excessive sperm. The selection of sperm for the small numbers of "good" cells that gain access to the oviduct and for the majority of sperm that will be destroyed takes place in the uterus. The sperm-uterine interaction works both ways; sperm and seminal plasma also have several effects on the uterus. Sperm and seminal plasma probably provoke uterine contractions. Sperm indu...
Back W, Schamhardt HC, Hartman W, Barneveld A.In literature, it has been hypothesized that the concussion at impact in the equine forelimb is larger than that in the hind limb, and therefore, eventually more clinical lameness may develop in the distal portion of the forelimbs. As the functional anatomy of the distal forelimb and hind limb segments is similar, a study was undertaken to compare the kinematics of hoof and fetlock in the forelimbs and hind limbs. For this purpose, the trot of 24 clinically normal (sound) horses on a treadmill (4 m/s) was recorded, using modern gait analysis equipment. It appeared that vertical hoof velocity a...
Al-zi'abi MO, Watson ED, Fraser HM.Precise pharmacological control of the corpus luteum is important in the manipulation of the oestrous cycle in mares. Angiogenesis plays a key role in the growth and regression of the corpus luteum; therefore, influencing the vasculature of the corpus luteum may offer a novel method for controlling its lifespan. In the present study, changes in angiogenesis and vascular expression of endothelial growth factor (VEGF) were evaluated throughout the luteal phase and after PGF(2alpha)-induced luteolysis. Corpora lutea were collected from mares in the early luteal phase (days 3-4), mid-luteal phase ...
Sumner SM, Naskou MC, Thoresen M, Copland I, Peroni JF.Platelet preparations containing growth factors, attachment factors, and enzymes are appealing to enhance healing of injured tissues and as an alternative to xenogenic serum in cell culture media. Plateletpheresis is commonly used to collect platelets in human medicine but has not been validated in horses. Plateletpheresis to collect platelet concentrate was performed on six female, mixed breed, chemically restrained horses using commercially available apheresis equipment. Before and immediately after plateletpheresis, we performed physical examinations and collected blood for chemistry and co...
Bucci D, Giaretta E, Spinaci M, Rizzato G, Isani G, Mislei B, Mari G, Tamanini C, Galeati G.Alkaline phosphatase (AP) has been studied in several situations to elucidate its role in reproductive biology of the male from different mammalian species; at present, its role in horse sperm physiology is not clear. The aim of the present work was to measure AP activity in seminal plasma and sperm extracts from freshly ejaculated as well as in frozen-thawed stallion spermatozoa and to verify whether relationship exists between AP activity and sperm quality parameters. Our data on 40 freshly ejaculated samples from 10 different stallions demonstrate that the main source of AP activity is semi...
Bottagisio M, Pellegata AF, Boschetti F, Ferroni M, Moretti M, Lovati AB.Tendon ruptures and/or large losses remain to be a great clinical challenge and often require full replacement of the damaged tissue. The use of auto- and allografts or engineered scaffolds is an established approach to restore severe tendon injuries. However, these grafts are commonly related to scarce biocompatibility, site morbidity, chronic inflammation and poor biomechanical properties. Recently, the decellularisation techniques of allo- or xenografts using specific detergents have been studied and have been found to generate biocompatible substitutes that resemble the native tissue. This...
Clayton HM.The central body axis or core is a key component in controlling body posture and providing a stable platform for limb movements and generation of locomotor forces. Persistent dysfunction of the deep stabilizing muscles seems to be common in horses indicating a need for core training exercises to restore normal function. Core training should be performed throughout the horse's athletic career to maintain a healthy back and used therapeutically when back pain is identified. This article reviews the structure and function of the equine thoracolumbar spine with special reference to function, dysfu...
Couroucé A, Chatard JC, Auvinet B.The purpose of this study was to examine the relationship between V4 (velocity which results in a blood lactate concentration of 4 mmol/l), age and racing performance of Standardbred trotters and to establish V4 normal values to select good and poor performers. The specific influence of racing (RT) and training (T1 and T2) tracks was also examined. A total of 159 horses were divided into 5 age-groups from 2 to 6 and over and performed 330 standardised exercise tests of 3 steps performed at increasing speeds. The velocity of the horses was measured with a tachometer on the sulky. Blood lactate ...
Bisgaard M, Piechulla K, Ying YT, Frederiksen W, Mannheim W.Evidence was obtained to indicate that equine strains of organisms previously described as Actinobacillus suis or hemolytic variants of Actinobacillus equuli might constitute a separate group of organisms provisionally designated taxon 11. Four biovars were noticed within taxon 11. Selected DNA:DNA hybridizations support the classification of the mannitol positive biovar 2 of taxon 11 distinct from porcine A. suis. The final taxonomical position of taxon 11, however, has to await more detailed genetic studies including all biovars of taxon 11. A species name has not been suggested for the same...
Hall BG, Faunce W.The genes for utilization of cellobiose are normally cryptic in both laboratory strains and natural isolates of Escherichia coli. A survey of natural isolates of E. coli reveals that functional genes for cellobiose utilization, while rare, are present. The fraction of E. coli that utilized cellobiose ranged from less than 0.01% in human fecal samples to 7% in fecal samples obtained from horses. Samples obtained from sheep, cows, dogs, and pigs contained 0.1 to 0.5% cellobiose-positive E. coli. Neither the previously identified cel genes nor the bgl genes from E. coli K-12 were expressed during...
The objective of this study was to graft autologous mesenchymal stem cells (MSCs) at the site of surgical repair of a soft palate defect in an adult horse in an attempt to improve wound healing and to investigate whether the transplanted MSCs would integrate into the soft palate structure and participate in regeneration. Bone marrow was collected from an adult horse with a full-thickness soft palate defect. The MSCs were isolated, cultured in monolayers, and labeled with 5-bromo-2-desoxymidine (BrdU) and chloromethylbenzamido-DiI-derived (cm-DiI) before transplantation. The soft palate defect ...
