Experimental methods in equine research encompass a variety of techniques and procedures used to investigate physiological, behavioral, and health-related aspects of horses. These methods are designed to collect data that can enhance the understanding of equine biology and inform veterinary practices. Common experimental approaches include controlled trials, observational studies, and laboratory-based experiments. Techniques may involve the use of non-invasive imaging, biochemical assays, and physiological monitoring to assess parameters such as metabolic function, locomotion, and disease progression. This page compiles peer-reviewed research studies and scholarly articles that explore the application, development, and evaluation of experimental methods in the study of equine science.
Quinteros DD, García-López JM, Abuja GA, Tarkanian M, Maranda LS, Bubeck K, Kowaleski MP.To determine if the mechanical properties (strength and stiffness) of a new prototype 4.5 mm broad locking plate (NP-LP) are comparable with those of a traditional 4.5 mm broad limited-contact self compression plate (LC-SCP), and to compare the bending and torsional properties of the NP-LP and LC-SCP when used in osteotomized equine third metacarpal bones (MC3). Methods: The plates alone were tested in four-point bending single cycle to failure. The MC3-plate constructs were created with mid-diaphyseal osteotomies with a 1 cm gap. Constructs were tested in four-point bending single cycle to fa...
Rozanova SL, Rozanova ED, Nardid OA.Experimental data are presented which were obtained under comparative evaluation of influence of different freezing-thawing conditions on antioxidant properties of isolated proteins: human serum albumin, cytochrome c from the horse heart and glucose oxidase from Aspergillus niger. The observed protein antioxidant activity alterations are assumed to be a result of protein conformational changes. The character of freezing-thawing influence on the protein antioxidant activity depends on the molecular structure and cooling conditions.
Hanggi EB, Ingersoll JF.This study investigated lateral vision in horses (Equus caballus) for the first time from a behavioral point of view. Three horses were tested using a novel experimental design to determine the range of their lateral and caudolateral vision with respect to stimulus detection and discrimination. Real-life stimuli were presented along a curvilinear wall in one of four different positions (A, B, C, D) and one of two height locations (Top, Bottom) on both sides of the horse. To test for stimulus detection, the correct stimulus was paired against a control; for stimulus discrimination, the correct ...
Tee SY, Dart AJ, MacDonald MH, Perkins NR, Horadagoda N, Jeffcott LB.To evaluate the effect of collecting serial tracheal aspirate (TA) and bronchoalveolar lavage (BAL) samples on the cytological findings of subsequent fluid samples obtained from horses without clinical signs of respiratory disease. Methods: Experimental. Methods: Six healthy Standardbred horses. Methods: Endoscopically-guided TA samples, and BAL samples collected using the blind field technique were obtained from the six horses on days 1, 2, 3, 4, 5, 12, and 17. On day 17, horses were sampled three times: at baseline and at 2.5 h and 4 h apart. The differential cytology of the fluid samples co...
Renzi S, Lombardo T, Dotti S, Dessì SS, De Blasio P, Ferrari M.The advent of stem cells and stem cell-based therapies for specific diseases requires particular knowledge of laboratory procedures, which not only guarantee the continuous production of cells, but also provide them an identity and integrity as close as possible to their origin. Their cryopreservation at temperatures below -80°C and typically below -140°C is of paramount importance. This target can be achieved by incorporating high molar concentrations of cryoprotectant mixtures that preserve cells from deleterious ice crystal formation. Usually, dimethyl sulfoxide (DMSO) and animal proteins...
Nyman G, Grubb TL, Heinonen E, Frendin J, Edner A, Malavasi LM, Frostell C, Högman M.The study aimed to investigate the effect of varying pulse lengths of inhaled nitric oxide (iNO), and 2.5 hours of continuous pulse-delivered iNO on pulmonary gas exchange in anaesthetized horses. Methods: Experimental study. Methods: Six Standardbred horses. Methods: Horses received acepromazine, detomidine, guaifenesin, thiopentone and isoflurane in oxygen, were positioned in dorsal recumbency and were breathing spontaneously. iNO was on average pulsed during the first 20, 30, 43 or 73% of the inspiration in 15 minute steps. The pulse length that corresponded to the highest (peak) partial pr...
Gomes RG, Andrade ER, Lisboa LA, Ciquini A, Barreiros TR, Fonseca NA, Seneda MM.The objective was to evaluate the efficiency of phosphate-buffered saline (PBS) and Minimum Essential Medium (MEM) during the transport of equine preantral and antral follicles at various temperatures and incubation interval. Equine ovaries (n = 10) from an abattoir were cut into 19 fragments; one was immediately fixed in Bouin's solution (control) and the other fragments were placed in PBS or MEM solution at 4, 20, or 39 °C for 4, 12, or 24 h. After the respective incubation periods, all fragments were fixed in Bouin's solution for 24 h and then submitted to standard histologic analysis. In ...
Scarlet D, Budik S, Aurich C.A new device for storage and shipping of cell cultures--the Petaka G3 cell management device--was tested for its applicability for cooled-storage of equine semen. Semen from three stallions was processed with EquiPro extender either without antibiotics (three ejaculates per stallion) or with gentamicin (250 mg/l; three ejaculates per stallion). Semen was either stored at five (anaerobic conditions) or 15 °C (aerobic conditions) in syringes or cell culture devices. Total and progressive motility, as well as membrane integrity of spermatozoa, were evaluated from days 1 to 7 after collection wit...
Suagee JK, Corl BA.Culturing adipocytes enables fine control of experimental conditions and helps minimise animal use. This report describes an explant-based method for isolating stromal-vascular cells from equine adipose tissue that enables use of small amounts of tissue. Subcutaneous and mesenteric adipose tissues were harvested post mortem and stromal-vascular cells grown from explants, prior to testing the capacity of several differentiation media to induce lipid droplet formation and increase transcript abundance of adipocyte markers. Inclusion of rosiglitazone at 1 and 5 µmol/l concentrations, along with ...
LeBlanc MM, Giguère S, Lester GD, Brauer K, Paccamonti DL.Ascending placentitis results in premature birth and high foal mortality. By understanding how placentitis induces premature delivery, it may be possible to develop diagnostic markers and to delay premature delivery pharmacologically, thereby decreasing perinatal foal mortality. Objective: To identify relationships between bacterial infection, inflammation and premature parturition in mares with experimentally induced placentitis. Methods: Experiment 1: Concentrations of allantoic fluid prostaglandins (PGs) F2alpha and E2 were measured in 8 mares after intracervical inoculation with Streptococ...
Frellstedt L, McKenzie HC, Barrett JG, Furr MO.Endotoxemia is responsible for severe illness in horses. Individuals can become clinically unresponsive to the endotoxin molecule after an initial exposure; a phenomenon referred to as 'endotoxin tolerance' (ET). ET has been observed clinically in horses in vivo; however, cytokine expression associated with ET has not been investigated. The purpose of this study was to develop and validate a method for inducing ET in equine peripheral blood mononuclear cells (PBMC) in vitro, and to describe selected cytokine responses which are associated with ET. ET was induced by culturing cells with three c...
Pusterla N, Vannucci FA, Mapes SM, Nogradi N, Collier JR, Hill JA, Difrancesco M, White AM, Akana NK, Simonek G, Gebhart CJ.To determine the efficacy of an avirulent Lawsonia intracellularis vaccine in preventing proliferative enteropathy in weanling foals. Methods: 12 healthy weanling foals. Methods: Foals were randomly assigned to a vaccinated, nonvaccinated, or control group. Vaccinated foals received an avirulent porcine L intracellularis frozen-thawed vaccine intrarectally 60 and 30 days prior to experimental challenge. On day 1, vaccinated and nonvaccinated foals were challenged via nasogastric intubation with a virulent heterologous isolate of L intracellularis. Control foals were not challenged. Clinical ob...
McIlwraith CW, Frisbie DD, Kawcak CE.To assess clinical, radiographic, histologic, and biochemical effects of sodium pentosan polysulfate (NaPPS) administered IM for treatment of experimentally induced osteoarthritis in horses. Methods: 18 horses. Methods: Osteoarthritis was induced arthroscopically in 1 middle carpal joint of all horses. Nine horses received NaPPS (3 mg/kg, IM) on study days 15, 22, 29, and 36. Nine control horses received the same volume of saline (0.9% NaCl) solution IM on study days 15, 22, 29, and 36. Clinical, radiographic, gross, histologic, histochemical, and biochemical findings as well as findings of sy...
Fayrer-Hosken R, Stanley A, Hill N, Heusner G, Christian M, De La Fuente R, Baumann C, Jones L.The cellular effects of tall fescue grass-associated toxic ergot alkaloids on stallion sperm and colt testicular tissue were evaluated. This was a continuation of an initial experiment where the effects of toxic ergot alkaloids on the stallion spermiogram were investigated. The only spermiogram parameter in exposed stallions that was affected by the toxic ergot alkaloids was a decreased gel-free volume of the ejaculate. This study examined the effect of toxic ergot alkaloids on chilling and freezing of the stallion sperm cells. The effect of toxic ergot alkaloids on chilled extended sperm cell...
Yamanaka T, Nemoto M, Bannai H, Tsujimura K, Kondo T, Matsumura T, Muranaka M, Ueno T, Kinoshita Y, Niwa H, Hidari KI, Suzuki T.Since equine influenza A virus (H3N8) was transmitted to dogs in the United States in 2004, the causative virus, which is called canine influenza A virus (CIV), has become widespread in dogs. To date, it has remained unclear whether or not CIV-infected dogs could transmit CIV to horses. To address this, we tested whether or not close contact between horses and dogs experimentally infected with CIV would result in its interspecies transmission. Methods: Three pairs of animals consisting of a dog inoculated with CIV (10(8.3) egg infectious dose 50/dog) and a healthy horse were kept together in i...
Ronchi GF, Ulisse S, Rossi E, Franchi P, Armillotta G, Capista S, Peccio A, Di Ventura M, Pini A.Monovalent, inactivated and adjuvanted vaccines against African horse sickness, prepared with serotypes 5 and 9, were tested on guinea-pigs to select the formulation that offered the greatest immunity. The final formulation of the vaccines took into account the immune response in the guinea-pig and the inflammatory properties of two types of adjuvant previously tested on target animals. A pilot study was subsequently conducted on horses using a vaccine prepared with serotype 9. The vaccine stimulated neutralising antibodies from the first administration and, after the booster dose, 28 days lat...
Harris M, Nolen-Walston R, Ashton W, May M, Jackson K, Boston R.Blood samples banked for up to 1 month are typically used to perform pretransfusion testing in humans and small animals, but this has not been validated using blood from horses. Objective: Compatibility of equine blood samples is repeatable using fresh samples, and reproducible using donor blood samples stored for up to 4 weeks. Methods: Six healthy adult horses. Methods: Randomized, blinded experimental study. Immunologic compatibility of the blood of all horses was assessed using a major and minor saline agglutination and hemolysin crossmatch using blood samples refrigerated for 0-4 weeks an...
Harding PG, Smith RL, Barakzai SZ.To compare two approaches to performing the inferior alveolar nerve block in the horse and to evaluate the consistency of described topographical landmarks. Methods: Experimental cadaver model. Methods: Eleven cadaver heads were positioned to mimic a standing sedated horse and the position of the mandibular foramen approximated. The vertical approach to the approximate location of the mandibular foramen was undertaken and red dye was deposited. The angled approach was then undertaken and blue ink was used to identify it. The heads were then dissected to determine the location of the dye. Place...
Seo JP, Tsuzuki N, Haneda S, Yamada K, Furuoka H, Tabata Y, Sasaki N.A three dimensional scaffold is essential in mesenchymal stem cells (MSCs) delivery in cell-based therapy for facilitating cell adherence, migration, proliferation, and differentiation. The objectives of this study were to evaluate the possibility of β-tricalcium phosphate incorporated gelatin sponges (Gelatin/β-TCP sponge) as scaffolds for equine MSCs and to examine the effects of seeding density and seeding method on the proliferation of equine MSCs in the Gelatin/β-TCP sponges. Mononuclear cells and MSCs isolated from bone marrow were seeded into Gelatin/β-TCP sponges at different densi...
Love CC, Blanchard TL, Varner DD, Brinsko SP, Voge J, Bliss S, Sudderth K, Teague S, LaCaze K.An experiment was conducted to determine whether cooled semen quality could be maintained for a longer interval by conducting daily centrifugation of extended semen, with resuspension of the sperm pellet in fresh extender. Semen treatments included SP10NC and SP50NC which contained 10 and 50% seminal plasma, respectively, were not centrifuged (NC), and were stored at 4 to 7 °C for 96 h. Treatments SP10C and SP50C contained 10 and 50% seminal plasma, respectively, but were centrifuged (C) after 24, 48, and 72 h of cooled storage, with daily resuspension in fresh extender containing 10% seminal...
Morillo Rodriguez A, Balao da Silva C, Macías-García B, Gallardo Bolaños JM, Tapia JA, Aparicio IM, Ortega-Ferrusola C, Peña FJ.A total of 42 ejaculates were used in the experiment; six ejaculates per stallion, obtained from seven Pure Spanish stallions (PRE), were split and frozen in freezing media with different concentrations and combinations of cryoprotectant (CPA): (i) Cáceres (skim milk based extender) containing 2.5% glycerol (2.5GL), (ii) Cáceres containing 1.5% glycerol and 1.5% dimethylformamide (1.5%GL-1.5%DMFA), (iii) Cáceres extender supplemented with 1.5% glycerol and 2.5% dimethylformamide (1.5%GL-2.5%DMFA) and (iv) Cáceres extender supplemented with 4% dimethylformamide (4%DMFA). After at least 4 we...
Ceusters JD, Mouithys-Mickalad AA, de la Rebière de Pouyade G, Franck TJ, Votion DM, Deby-Dupont GP, Serteyn DA.To culture equine myoblasts from muscle microbiopsy specimens, examine myoblast production of reactive oxygen species (ROS) in conditions of anoxia followed by reoxygenation, and assess the effects of horseradish peroxidase (HRP) and myeloperoxidase (MPO) on ROS production. Methods: 5 healthy horses (5 to 15 years old). Methods: Equine skeletal myoblast cultures were derived from 1 or 2 microbiopsy specimens obtained from a triceps brachii muscle of each horse. Cultured myoblasts were exposed to conditions of anoxia followed by reoxygenation or to conditions of normoxia (control cells). Cell p...
Wahl K, Adams SB, Moore GE.To assess fetlock joint contamination with tissue debris and hair after arthrocentesis. Methods: Experimental. Methods: Fetlock joint tissues (n = 10 horses). Methods: Soft tissue flaps including the joint capsule were dissected from the dorsal fetlock joints of 7 anesthetized horses leaving an intact proximal base. Needles inserted through the tissue flaps were flushed into tissue cell culture plates and examined for debris. Studies were repeated on excised fetlock tissue preparations after being stored for 5 days. Variables included gauge and type of needle, insertion of spinal needles with ...
Boss MA, Chris Hammel P.The influence of proton diffusion on nuclear magnetic resonance (NMR) relaxation was investigated in the presence of horse spleen ferritin at 7 T. Binary mixtures of water and glycerol were used to control diffusion within the range of 0.6-2.0 × 10(-9)m(2)/s, which was confirmed by pulsed gradient techniques. The effect of chemical exchange by hydrolysis between water and glycerol on relaxation was characterized with Carr-Purcell-Meiboom-Gill (CPMG) dispersion experiments. The relaxation rate enhancement of the protons due to ferritin was found to be inversely proportional to the diffusion co...
Szóstek AZ, Siemieniuch MJ, Galvão AM, Lukasik K, Zieba D, Ferreira-Dias GM, Skarzynski DJ.Cell cultures are useful for determining the responses of specific cell types to various factors under controlled conditions and for obtaining a better understanding of in vivo physiologic processes. The aims of the present study were (i) to establish methodologies for isolation, culture and cryopreservation of equine endometrial epithelial and stromal cells; and (ii) to determine the effect of passage and cryopreservation on endometrial cell physiology, based on their basal and oxytocin (OT)-stimulated prostaglandin (PG) release. Epithelial and stromal cells were obtained by enzymatic digesti...
Dhar M, Neilsen N, Beatty K, Eaker S, Adair H, Geiser D.Two studies report variability in proliferation and limited adipocyte differentiation of equine peripheral blood-derived adult mesenchymal stem cells, thus casting doubt on their adipogenic potential. Peripheral blood can be a valuable source of adult mesenchymal stem cells if cell culture conditions permissive for their adherence, proliferation and differentiation are defined. Hyperbaric oxygen treatment has been reported to mobilise haematopoietic progenitor stem cells into the peripheral blood in humans and mice, but similar experiments have not been done in horses. Objective: To optimise c...
Rose MT.The objective of this study was to determine the effect of platelet derived growth factor BB (PDGF), epidermal growth factor (EGF), transforming growth factor β1 (TGFβ1), insulin like growth factor-1 (IGF-1) and fibroblast growth factor-2 (FGF-2) on the proliferation and migration of equine oral mucosa and leg skin fibroblast cell lines, using an in vitro scratch assay. Fibroblasts from the two sites were firstly grown to confluence and then an area of cells removed (cell void area). Cell migration alone (with the addition of the mitosis inhibitor mitomycin-C to the culture media) and prolif...
Hale BW, Goodrich LR, Frisbie DD, McIlwraith CW, Kisiday JD.To evaluate the effect of fibrin concentrations on mesenchymal stem cell (MSC) migration out of autologous and commercial fibrin hydrogels. Methods: Blood and bone marrow from six 2- to 4-year-old horses. Methods: Autologous fibrinogen was precipitated from plasma and solubilized into a concentrated solution. Mesenchymal stem cells were resuspended in fibrinogen solutions containing 100%, 75%, 50%, and 25% of the fibrinogen precipitate solution. Fibrin hydrogels were created by mixing the fibrinogen solutions with MSCs and thrombin on tissue culture plates. After incubation for 24 hours in cel...
Vigani A, Shih A, Queiroz P, Pariaut R, Gabrielli A, Thuramalla N, Bandt C.New volumetric variables of preload, such as total end-diastolic volume index (TEDVI) and active circulation volume index (ACVI) and central blood volume index (CBVI), may represent good indicators of preload and predictors of fluid responsiveness. During acute changes of intravascular volume these variables would allow a more accurate intervention. Objective: The aim of the present study was to investigate the changes in TEDVI, ACVI, CBVI in a juvenile model of hemorrhagic shock and resuscitation. Methods: Twelve anaesthetized ponies (3-8 months of age) were studied at normovolaemia (BASE), a...
Johnson CB, Bloomfield M, Taylor PM.To identify and characterize the effects of guaiphenesin (GGE) on the electroencephalogram during halothane anaesthesia. Methods: Prospective controlled study. Methods: Eight healthy Welsh mountain pony geldings between 5 and 9 years old and weighing between 270 and 330 kg (mean 301 kg). Methods: Anaesthesia was induced with thiopentone and maintained using halothane in oxygen. End tidal halothane was maintained above 0.75 and below 0.85%. The EEG was recorded continuously and a binaural broad band click stimulus was provided throughout the experiment at 6.1224 Hz. An infusion of 1500 mg GGE w...
Mills PC.The effects of three vehicles, phosphate-buffered saline (PBS), ethanol (50% in PBS w/w) and propylene glycol (50% in PBS w/w) on in vitro transdermal penetration of testosterone was investigated in the horse. Skin was harvested from the thorax of five Thoroughbred horses after euthanasia and stored at -20 degrees C until required. The skin was then defrosted and placed into Franz-type diffusion cells, which were maintained at approximately 32 degrees C by a water bath. Saturated solutions of testosterone, containing trace amounts of radiolabelled [14C]testosterone, in each vehicle were applie...
Hague BA, Honnas CM, Berridge BR, Easter JL.To evaluate the postoperative use of peritoneal lavage for prevention of experimentally induced intraabdominal adhesions in horses. Methods: Areas of serosal abrasion were created on the jejunum of 12 horses. Postoperatively, six horses had peritoneal lavage, and six horses did not (controls). The number of adhesions was determined at necropsy 2 weeks after surgery. Methods: 12 horses. Methods: Five sites of jejunal serosal abrasion were created in each horse. A 32 French thoracic catheter was placed into the right ventral aspect of the abdomen before closure of the abdominal incision. Treated...
Roberts MC, O'Boyle DA.Salmonella anatum was given orally to 8 horses on 11 occasions in doses ranging from 9.5 X 10(6) to 8.8 X 10(11) organisms. Four distinct syndromes were induced based upon clinical, laboratory and pathological findings: (1) asymptomatic; (2) moderate clinical signs with or without changes in faecal consistency; (3) fever, depression, anorexia with unstructured or diarrhoeic faeces; and (4) septicaemia with or without diarrhoea, and peripheral circulatory failure. All animals excreted the organism. The peak temperature preceded the onset of diarrhoea by 1 or 2 days. Changes in faecal consistenc...
Mendes MA, Chies JM, de Oliveira Dias AC, Filho SA, Palma MS.Most commercial recombinant proteins used as molecular biology tools, as well as many academically made preparations, are generally maintained in the presence of high glycerol concentrations after purification to maintain their biological activity. The present study shows that larger proteins containing high concentrations of glycerol are not amenable to analysis using conventional electrospray ionization mass spectrometry (ESI-MS) interfaces. In this investigation the presence of 25% (v/v) glycerol suppressed the signals of Taq DNA polymerase molecules, while 1% (v/v) glycerol suppressed the ...
Green MK, Johnston MV, Larsen BS.To elucidate the role of high mass accuracy in mass spectrometric peptide mapping and database searching, selected proteins were subjected to tryptic digestion and the resulting mixtures were analyzed by electrospray ionization on a 7 Tesla Fourier transform mass spectrometer with a mass accuracy of 1 ppm. Two extreme cases were examined in detail: equine apomyoglobin, which digested easily and gave very few spurious masses, and bovine alpha-lactalbumin, which under the conditions used, gave many spurious masses. The effectiveness of accurate mass measurements in minimizing false protein match...
Lee DH, Lee EB, Seo JP, Ko EJ.Despite vaccination, equine influenza virus (EIV) and equine herpesvirus (EHV) infections still cause highly contagious respiratory diseases in horses. Recently, concurrent vaccination with EIV and EHV was suggested as a new approach; however, there have been no reports of concurrent vaccination with recombinant canarypox EIV and inactivated EHV vaccines. In this study, we aimed to compare the EIV-specific immune responses induced by concurrent administrations of a recombinant canarypox EIV vaccine and an inactivated bivalent EHV vaccine with those induced by a single recombinant canarypox EIV...
Kruse CJ, Stern D, Mouithys-Mickalad A, Niesten A, Art T, Lemieux H, Votion DM.Equine atypical myopathy is a seasonal intoxication of grazing equids. In Europe, this poisoning is associated with the ingestion of toxins contained in the seeds and seedlings of the sycamore maple (Acer pseudoplatanus). The toxins involved in atypical myopathy are known to inhibit ß-oxidation of fatty acids and induce a general decrease in mitochondrial respiration, as determined by high-resolution respirometry applied to muscle samples taken from cases of atypical myopathy. The severe impairment of mitochondrial bioenergetics induced by the toxins may explain the high rate of mortality obs...
Pascoe RR.Twelve medicaments were tested for their efficacy in the treatment of Trichophyton equinum var. autotrophicum; povidone iodine, thiabendazole ointment, captan ointment and Burroughs Wellcome Ringworm Ointment gave satisfactory results but their usefulness may be limited for treatment of large numbers of horses. Aqueous washes containing 0.5% hexetidine or 0.3% chloramine-T did not prevent fungi being isolated from lesions for up to 7 days after treatment. Similarly neither etisazole nor thiabendazole suspension prevented fungi from being isolated from lesions for up to 15 days after treatment....
Sanz MG, Villarino N, Ferreira-Oliveira A, Horohov DW.Rhodococcus equi is a common cause of pneumonia in young foals worldwide and has considerable economic effects on the global equine industry. Despite ongoing efforts, no vaccine is currently available to prevent rhodococaal pneumonia. This is due, in part, to an incomplete understanding of the protective immune response to this bacterium. While antibodies to VapA, a lipoprotein produced by virulent R. equi, are useful in differentiating antibody production in response to pathogenic versus non-pathogenic strains, the significance of the humoral response of foals to this lipoprotein remains poor...
Gardner AK, van Eps AW, Watts MR, Burns TA, Belknap JK.Supporting limb laminitis (SLL) is a devastating sequela to severe unilateral lameness in equine patients. The manifestation of SLL, which usually only affects one limb, is unpredictable and the etiology is unknown. A novel, non-painful preferential weight bearing model designed to mimic the effects of severe unilateral forelimb lameness was developed to assess lamellar signaling events in the supporting limb (SL). A custom v-shaped insert was attached to the shoe of one forelimb to prevent normal weight bearing and redistribute weight onto the SL. Testing of the insert using a custom scale pl...
Ferreira JC, Filho LFN, Boakari YL, Canesin HS, Thompson DL, Lima FS, Meira C.The aim of the current project was to characterize the luteal vascularity and the plasma concentrations of progesterone (P4), prolactin (PRL) and 13,14-dihydro-15-keto-PGF (PGFM) in mares with luteal disturbances during early and mid-diestrus. In Experiment 1, twenty-one mares were treated with 2 mL of 0.9% NaCl, or 1 mg Dinoprost, or 10 mg Dinoprost on day two after ovulation (Control-D2, 1/10PGF-D2 and PGF-D2 groups, respectively; n = 7 mares/group). In Experiment 2, similar treatments were performed eight days post-ovulation using a different cohort of 21 mares (Control-D8, 1/10PGF-D8 ...
Nolen-Walston RD, Norton JL, Navas de Solis C, Underwood C, Boston R, Slack J, Dallap BL.Central venous pressure (CVP) is used in many species to monitor right-sided intravascular volume status, especially in critical care medicine. Objective: That hypohydration in adult horses is associated with a proportional reduction in CVP. Methods: Ten healthy adult horses from the university teaching herd. Methods: In this experimental study, horses underwent central venous catheter placement and CVP readings were obtained by water manometry. The horses were then deprived of water and administered furosemide (1 mg/kg IV q6h) for up to 36 hours. Weight, CVP, vital signs, PCV, total protein (...
Lewis SR, Ellison SP, Dascanio JJ, Lindsay DS, Gogal RM, Werre SR, Surendran N, Breen ME, Heid BM, Andrews FM, Buechner-Maxwell VA, Witonsky SG.Sarcocystis neurona is the most common cause of Equine Protozoal Myeloencephalitis (EPM), affecting 0.5-1% horses in the United States during their lifetimes. The objective of this study was to evaluate the equine immune responses in an experimentally induced Sarcocystis neurona infection model. Neurologic parameters were recorded prior to and throughout the 70-day study by blinded investigators. Recombinant SnSAG1 ELISA for serum and CSF were used to confirm and track disease progression. All experimentally infected horses displayed neurologic signs after infection. Neutrophils, monocytes, an...
Martoriati A, Duchamp G, Gérard N.Paracrine factors have significant effects during folliculogenesis. Because of various morphological features, the mare is a convenient model to study in vivo the effects of factors involved in periovulatory events. In the present work, epidermal growth factor (EGF; experiment 1, n = 49 mares) and interleukin-1beta and interleukin-1RA (IL-1beta and IL-1RA, respectively; experiment 2, n = 80 mares) were injected intrafollicularly to evaluate the influence of these factors on in vivo maturation of equine preovulatory follicles. A transvaginal ultrasound-guided injection was performed when the di...
Vogelsang MM, Kreider JL, Bowen MJ, Potter GD, Forrest DW, Kraemer DC.A series of experiments was conducted to develop a procedure for consistent, repeatable collection of oocytes from the preovulatory follicle of the mare. In one experiment, in situ follicular aspiration with a needle and syringe was performed on 19 mares. From 37 aspirations, four oocytes were recovered (10% recovery rate). In a second experiment, ovaries were visualized via standing flank laparotomy during which two different aspiration techniques were used. Use of a needle and syringe as in the first experiment resulted in successful oocyte recovery in one of seven (14%) attempts. Aspiration...
James S, Schuijers J, Daffy J, Cook J, Samiric T.Fluoroquinolones are an effective, broad-spectrum antibiotic used to treat an array of bacterial infections. However, they are associated with an increased risk of tendinopathy and tendon rupture even after discontinuation of treatment. This condition is known as fluoroquinolone-associated tendinopathy, the underlying mechanisms of which are poorly understood. While many factors may be involved in the pathophysiology of tendinopathies in general, changes in tenocyte metabolism and viability, as well as alteration of proteoglycan metabolism are prominent findings in the scientific literature. T...
Honkanen MKM, Mohammadi A, Te Moller NCR, Ebrahimi M, Xu W, Plomp S, Pouran B, Lehto VP, Brommer H, van Weeren PR, Korhonen RK, Töyräs J....Post-traumatic osteoarthritis is a frequent joint disease in the horse. Currently, equine medicine lacks effective methods to diagnose the severity of chondral defects after an injury. Objective: To investigate the capability of dual-contrast-enhanced computed tomography (dual-CECT) for detection of chondral lesions and evaluation of the severity of articular cartilage degeneration in the equine carpus ex vivo. Methods: Pre-clinical experimental study. Methods: In nine Shetland ponies, blunt and sharp grooves were randomly created (in vivo) in the cartilage of radiocarpal and middle carpal joi...
McCarty CA, Thomason JJ, Gordon K, Hurtig M, Bignell W.To add to the existing data on impact loading of the metacarpophalangeal (MCP) joint as a precursor to assessing the potential role of impact in joint disease. Objective: To examine the effect of impact loading on contact areas of the first phalanx (P1) and proximal sesamoids (PS) with the third metacarpal (McIII) under 3 hoof-strike conditions (toe-first, flat, heel-first). Methods: Randomised, repeated controlled experiment using cadaver material. Methods: Eight cadaver limbs were subjected to randomised, repeated controlled trials where the hoof was struck by a pendulum impact machine (impa...
Burrows GE.Repeated exposure of ponies in Escherichia coli endotoxin resulted in attenuation of the packed cell volume, beta-glucuronidase, capillary refill time and neutrophil responses usually accompanying endotoxin administration. An overall decrease in severity of clinical response including reduced mortality was also apparent in ponies with repeated endotoxin exposure. Modification of the febrile response was not observed in any of the experimental groups.
Higgins AJ, Lees P.The presence of cyclooxygenase products of arachidonic acid metabolism in carrageenin-induced inflammatory exudate was investigated in ponies using two models. In the first model, an inflammatory response was stimulated by injecting carrageenin into subcutaneously implanted polypropylene tissue cages and exudates were collected at five predetermined times between 3 and 48 h. In the second model, exudates were harvested at 6, 12 and 24 h from carrageenin-impregnated polyester sponges which had also been inserted beneath the skin. Prostaglandin (PG) E2, thromboxane (TX) B2 and the stable breakdo...
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 ...
Cheetham J, Nixon AJ.To identify sites for arthroscopic access to the palmar aspects of the antebrachiocarpal (AC) and middle carpal (MC) joints, and describe visible carpal bone surfaces for each approach. Methods: Prospective experimental study. Methods: Equine carpi: 16 cadavers, 8 live horses. Methods: A latex model was used to identify possible sites for arthroscopic access to the palmar aspects of the AC and MC joints. Carpi (n = 24) were examined arthroscopically and arthroscopic access sites and visible carpal bone surfaces were described. Results: Arthroscopic approaches and instrument portals were develo...
Boulanger P, Bannister GL, Ruckerbauer GM, Corner AH.Clinical field cases of equine infectious anemia were studied and the disease was reproduced experimentally in horses. Attempts were made to adapt the complement-fixation test to the detection of antibodies in the serum of infected animals and to the demonstration of antigens in tissue extracts.A moderate complement-fixing antibody response was demonstrated in the serum of horses shortly after primary exposure to the infectious agent. However, this reactivity was of short duration and occurred with normal as well as with infected saline tissue extracts. It was therefore concluded that this rea...
Kitai Y, Shirafuji H, Kanehira K, Kamio T, Kondo T, Konishi E.West Nile virus (WNV) and Japanese encephalitis (JE) virus are distributed separately in the world with some exceptions. There is a concern that WNV may invade into Asia where JE virus exists. On and after such invasion, any differential diagnosis could be complicated by serological crossreactivities. We previously demonstrated experimentally using horses infected with WNV that preimmunization with inactivated JE vaccine considerably affected the ability of neutralization tests and immunoglobulin M (IgM) antibody-capture enzyme-linked immunosorbent assay (ELISA) to diagnose WNV infection. Here...
Epstein V.Hyperkalaemia affected the equine myocardium. The minimum plasma potassium concentration required to induce electrocardiographic changes was 6.2 mmol/litre and severe cardiotoxic effects were observed at levels of 8.0 to 10.1 mmol/litre in this experimental situation. The most consistent sign of hyperkalaemia was broadening and flattening of the P wave, which was generally associated with a change in T waves in the chest lead from negative to positive. The more pronounced the hyperkalaemia, the less pronounced the P wave and the more peaked positive the T wave. Severe hyperkalaemia was associa...
Brunsting J, Dumoulin M, Oosterlinck M, Haspeslagh M, Lefère L, Pille F.Conventional shoeing restricts heel movement, which may have a negative effect on the orthopaedic health of the horse. A randomised crossover experimental study using noninvasive techniques was performed to compare the mediolateral heel movement in barefoot horses, horses shod with a conventional toe clipped shoe and with a new type of shoe with a split toe. In eight horses, 16 forelimbs were tested barefoot, shod with a conventional shoe and with the split-toe (ST) shoe, in random order. A displacement sensor was secured on the heels and measurements were collected continuously at a frequency...
Douglas RH, Ginther OJ.In experiment 1, seven groups of pony mares (2 or 3/group) were given either no injections (controls), or 5 (5X) or 10 (10X) daily subcutaneous (SC) injections of 1.25 mg PGF2alpha beginning on days 1, 7 or 13 post-ovulation. Compared to controls (24.5 days), the interovulatory interval was longer (P less than ..05) for day 7, 10X (33.5 days) and day 13, 10X mares (49.0 days) but was not different for the remaining groups. In experiment 2, nine groups of pony mares (4/group) were given either no injections (controls) or 1 (1X) or 10 (10X) daily SC injections of 1.25 mg PGF2alpha beginning on d...
Cogswell AM, Johnson PJ, Adams HR.To test the hypothesis that endothelium-derived nitric oxide modulates vasomotor reactivity in equine digital arteries. Methods: Digital arteries were isolated from adult horses, and their vasodilator properties were examined in an in vitro controlled environment. Methods: Five adult horses (1 gelding, 4 mares) without evidence of hoof or vascular disease were studied. Methods: Arterial rings with or without endothelium were exposed to endothelium-dependent vasodilator drugs in the presence or absence of a pharmacologic inhibitor of the enzyme nitric oxide synthase. Results: Vasodilator effect...
Cartmill JA, Thompson DL, Storer WA, Crowley JC, Huff NK, Waller CA.Three experiments tested the hypotheses that daily cortisol rhythm, feeding time, and/or insulin infusion affect(s) leptin secretion in stallions. Ten mature stallions received ad libitum hay and water and were fed a grain concentrate once daily at 0700. In Exp. 1, stallions received either a single injection of dexamethasone (125 microg/kg BW i.m.; n = 5) or vehicle (controls; n = 5) at 0700 on d -1. Starting 24 h later, blood samples were collected every 2 h for 36 h via jugular venipuncture. Cortisol in control stallions varied (P < 0.01) with time, with a morning peak and evening nadir;...
