In vivo studies involving horses refer to research conducted within living organisms to understand various biological processes, disease mechanisms, and therapeutic interventions in equine species. These studies provide insights into the physiological and pathological responses of horses under natural conditions. In vivo research encompasses a range of investigations, including pharmacokinetics, disease modeling, and the evaluation of treatment efficacy. It often involves the use of controlled environments to simulate real-life scenarios while observing the effects of specific variables on equine health. This page gathers peer-reviewed research articles and scholarly studies that explore the methodologies, findings, and implications of in vivo research in horses, contributing to the advancement of equine science and veterinary medicine.
Hamza E, Torsteinsdottir S, Eydal M, Frey CF, Mirkovitch J, Brcic M, Wagner B, Wilson AD, Jungi TW, Marti E.Insect bite hypersensitivity (IBH) is an IgE-mediated dermatitis of horses caused by bites of Culicoides spp. IBH does not occur in Iceland where Culicoides are absent. However, following importation into continental Europe where Culicoides are present, >or=50% of Icelandic horses (1st generation) develop IBH but
Mugnier S, Dell'Aquila ME, Pelaez J, Douet C, Ambruosi B, De Santis T, Lacalandra GM, Lebos C, Sizaret PY, Delaleu B, Monget P, Mermillod P....The mechanism of fertilization remains largely enigmatic in mammals. Most studies exploring the molecular mechanism underlying fertilization have been restricted to a single species, generally the mouse, without a comparative approach. However, the identification of divergences between species could allow us to highlight key components in the mechanism of fertilization. In the pig, in vitro fertilization (IVF) and polyspermy rates are high, and spermatozoa penetrate easily through the zona pellucida (ZP). In contrast, IVF rates are low in the horse, and polyspermy is scarce. Our objective was ...
Perkins JD, Bennett C, Windley Z, Schumacher J.To develop a reliable technique for sinoscopic examination of the ventral conchal (VCS) and rostral maxillary sinuses (RMS) of horses Methods: Descriptive study Methods: Cadaveric equine heads (n=40) Methods: The VCS and RMS were examined endoscopically using: (1) rostral trephination of the RMS (rostral RMS approach); (2) caudal trephination of the RMS (caudal RMS approach); (3) conchofrontal sinus (CFS) trephination followed by RMS trephination at a site identified by endoscopic transillumination of the maxillary bone at the most rostral aspect of the caudal maxillary sinus (CMS) (light-indi...
Larenza MP, Peterbauer C, Landoni MF, Levionnois OL, Schatzmann U, Spadavecchia C, Thormann W.To evaluate pharmacokinetics of ketamine and norketamine enantiomers after constant rate infusion (CRI) of a subanesthetic dose of racemic ketamine or S-ketamine in ponies. Methods: Five 6-year-old Shetland pony geldings that weighed between 101 and 152 kg. Methods: In a crossover study, each pony received a CRI of racemic ketamine (loading dose, 0.6 mg/kg; CRI, 0.02 mg/kg/min) and S-ketamine (loading dose, 0.3 mg/kg; CRI, 0.01 mg/kg/min), with a 1-month interval between treatments. Arterial blood samples were collected before and at 5, 15, 30, 45, and 60 minutes during drug administration and...
van Loon JP, Stienen PJ, Doornenbal A, Hellebrekers LJ.To determine whether epidurally derived evoked potentials (EPs) can be used to reliably assess nociception and antinociception in ponies. Methods: 7 ponies. Methods: EPs and electromyograms (EMGs) from the quadriceps femoris muscles were recorded simultaneously, following electrical stimulation applied to the distal portion of the hind limb. The effect of increasing stimulus intensity, conduction velocities of the stimulated nerves, effect of epidurally applied methadone, and effect of systemically administered propofol were evaluated. Results: In the EP and EMG waveforms, 2 distinct complexes...
Lindegaard C, Vaabengaard D, Christophersen MT, Ekstøm CT, Fjeldborg J.To compare effects of hot iron branding and microchip transponder injection regarding aversive behavioral reactions indicative of pain and inflammation in horses. Methods: 7 adult horses. Methods: In a randomized controlled clinical crossover study, behavioral reactions to hot iron branding and microchip transponder injection were scored by 4 observers. Local and systemic inflammation including allodynia were assessed and compared by use of physiologic and biochemical responses obtained repeatedly for the 168-hour study period. Serum cortisol concentration was measured repeatedly throughout th...
Bosch G, de Mos M, van Binsbergen R, van Schie HT, van de Lest CH, van Weeren PR.Extracorporeal shock wave therapy (ESWT) is frequently used in equine practice, but little is known about its biological action. Objective: To study the effects of ESWT on matrix structure and gene expression levels in normal, physiologically loaded tendinous structures in ponies. Methods: Six Shetland ponies, free of lameness and with ultrasonographically normal flexor and extensor tendons and suspensory ligaments (SL), were used. ESWT was applied at the origin of the suspensory ligament and the mid-metacarpal region of the superficial digital flexor tendon (SDFT) 6 weeks prior to sample taki...
Nagy A, Bodo G, Dyson SJ, Szabo F, Barr AR.Proximal diffusion of local anaesthetic solution after perineural anaesthesia may lead to the desensitisation of structures other than those intended. However, there is no evidence-based study demonstrating the potential distribution and diffusion of local anaesthetic solution after perineural analgesia in the distal limb. Objective: To document the potential diffusion of local anaesthetic solution using a radiopaque contrast model and to evaluate the influence of walking compared with confinement in a stable after injection. Methods: Radiopaque contrast medium was injected subcutaneously over...
Faleiros RR, Leise BB, Westerman T, Yin C, Nuovo GJ, Belknap JK.C-X-C motif ligand 1 (CXCL1) is an important chemokine of epithelial origin in rodents and humans. Objective: To assess in vivo and in vitro the regulation of CXCL1 in equine laminitis. Methods: Twenty adult horses. Methods: Real-time quantitative polymerase chain reaction (PCR) was used to assess expression of CXCL1 in samples of laminae, liver, skin, and lung from the black walnut extract (BWE) model of laminitis, and in cultured equine epithelial cells (EpCs). Tissue was obtained from control animals (CON, n = 5), and at 1.5 hours (early time point [ETP] group, n = 5), at the onset of leuko...
Schneberger D, Caldwell S, Suri SS, Singh B.Toll-like receptor 9 (TLR9) has been found to be the main receptor to respond to bacterial DNA in a wide variety of species. Recent work has shown that TLR9 is expressed in a diverse set of cells within the lung. However, much of this data has been centered on human and mouse cell culture lines or primary cultures and very little is known of TLR9 expression in intact lung, especially that of the horse. Here we show that TLR9 is expressed in the lungs of horses in a wide variety of cells. In particular, we note expression in pulmonary intravascular macrophages (PIMs), alveolar macrophages, bron...
Tyler CR, Filby AL, Bickley LK, Cumming RI, Gibson R, Labadie P, Katsu Y, Liney KE, Shears JA, Silva-Castro V, Urushitani H, Lange A, Winter MJ....Many factors have been considered in evaluations of the risk-benefit balance of hormone replacement therapy (HRT), used for treating menopausal symptoms in women, but not its potential risks for the environment We investigated the possible environmental health implications of conjugated equine estrogens (CEEs), the most common components of HRT, including their discharge into the environment, their uptake, potency, and ability to induce biological effects in wildlife. Influents and effluents from four U.K. sewage treatment works (STWs), and bile of effluent-exposed fish, were screened for six ...
Cribb NC, Bouré LP, Hanna WJ, Akens MK, Mattson SE, Monteith GJ, Weese JS.To assess the antimicrobial elution characteristics, toxicity, and antimicrobial activity of amikacin-impregnated ferric-hyaluronate implants (AI-FeHAI) for amikacin delivery to the tarsocrural joint of horses. Methods: Experimental study. Methods: AI-FeHAI implants, equine cartilage, and synovium, and horses (n=6). Methods: In vitro study: Five AI-FeHAI were placed in saline solution with daily replacement until implant degradation. Eluent was tested for amikacin concentration and bioactivity. Synovial and cartilage explants were incubated in the presence or absence of AI-FeHAI for 72 hours a...
Reardon R, Kummer M, Lischer C.To report a novel technique for cervical vertebral fusion in a foal with cervical vertebral malformation (CVM). Methods: Case report. Methods: A 3-month-old Warmblood filly with ataxia, weakness, and stenotic myelopathy at the level of the articulation of the 6th (C6) and 7th (C7) cervical vertebrae had a 7-hole broad locking compression plate (LCP) applied to the ventral aspect of C6 and C7 using seven 5.0-mm locking screws. Revision surgery was required to replace the self-drilling screws, which had migrated, with longer non self-drilling screws. Fusion and growth of the vertebrae were monit...
Leclere M, Lavoie JP, Dunn M, Bédard C.Thrombelastography (TEG) is used to evaluate the viscoelastic properties of blood during clotting and provides a global assessment of hemostasis and clot lysis. TEG analysis initiated with recombinant human tissue factor (TF) has not been evaluated in clinically healthy horses. Objective: The purpose of this study was to determine whether TEG results are affected by the time elapsed between sampling and analysis (storage time) of equine blood samples and to establish a preliminary equine reference interval for a modified TEG assay, using recombinant human TF to initiate coagulation. Methods: C...
Chiam R, Sharp E, Maan S, Rao S, Mertens P, Blacklaws B, Davis-Poynter N, Wood J, Castillo-Olivares J.African horse sickness virus (AHSV) causes a non-contagious, infectious disease in equids, with mortality rates that can exceed 90% in susceptible horse populations. AHSV vaccines play a crucial role in the control of the disease; however, there are concerns over the use of polyvalent live attenuated vaccines particularly in areas where AHSV is not endemic. Therefore, it is important to consider alternative approaches for AHSV vaccine development. We have carried out a pilot study to investigate the ability of recombinant modified vaccinia Ankara (MVA) vaccines expressing VP2, VP7 or NS3 genes...
Nourian AR, Mills PC, Pollitt CC.Intraosseous (i.o.) infusion of the distal phalanx (IOIDP) as a delivery route targeting hoof lamellar tissue of standing, conscious horses was evaluated. Following sedation and regional nerve blockade in six Standardbred horses, a microdialysis (MD) probe was implanted into the hoof lamellar tissue of one forelimb. A purpose designed cannulated bone screw was introduced into the body of the distal phalanx, approximately 6 cm from the MD probe. Gentamicin solution (25 mg/mL) was infused at 20 microL/min through the bone screw for 2 h without the application of a tourniquet. MD and blood sample...
Choi YH, Harding HD, Hartman DL, Obermiller AD, Kurosaka S, McLaughlin KJ, Hinrichs K.The reported patterns of trophectodermal expression of POU5F1 protein in blastocysts vary among species, and are possibly related to the differences in placental growth and function. This study investigated the pattern of embryonic POU5F1 expression in the horse, a species with delayed placental formation. Immature equine oocytes expressed POU5F1 protein in the cytoplasm and nucleus. Staining for POU5F1 protein in in vitro-produced (IVP) embryos decreased to day 5 of culture, then the nuclear staining increased to day 7. IVP day-7 to -11 blastocysts showed POU5F1 staining in nuclei throughout ...
Choi YH, Hartman DL, Fissore RA, Bedford-Guaus SJ, Hinrichs K.We evaluated the effect of different activation methods on blastocyst development after equine nuclear transfer. All activation treatments were followed by incubation in 2 mM 6-dimethylaminopurine for 4 h. In Experiment 1, reconstructed oocytes were injected with sperm extract for 0.1, 0.2, 0.4, 0.8, or 1.6 sec using a FemtoJet injection device, then treated with ionomycin. The blastocyst rate (9.8%) for 0.1-sec injection was significantly higher than that for 0.2 sec (0%) or 0.8 sec (1.4%). In Experiment 2, injection of murine PLCzeta cRNA before or after ionomycin treatment did not increase ...
Hanly BK, Stokes AM, Bell AM, Johnson JR, Keowen ML, Paulsen DB, Sod GA, Moore RM.To determine the feasibility of performing serial laminar and skin biopsies on sedated horses and whether sampling affected adjacent tissues. Methods: 6 horses. Methods: Laminar tissues were harvested via biopsy through the hoof wall from healthy conscious horses via sedation and regional anesthesia. Eight specimens were collected at 4 time points during 24 hours from a single foot. Laminar biopsy specimens were harvested with a 6-mm-diameter biopsy punch after burring through the horny corium to the stratum medium. Skin biopsy specimens were collected from an area proximal to the coronary ban...
Cheetham J, Pigott JH, Hermanson JW, Campoy L, Soderholm LV, Thorson LM, Ducharme NG.The equine upper airway is highly adapted to provide the extremely high oxygen demand associated with strenuous aerobic exercise in this species. The tongue musculature, innervated by the hypoglossal nerve, plays an important role in airway stability in humans who also have a highly adapted upper airway to allow speech. The role of the hypoglossal nerve in stabilizing the equine upper airway has not been established. Isolated tongues from eight mature horses were dissected to determine the distal anatomy and branching of the equine hypoglossal nerve. Using this information, a peripheral nerve ...
Ginther OJ, Siddiqui MA, Beg MA.The hypotheses were tested that prostaglandin F2alpha (PGF) travels from the uterus to the ovaries via a systemic route in mares, as opposed to a local route in ruminants, and that one pulse of PGF produces only partial luteolysis. Intravenous (i.v.) and intrauterine (i.u.) infusions of PGF were performed 8 days after ovulation at a constant rate for 2 h. Plasma concentrations of PGF were assessed by assay of 13,14-dihydro-15-keto-PGF2alpha (PGFM). Total doses administered were as follows: 0, 0.05, 0.1, 0.5 and 1.0 mg, i.v., PGF and 0 and 0.5 mg, i.u., PGF (n=4 mares per group). In addition, P...
De Santis T, Casavola V, Reshkin SJ, Guerra L, Ambruosi B, Fiandanese N, Dalbies-Tran R, Goudet G, Dell'Aquila ME.The extracellular calcium-sensing receptor (CASR) plays an important role in cells involved in calcium (Ca2+) homeostasis by directly sensing changes in the extracellular Ca2+ ion concentration. We previously reported the localization and quantitative expression of CASR protein in human oocytes. In this study, we examined the expression and the functional role of CASR during oocyte meiotic maturation in a large mammal animal model, the horse. As in humans, CASR protein was found to be expressed in equine oocytes and cumulus cells. Western-blot analysis revealed a single 130 kDa band in denuded...
Bonneau S, Maynard L, Tomczuk K, Kok D, Eun HM.In this blinded randomized and controlled study, the anthelmintic efficacy of a tablet formula of ivermectin-praziquantel was evaluated in horses experimentally infected with three species of Strongylus larvae. Eighteen previously dewormed horses were inoculated on study day 0 with third-stage larvae of Strongylus vulgaris, Strongylus equinus, and Strongylus edentatus. The horses were randomly allocated to three groups (n = 6): test-drug (tablet formula), positive-control (reference gel), and negative-control (placebo tablet). On day 56, the horses were treated once with the respective drugs. ...
Back W, MacAllister CG, van Heel MC, Pollmeier M, Hanson PD.Lameness is a highly prevalent condition in horses and the principal cause of removal from athletic activity. In clinical studies to evaluate nonsteroidal anti-inflammatory drug therapies, force plates are commonly used to assess improvement of lameness objectively. Objective: To use a force plate to determine the optimal dose of a new COX-2 inhibitor (firocoxib) that will reduce lameness, when administered orally to horses once daily. Methods: Sixty-four horses that exhibited chronic lameness presumed due to osteoarthritis, including navicular disease, in at least one of the frontlimbs and at...
Collins SN, Murray RC, Kneissl S, Stanek C, Hinterhofer C.The finite element (FE) method is the most powerful modelling technique available to explicate the biomechanics of the digit. It has already proved to be of high value in human podiatry. However, accurate models of the complex anatomy of the horse and donkey digit are currently lacking. Objective: To develop FE models of the horse and donkey digit from computed tomography data, including all functionally relevant anatomy, and to perform simulations to replicate prestrain in the flexor tendons and quasistatic weightbearing. Methods: Computed tomography data of the front right digits were obtain...
Davies HM.Data are required to confirm that strain gauges recording high bone strains in Thoroughbred racehorses provide an accurate record of bone strain. Objective: To test the accuracy and reliability of very high in vivo strain recordings made during fast exercise in Thoroughbred racehorses. Methods: Strains were recorded during exercise from rosette gauges implanted onto the mid-shaft dorsal cortex of each third metacarpal bone (MC3) in 6 yearling and 6 mature Thoroughbreds in a previous experiment. Bulk elastic modulus (E(US)) was calculated from ultrasound speed and single photon absorptiometry m...
Young NJ, Becker DL, Fleck RA, Goodship AE, Patterson-Kane JC.Energy-storing tendons including the equine superficial digital flexor tendon (SDFT) contribute to energetic efficiency of locomotion at high-speed gaits, but consequently operate close to their physiological strain limits. Significant evidence of exercise-induced microdamage has been found in the SDFT which appears not to exhibit functional adaptation; the degenerative changes have not been repaired by the tendon fibroblasts (tenocytes), and are proposed to accumulate and predispose the tendon to rupture during normal athletic activity. The anatomically opposing common digital extensor tendon...
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...
Ginther OJ, Siddiqui MA, Beg MA.Responses to intravenous treatment of mares with prostaglandin F2alpha (PGF) 8 d after ovulation were studied in three groups (n=4/group): control (no treatment), bolus (single treatment with 2.5 mg PGF), and infusion (0.1 mg PGF during 2 h). Infusion resulted in a 13,14-dihydro-15-keto-PGF2alpha (PGFM) concentration (559+/-44 pg/mL) that was not different from the mean concentration for the major portion of a natural PGFM pulse associated with luteolysis (569+/-45 pg/mL; n=5). Progesterone in the bolus group increased (P<0.03) between 0 (17.8+/-3.5 ng/mL) and 2 min (25.3+/-4.8 ng/mL), peak...
El-Kady EM, Ibrahim NM, Wahby AF.The horse antibodies to Naja haje (Nh) elicited in a low dose multi-site immunization protocol were investigated from binding perspective in the context of antivenom maturation. We found that, this protocol evoked the production of lethality neutralizing avid antibodies in the first round of immunization which increases over the successive immunization rounds. The changes and the relative changes in the antibody parameters of each horse were taken as a measure for the efficacy of its immune system to respond by gaining and magnifying the antivenom parameters. While the avidity increases over t...
Sharp DC, Grubaugh WR.Push-pull perfusion was used to study GnRH secretory ability of the hypothalamus in anoestrous, transitional, dioestrous and oestrous Pony mares. The technique involved placement of a concentric (tube within a tube) cannula into the area of the medial basal hypothalamus and perfusing a carrier medium (artificial cerebrospinal fluid) through the inner tube whilst aspirating from the outer tube so that the flow rate within the hypothalamic tissue was essentially constant. The perfusion rate was 0.5 ml/10 min and samples were collected at 10-min intervals for 10-15 h. The carrier medium, which co...
Collobert C, Bernard N, Lamidey C.The umbilical skin and ligamentum nuchae of 368 horses were examined post mortem for Onchocerca species. Only four of the horses were infected and pathological changes were observed on the skin of two of them. Thelazia lacrimalis was recovered from 38 (10.3 per cent) of the horses, and animals aged six months to two years were more frequently infected. No ocular lesions were observed. The prevalences of these two nematodes were low when compared with the infection rates reported in the United Kingdom and North America.
Freeman DE.Many surgical procedures of the head and neck can be safely performed in the standing horse, with easy access to all aspects of the surgical field. Some procedures, such as tracheotomy, are easier to perform with the horse standing with the head in a more natural position than with the horse under general anesthesia. Procedures of the neck and thorax that require evacuation of purulent and necrotic material from confined spaces, such as occur in horses with esophageal ruptures and extensive intrathoracic abscesses, can be done as standing procedures to avoid the risks of general anesthesia on ...
DiFranco B, Schumacher J, Morris D.Three horses were admitted for retrieval of polyurethane nasogastric tube fragments. The fragments were removed from the esophagus or stomach of 2 horses by manipulation of a snare introduced through the biopsy port of an endoscope. The fragments were surgically removed from the stomach of the third horse.
Bergan T, Versland I.To be active, antimicrobials must reach the bacteria in the infectious foci in adequate concentrations. Direct measurements of levels in the various foci are difficult to perform, but a number of animal models with artificial extravascular foci have been developed. In many ways, the physiology of pigs resemble that of humans. Consequently, it was thought that pigs might also parallel humans in the handling of penicillins. General pharmacokinetics of ampicillin and flucloxacillin and the penetration of the substances to subcutaneously implanted teflon tistisue chambers were investigated. Ampici...
Eurell TE, Wilson DA, Baker GJ.Serum haptoglobin concentration was used as an indicator of the acute phase response in ponies undergoing exploratory laparotomy. Preoperative, 1 h intraoperative, 3 h, 6 h, 12 h and 24 h postoperative blood samples and 48 h postoperative peritoneal fluid samples were obtained for haptoglobin analysis. A spectrophotometric assay based on cyanmethemoglobin binding capacity (CyanBC) was used to determine haptoglobin concentrations. The preoperative reference range for serum haptoglobin concentrations in these ponies was 25-60 mg CyanBC/dL. Intraoperative and 3 h postoperative blood samples had d...
Furr MO, Crisman MV, Robertson J, Barta O, Swecker WS.Immune system dysfunction and immunoglobulin deficiency was diagnosed in a 2-year-old horse with disseminated lymphosarcoma. Prolonged (35 days) parenteral nutrition was delivered to support the horse during a period in which immune function studies could be performed. Correction of nutritional compromise by use of parenteral nutrition did not correct the immunoglobulin deficiency, and results of lymphocyte phenotype testing did not indicate abnormal proportions of leukocytes. Lymphoblast transformation studies were suggestive of a circulating immunosuppressive factor in the horse's serum. Nor...
Li X, Morris LH, Allen WR.The effects of four reagents on the activation and subsequent fertilization of equine oocytes, and the development of these after intracytoplasmic sperm injection, were investigated. Cumulus-oocyte complexes collected from equine ovaries obtained from an abattoir were matured in vitro for 40-44 h in TCM199 medium before being injected, when in metaphase II, with an immobilized stallion spermatozoon. The cumulus-oocyte complexes were then subjected to one of five activation treatments: (a) 10 micromol ionomycin l(-1) for 10 min; (b) 7% (v/v) ethanol for 10 min; (c) 100 micromol thimerosal l(-1)...
Pascoe JR, Meagher DM, Wheat JD.Uterine torsion was diagnosed in 26 mares of various breeds. The mean duration of gestation was 9.6 months. The most common clinical history was intermittent unresponsive colic of varying duration. Diagnosis of uterine torsion was confirmed by rectal palpation, and surgical correction was achieved in most cases by standing flank laparotomy and manual repositioning of the gravid uterus. Recumbent laparotomy was used only if the mare was intractable, the uterus was ruptured, or hysterotomy was indicated. Of 20 foals determined to be alive during surgery, 14 (70%) were subsequently born alive.
Hodgson DR.This article reviews what are considered the basic concepts of gas transport, blood gases, and acid-base physiology is most mammalian species. Techniques for the appropriate collection of blood samples for blood gas and acid-base determinations in the newborn foal are described. Guidelines for interpretation of these values in the normal foal and those animals undergoing respiratory and metabolic derangements are provided.
Bielański W, Kaczmarski F.Semen samples were collected from 3 fertile stallions by means of an 'open' artificial vagina and examined under scanning and transmission electron microscopy. The stallion spermatozoon has many features in common with that of other mammals but differs specifically in that it has an asymmetric head, an abaxial position of the tail and an acrosome of small volume. The presence of microtubules in the neck is also a characteristic of stallion spermatozoa.
Scott EA, Snoy P, Prasse KW, Hoffman PE, Thrall DE.A yearling Quarter Horse colt was examined because of intermittent esophageal obstruction. A soft tissue mass was palpated in the cervical portion of the esophagus. Plain and contrast radiography and esophagoscopy were utilized to confirm the location of the lesion in the esophageal wall. Surgical exploration and removal of the mass was performed through a ventral midline cervical incision. Histologically, the mass was a keratinizing squamous epithelial inclusion cyst.
Saey V, Tang J, Ducatelle R, Croubels S, De Baere S, Schauvliege S, van Loon G, Chiers K.Friesian horses are known for their high inbreeding rate resulting in several genetic diseases such as hydrocephaly and dwarfism. This last decade, several studies focused on two other presumed hereditary traits in Friesian horses: megaoesophagus and aortic rupture. The pathogenesis of these diseases remains obscure but an important role of collagen has been hypothesized. The purpose of this study was to examine possible breed-related differences in collagen catabolism. Urinary specimens from Friesian (n = 17, median age 10 years old) and Warmblood horses (n = 17, median age 10 years...
Jatzlau A, Abdel-Ghaffar F, Gliem G, Mehlhorn H.Intense laboratory tests on experimentally infected mice and rats had shown that a mixture of micronized onions and coconut pulp decreases substantially (until disappearance) the worm load (trematodes, cestodes and nematodes) after oral uptake. As a consequence, feeding experiments of naturally infected sheep had been done in Egypt, in Saudi Arabia, and in Germany, which showed that treated animals grow up much better than untreated ones. The mean gain of body weight per animal was up to 6 kg within 4 weeks compared to untreated ones. These experiments were repeated again in the present study ...
Schneeweiss W, Stanek C, Wagner M, Hein I.The potential of five different commercial DNA isolation methods to remove real-time PCR inhibitors from the synovial fluid of horses, cattle and pigs was investigated. All kits with the exception of one included a silica column-based purification of the DNA. With the fifth kit, DNA purification is achieved by removing contaminating macromolecules by a desalting process. We used a recently developed method based on comparison of the real-time PCR signal of an artificial target incorporated into each PCR reaction in the presence of the isolated DNA from the sample, and in control samples contai...
McQueary CA, Worley DE, Catlin JE.Of 22 foals from 4 localities in southwestern Montana, 59% were found to be infected with Eimeria leuckarti. Oocysts collected from feces of 4 positive horses were sporulated and subsequently administered to a 5- to 6-month-old foal. The prepatent period was 31 days and the patent period was between 5 and 10 days.
Ibrahim M, Ferrer MS, Ellerbrock RE, Rollin E.The cytobrush is considered the method of choice to obtain endometrial samples. Rigid brush fibers, however, may induce endometrial irritation and bleeding, or cell fragmentation, decreasing quality and diagnostic value of the samples. It was hypothesized that samples collected using a novel cytotape would provide sample smears of greater quality and less blood contamination than the cytobrush. Endometrial samples were collected with a cytotape and a cytobrush from ten mares without endometritis. Endometritis was then induced with artificial insemination, and samples were again collected 6 h a...
Moore JN, White NA, Berg JN, Trim CM, Garner HE.Experimental small intestinal strangulation obstruction was produced in anesthetized ponies. The limulus amoebocyte lysate test demonstrated the presence of endotoxin in the general circulation 60 and 120 minutes following restoration of mesenteric blood flow. Mucosal degeneration, with loss of villus epithelial cells, was demonstrated coincident with endotoxemia. The findings were consistent with an ischemia-mediated alteration in the intestinal barrier to endotoxin.
Adams SB, Fessler JF, Rebar AH.Cytologic examination of serial peritoneal fluid samples of nine experimental ponies was performed during a 72 hour period following laparotomy. Six of the ponies had jejunal infarction induced by occlusion of the corresponding vasculature. Cytologic examination was also performed on the peritoneal fluid of a series of horses with naturally occurring abdominal crises presented to the Large Animal Clinic. A rapid staining technique allowed evaluation of smears within 5 minutes of obtaining the fluid. Alterations in peritoneal fluid of the experimental and clinical cases reflected an acute infla...
Serpa PBS, Brooks MB, Divers T, Ness S, Birschmann I, Papich MG, Stokol T.Horses with inflammatory and infectious disorders are often treated with injectable heparin anticoagulants to prevent thrombotic complications. In humans, a new class of direct oral acting anticoagulants (DOAC) appear as effective as heparin, while eliminating the need for daily injections. Our study in horses evaluated apixaban, a newly approved DOAC for human thromboprophylaxis targeting activated factor X (Xa). Our goals were to: (1) Determine pharmacokinetics and pharmacodynamics of apixaban after oral (PO) and intravenous (IV) administration in horses; (2) Detect any inhibitory effects of...
Sabnis SG, Gunson DE, Antonovych TT.Seven horses ranging from three to 15 years of age had nephrotic syndrome; at necropsy, renal tissue of all seven horses had the morphologic lesions of mesangioproliferative glomerulonephritis (membranoproliferative glomerulonephritis). Homogeneous eosinophilic material which filled the glomerular capillary lumina was found in five horses. Ultrastructurally, this material primarily consisted of electron-dense deposits with a fibrillar pattern in five horses and in one horse, rhomboid crystalline deposits which resembled deposits seen in human cryoglobulinemia. The association of mesangioprolif...
Etcharren V, Mouguelar H, Aguilar Valenciano JJ.Telocytes (TCs), a recently discovered special type of stromal cells, have been identified in many organs of many species, including the female and male reproductive system, with proposed multiple potential bio-functions such as homeostasis, immunomodulation, tissue remodeling and regeneration, embryogenesis, angiogenesis and even tumorigenesis. The aim of this study was to investigate the existence, and characteristics of telocytes in normal equine oviduct. To identify them, we used routine light microscopy, non-conventional light microscopy (NCLM), transmission electron microscopy (TEM), and...
Varner DD, Ward CR, Storey BT, Kenney RM.Equine spermatozoa were incubated in a chemically defined medium for 8 hours. The medium preserved spermatozoal viability, as assessed by total spermatozoal motility, progressive spermatozoal motility, and spermatozoal exclusion of eosin stain. Effects of time and divalent cation ionophore, A23187, on the occurrence and character of the spermatozoal acrosome reaction were determined. Two light microscopic assays, a triple-stain technique and a chlortetracycline fluorescence assay, were calibrated with transmission electron microscopy for detection of the acrosome reaction. Incubation time and ...
Leisinger CA, Medina V, Markle ML, Paccamonti DL, Pinto CRF.A novel in vivo model utilizing serial administrations of PGF2α to induce aluteal cycles in the mare was used to evaluate the effects of progesterone-deprivation on the morphology of in vivo preimplantation embryos. We hypothesized that equine embryos produced during induced aluteal cycles (AL) would be developmentally affected, characterized by earlier embryo stage at collection, smaller embryo diameter, and lower quality grade, compared with those collected on the same day post-ovulation from control cycles during diestrus (high progesterone; > 4 ng/mL). Seven cyclic mares with a median ...
Franklin SH, Price C, Burn JF.To develop the technique of respiratory sound analysis for the diagnosis of dorsal displacement of the equine soft palate. Objective: To show that 1) the displaced soft palate can spontaneously vibrate in the presence of expiratory airflow; 2) the observed frequency of vibration can be detected in respiratory sound recordings; and 3) the frequency of vibrations measured in cadaveric specimens are similar to those obtained from audio spectra in exercising horses with DDSP. Methods: Palatal movements and respiratory sounds were recorded from artificially ventilated cadaveric heads. The fundament...
Pearson W, Lindinger M.Nutraceuticals are increasingly applied to the management of equine arthritis and joint disease, particularly those based upon glucosamine and chondroitin sulphate. While the first report of using glucosamine in horses appeared more than 25 years ago, it was not until 1992 that isolated studies began to be reported. Since that time, 15 in vivo papers have been published in the equine literature, usually on products already commercially available and often seeking evidence for efficacy. These studies demonstrate an encouraging trend to manufacturers of these products investing in research, but ...
Herrera M, Herrera JM, Cantatore S, Aguilar J, Felipe A, Fumuso E.Uterine acute post-breeding inflammation is a physiological tissue response to the entry of exogenous elements, with persistent endometritis being the main pathology responsible for subfertility in the mare (Equus ferus caballus; Linnaeus, 1758). Mares can be classified as susceptible or resistant to endometritis according to their ability to remove intrauterine fluid within 48 hr after experimental inoculation. Endometrial biopsy is a technique that is commonly used to establish the degree of lesions that can affect the fertility of the mare. Endometrial histomorphometry is an objective and ...
Romagnoli N, Zannoni A, Bernardini C, Gobbetti T, Bombardi C, Rambaldi AM, Morini M, Dondi F, Rinnovati R, Lambertini C, Spadari A.Proteinase-activated receptor 2 (PAR) is a G-protein-coupled receptor for trypsin and mast cell tryptase; it is highly expressed at the intestinal level with multiple functions, such as epithelial permeability and intestinal motility. The aim of the study was to evaluate the distribution and expression of proteinase-activated receptor 2 in the small intestine during herniation through epiploic foramen. In this prospective clinical study, eight horses admitted for colic and which underwent exploratory laparotomy were considered. During surgery, the jejunum or the ileum was sampled by enterectom...
Kawcak CE, Trotter GW, Powers BE, Park RD, Turner AS.The purpose of this study was to compare bone healing induced by equine demineralized bone matrix (DBM) to autogenous cancellous bone graft (ACB) or no graft (control) in a rib-defect model in horses. Methods: The osteogenic properties of ACB and DBM were evaluated in bilateral 19-mm circular defects created in the outer cortex of the 6th and 8th ribs of each horse. Methods: Eight mature horses. Methods: Three rib defects in each horse were randomly treated with each of the 3 treatment groups, and the fourth rib defect received a random treatment. Rib sections, including the defects, were harv...
