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.
ADAMS KM.The ciliate population of the large intestine of the horse shows large, daily variations. The ventral colon is the site where the ciliate fauna varies most. Two species, Cycloposthium edentatum and C. dentiferum, became established in the large intestine after passage through the stomach and small intestine. The introduction of new species into the ventral colon caused significant changes in the fauna of that part of the gut.
ALLFREY V, MIRSKY AE.It has been found that many animal tissues contain "acid" desoxyribonucleases with pH optima near 5.2. A chemical method for the determination of this activity is described. The pancreatic desoxyribonuclease crystallized by Kunitz and shown to have a neutral pH optimum occurs in the pancreas together with the "acid" enzyme, but only the "neutral" enzyme occurs in the pancreatic juice. The ratio of "neutral" to "acid" DNAase activities in the pancreas is greater than 200, but in all other tissues examined there is no appreciable concentration of the neutral enzyme. It is concluded that neutral ...
Helal IE, Al-Abbadi HA, El-Daharawy MH, Ahmed MF.Delayed healing associated with distal limb wounds is highly challenging in equine clinical practice. This study aimed to evaluate healing rates between chronic non-granulating wounds of horse distal limbs that were treated with maltodextrin/ascorbic acid gel alone or in combination with povidone-iodine 1% solution and those treated with povidone-iodine 1% only throughout the study period (35 days) in clinical settings. The study was conducted on 18 adult horses (3-15 years old). Based on the treatment regimen utilized, the horses were divided into three groups (n = 6), with each group having ...
Delatour P, Benoit E, Bourdin M, Gobron M, Moysan F.After the administration of racemic ketoprofen and carprofen to man, both enantiomers of each compound exhibit similar plasma profiles. This contrasts with the rat where the active S(+) enantiomer is predominant. For carprofen, regardless of the route of administration, the R(-) enantiomer is predominant in the plasma of all investigated animal species. The S(+)/R(-) ratio of the "areas under the curves" during the time course of the kinetics, is: 0.60 in dogs, 0.53 in Yucatan micro-pigs, 0.48 in mini-goats, 0.67 in calves and 0.19 in horses. For ketoprofen, the S(+) enantiomer is predominant ...
McConnico RS, Weinstock D, Poston ME, Roberts MC.To determine whether quantification of myeloperoxidase (MPO) activity could be a useful laboratory technique to detect granulocyte infiltration in equine intestinal tissues. Methods: Intestinal tissue (inflamed or healthy) collected from 16 age- and sex-matched Shetland Ponies. Methods: Intestinal tissue MPO activity was determined, and histologic assessment of adjacent specimens from healthy and inflamed intestine was done. Results: Intestinal tissue MPO activity and histopathologic score increased with time after castor oil challenge and peaked at 16 hours in an equine diarrhea model in whic...
Fortin-Trahan R, Lemirre T, Santschi EM, Janes JG, Richard H, Fogarty U, Beauchamp G, Girard CA, Laverty S.There is a knowledge gap about how equine MFC subchondral radiolucencies (SR) arise and evolve. Osteoclasts are believed to have a role but have not been studied in situ. Objective: To measure and compare osteoclast density and the percentage of chondroclasts in healthy and MFC SR specimens from juvenile Thoroughbreds. Methods: Cadaveric study. Methods: Medial femoral condyles (MFC) from a tissue bank of equine stifles were studied. Inclusion criteria were MFCs (≤8 months old) with a computed tomography SR lesion and histological focal failure of endochondral ossification (L group). Contral...
Berardinelli P, Barazzoni AM, Russo V, Brunetti O, Della Torre G, Scapolo PA, Muttini A, Bortolami R.Based on previous observations that capsaicin can selectively damage group III and IV afferents and induce muscle fibre transformation, we hypothesized that eliminating, by means of capsaicin, the group III and IV afferents of a peripheral territory it could lead to a fibre transformation in a muscle involved in the flexor reflexes of the same peripheral territory. Therefore, capsaicin was injected into the palmar nerves of the forelimb of the horse to investigate if eliminating group III and IV afferents from the hand of the horse a muscle fibre transition would occur in the flexor carpi radi...
Jha S, Hall JA, Cherian G, Henry LR, Schlipf JW.Neutrophils are involved in inflammation through leukotriene (LT) production. The predominant proinflammatory leukotriene released from neutrophils is LTB4, which serves as a biological marker of inflammation. The purpose of this study was to optimize the conditions ex vivo for LTB4 production by neutrophils from horses and dogs, and platelets from chickens. Optimal production of LTB4 was characterized by incubation time (2.5, 5, 10, 15 or 20 min), temperature (25 or 37 degrees C), and calcium ionophore A23187 concentration (0.1, 1, 10 or 20 microM). Incubation longer than 2.5 min did not incr...
Major MD, Grant BD, White KK, Ratzlaff MH, Gallina AM, Donati RM.The suspensory apparatus of one forelimb was surgically disrupted in six adult horses by transecting the distal sesamoidean ligaments. A double-braided prosthetic ligament made of aramid yarn was installed to support the flexor surface of the metacarpophalangeal joint. The prosthesis was routed through tunnels in the third metacarpal bone and proximal phalanx, and secured to bone with screws. Evaluation by radiography, synovial fluid analysis, cinematography, and dynamography was performed before surgery and at weeks 16 and 30. Supracondylar cortical lysis and periosteal proliferation were obs...
Reilly PT, van Eps A, Stefanovski D, Pfau T.Horseshoes with modified contact surfaces combined with deformable ground substrates are used to change hoof orientation during mid-stance, for example, for therapeutic reasons. Objective: To measure the effect of horseshoes and ground substrates on sagittal and transverse plane hoof orientation at mid-stance using a dorsal hoof wall mounted triaxial accelerometer. Methods: In vivo experiment, randomised crossover design. Methods: Differences in sagittal and transverse plane angles between standing and mid-stance of the left front hoof of six horses walking with regular horseshoes, egg bar, to...
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...
Tanaka Y, Suganuma K, Watanabe K, Kobayashi Y.Dourine, caused by infection with Trypanosoma equiperdum, is one of the trypanosomiasis in equids. The clinical course of dourine is long-term, ranging from 1-2 months to several years. Since the pathogenesis of dourine has not yet been elucidated, experimental studies using mouse infection models are needed. Although mice are not susceptible to most T. equiperdum strains, some strains can infect mice. Even in such strains, infected mice develop rapidly transient parasitemia and die within 2-8 days. Therefore, mice experimentally infected with these T. equiperdum strains are not suitable for m...
Smith EJ, Beaumont RE, McClellan A, Sze C, Palomino Lago E, Hazelgrove L, Dudhia J, Smith RKW, Guest DJ.Tendon injuries occur commonly in both human and equine athletes, and poor tendon regeneration leads to functionally deficient scar tissue and an increased frequency of re-injury. Despite evidence suggesting inadequate resolution of inflammation leads to fibrotic healing, our understanding of the inflammatory pathways implicated in tendinopathy remains poorly understood, meaning successful targeted treatments are lacking. Here, we demonstrate IL-1β, TNFα and IFN-γ work synergistically to induce greater detrimental consequences for equine tenocytes than when used individually. This includes ...
Jackman BR, Moore JN, Barton MH, Morris DD.The purpose of this study was to investigate the in vitro effects of flunixin meglumine, a cyclo-oxygenase inhibitor, and ketoprofen, a reported cyclo-oxygenase and lipoxygenase inhibitor, on the synthesis of cyclo-oxygenase end-products thromboxane B2 and prostaglandin E2, lipoxygenase derived 12-hydroxyeicosatetraenoic acid, tumor necrosis factor and tissue factor. Six adult horses were each randomly administered flunixin meglumine (1.1 mg/kg) or ketoprofen (2.2 mg/kg) intravenously every 12 hours with the drug treatments separated by two weeks. Blood samples were obtained prior to initiatin...
Mills EP, Liu CC, Emelogu U, Carter RT, Camacho-Luna P, Lewin AC.The purpose of this study was to validate the use of the Reichert Tono-Vera® Vet tonometer rabbit setting in normal ex vivo rabbit eyes and to compare the rabbit setting to the dog, cat, and horse settings of this tonometer. Methods: Six freshly enucleated normal rabbit eyes were cannulated and connected to a fluid reservoir and physiologic monitor. Triplicate measurements were obtained with the four available settings: dog, cat, horse, and rabbit at various intraocular pressures (IOP) ranging from 5 to 80 mmHg. Bland-Altman analysis was utilized to determine bias and 95% limits of agreemen...
Marquardt J, Heymer J, Heinz H, Adolf GR, Deegen E.Recombinant equine interferon-beta 1 (reqIFN-beta 1) induces an antiviral state in blood mononuclear cells (BMC) of horses. Maximal protection against replication of vesicular stomatitis virus is achieved 6 hours after treatment with IFN in vitro and in vivo. Duration of the protective effect depends on the dose of IFN in vitro and in vivo. Availability of reqIFN-beta 1 in cultures of BMC for up to 48 hours does not prolong the antiviral state. The protective effect on BMC after treatment with IFN has similar duration in vivo and in vitro. Monitoring of the effect of IFN in vivo is, thus, simp...
Muñoz JA, Marcoux M, Picandet V, Theoret CL, Perron MF, Lepage OM.Palatal sclerotherapy using sodium tetradecyl sulfate has been suggested as a treatment for dorsal displacement of the soft palate in young Standardbred horses. The present study evaluated histological and biomechanical changes in the equine soft palate following trans-endoscopic treatment with a low dose of this compound. Two horses were euthanased and examined at 2 weeks and at 1, 2, 4 and 6 months post-sclerotherapy, while two further horses served as untreated controls. The technique was easily performed in all cases without major complications. On histological examination there was no evi...
Madsen K, Martens A, Haspeslagh M, Meulyzer M, Gustafsson K.Medical grade honey (MGH) has been introduced as a protective measure against surgical site infections in equine surgery, but the effect on suture material has not been investigated. Objective: To evaluate the effect of MGH on the tensile properties of three synthetic absorbable suture materials. Methods: In vitro experiments. Methods: Ten strands of Polydioxanone USP 2 (PD2), Polyglactin 910 USP 2 (PG2) and Polyglecaprone USP 2-0 (PC2-0) were incubated 1, 7, 14, 21 and 28 days in MGH, phosphate-buffered saline (PBS), equine plasma (EP) and MGH mixed with equine plasma (HP). Mechanical testi...
Bellitto NA, Oliver FB, Pollock PJ.To evaluate the use of bidirectional knotless barbed suture material for closure of the equine linea alba. Methods: Laboratory study. Methods: Adult light horse cadavers (n = 24). Methods: A 25 cm incision was made through the linea alba, and a 200 L polyurethane bladder was positioned within the abdomen. The linea alba was closed either using USP2/EP5 bidirectional polydioxanone barbed suture or USP2/EP5 standard polydioxanone suture in a simple continuous pattern. Closure time was recorded for each suture type. The bladder was air-insufflated at 40 L/min, and the pressure at body w...
Chavatte-Palmer P, Duchamp G, Palmer E, Ousey JC, Rossdale PD, Lombès M.Progesterone, oestrogen and glucocorticoid receptor concentrations in the uterus and mammary glands of pregnant mares during mid- to late gestation (from day 150 of gestation to term) were measured by binding assays to investigate the hormonal mechanisms involved in pregnancy maintenance and lactation. Uterine progesterone receptor concentrations did not increase significantly with increasing gestational age (from 67.8 +/- 13.7 to 126.1 +/- 48.7fmol mg(-1) protein), whereas oestrogen receptor concentrations were significantly higher in pregnant mares (271.7 +/- 28.9 fmol mg(-1) protein) than i...
Borges LM, Ferreira LA, da Silva LS, de Oliveira RA, Mussi SV, Faria KA, Melo LS, Abud LJ, Costa GL, Soares SF.This study was carried out with the objective of evaluating the efficacy of a 2,6-dichlorophenol (2,6-DCP) lure to control Dermacentor nitens (Acari: Ixodidae). Slow-release formulations of the pheromone formulated with and without cypermethrin were prepared. Olfactometer bioassays were used to define the best dose of the pheromone and to evaluate the effect of cypermethrin with 2,6-DCP attractiveness. Sexually active males were released 15 cm from 2 cmx1 cm pieces of polypropylene treated with different odors: 2,6-DCP in a liposphere system (1.5, 30 and 300 microg--without cypermethrin and 30...
Armstrong S, Tricklebank P, Lake A, Frean S, Lees P.Carprofen is a Non Steroidal Anti-Inflammatory Drug (NSAID) which is widely used for the treatment of musculoskeletal disorders in horses. The commercial preparation is a racemic mixture of two enantiomers (R and S carprofen). We used HPLC to measure plasma and synovial fluid R and S carprofen concentrations following a single intravenous (i.v.) dose, and computer modelling to determine the pharmacokinetic parameters of the enantiomers in these two body fluids. A comparison was made with results from an identical experiment using ketoprofen. The plasma elimination half lives of R and S carprof...
Rabinovsky ED, Yang TJ.A tumor antigen (TA) associated with murine leukemia-lymphoma L5178Y cells has been identified by the enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IIF) techniques. The antigen was present in both non-solubilized and 0.5% NP-40 solubilized membrane extracts. Rabbit anti-L5178Y lymphoma serum (RALS), extensively absorbed with normal mouse tissues, identified TA in extracts of L5178Y lymphoma and L5178Y leukemia cells grown in horse serum (L5178Y/HS), but not in extracts of L5178Y cells grown in fetal calf serum (L5178Y/FCS). Similarly, absorbed rabbit anti-L5178Y/HS...
van de Lest CH, van den Hoogen BM, van Weeren PR, Brouwers JF, van Golde LM, Barneveld A.Osteochondrosis (OC) is a disturbance in the process of endochondral ossification, a process in which cartilage is mineralised and transformed into bone. In this process different biochemical events occur, of which the cartilage component has been studied so far almost exclusively. In this study we concentrated on the biochemical characterisation of normal and osteochondrotic subchondral bone, by analysis of enzyme activities, DNA content and phospholipids (PL). In subchondral bone, lysyl oxidase and both total and bone alkaline phosphatase activity were significantly increased in all degrees ...
Maclellan LJ, Albertini DF, Stokes JE, Carnevale EM.The impact of vitrification on oocyte developmental competence as a function of donor age remains an important issue in assisted reproductive technologies (ARTs). Methods: Equine germinal vesicle (GV) or metaphase II (M(II) oocytes were vitrified using the Cryotop® method. Spindle organization and chromosome alignment were evaluated from confocal imaging data sets of in vivo (IVO) or in vitro (IVM) matured oocytes subjected to vitrification or not. Intracytoplasmic sperm injection (ICSI) from the same groups was used to assess developmental potential. Results: An increase in chromosome misali...
Frabasile L, Amendola C, Buttafava M, Chincarini M, Contini D, Cozzi B, De Zani D, Guerri G, Lacerenza M, Minero M, Petrizzi L, Qiu L, Rabbogliatti V....Biosensors applied in veterinary medicine serve as a noninvasive method to determine the health status of animals and, indirectly, their level of welfare. Near infrared spectroscopy (NIRS) has been suggested as a technology with this application. This study presents preliminary time domain NIRS measurements of optical properties (absorption coefficient, reduced scattering coefficient, and differential pathlength factor) and hemodynamic parameters (concentration of oxygenated hemoglobin, deoxygenated hemoglobin, total hemoglobin, and tissue oxygen saturation) of tissue domestic animals, specif...
Barnabé MA, Elliott J, Harris PA, Menzies-Gow NJ.Hypoadiponectinaemia is a risk factor for endocrinopathic laminitis, but the directionality and nature of its association with insulin dysregulation is unclear. Objective: To investigate the effects of short-term induced hyperinsulinaemia and dexamethasone challenge on circulating [total adiponectin] and whole blood expression of adiponectin (AdipoR1 and AdipoR2), insulin, and insulin-like growth factor 1 (IGF-1) receptors in insulin-sensitive ponies. Methods: In vivo experiment. Methods: Six never-laminitic, insulin-sensitive, native-breed UK ponies first underwent a dexamethasone challenge (...
Fitzgerald DM, Cash CM, Dudley KJ, Sibthorpe PEM, Sillence MN, de Laat MA.Active glucagon-like peptide-1 (aGLP-1) has been implicated in the pathogenesis of equine insulin dysregulation (ID), but its role is unclear. Cleavage of proglucagon (coded by the GCG gene) produces aGLP-1 in enteral L cells. Objective: The aim in vivo was to examine the sequence of the exons of GCG in horses with and without ID, where aGLP-1 was higher in the group with ID. The aims in vitro were to identify and quantify the expression of GCG in the equine intestine (as a marker of L cells) and determine intestinal secretion of aGLP-1. Methods: Genomic studies were case-control studies. Expr...
Barnabé MA, Elliott J, Harris PA, Menzies-Gow NJ.The hormones insulin and adiponectin are commonly measured in equids because of their involvement in endocrinopathic laminitis. These are currently measured in serum/plasma, although jugular venipuncture can cause stress in some animals and may be impossible in needle-shy individuals. However, both hormones can be measured in saliva in other species. Objective: To determine whether [insulin] and [total adiponectin] are detectable in equine saliva using automated assays and whether saliva collection is associated with changes in stress indicators. Additionally, the correlation between serum and...
De Coster T, Van Poucke M, Bogado Pascottini O, Angel-Velez D, Van den Branden E, Peere S, Papas M, Gerits I, Govaere J, Peelman L, Vermeesch JR....In addition to fulfilling many breeders' curiosity, equine embryonic sex determination can have a profound commercial impact. However, the application of currently described assays for equine embryonic sexing has rendered variable diagnosis and validation rates, with sensitivity being the main problem. In addition, while pregnancy results of in vivo-flushed equine embryos following a needle aspiration biopsy equal those of non-biopsied embryos, the effect on in vitro-produced embryos is unknown. Here, we aimed to develop a highly sensitive and specific assay for equine sex determination that c...
Osterrieder K, Dorman DC, Burgess BA, Goehring LS, Gross P, Neinast C, Pusterla N, Hussey GS, Lunn DP.Equine herpes virus type 1 (EHV-1) infection in horses is associated with respiratory and neurologic disease, abortion, and neonatal death. Objective: Vaccines decrease the occurrence of clinical disease in EHV-1-infected horses. Methods: A systematic review was performed searching multiple databases to identify relevant studies. Selection criteria were original peer-reviewed research reports that investigated the in vivo use of vaccines for the prevention of disease caused by EHV-1 in domesticated horses. Main outcomes of interest included pyrexia, abortion, neurologic disease, viremia, and n...
Webster A, Pezzanite L, Hendrickson D, Griffenhagen G.Equine practitioners frequently inject local anaesthetics (LA) intra-articularly in both diagnosis of lameness and for pain management intra- or post-operatively with synovial endoscopy. Recent reviews of the human and veterinary literature support the concept that chondrotoxicity of LA on joint tissues depends on the type of drug, dose administered, and duration of exposure. The purpose of this review is to summarise the current literature describing intra-articular local anaesthetic use, including both in vitro and in vivo studies, and to draw some comparisons to literature from other specie...
