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.
Anderson RS, Day NK, Good RA.Natural hemagglutinin activity against vertebrate erythrocytes is present in the hemolymph of the cockroach Blabarus craniifer. The hemagglutinin titer against rabbit erythrocytes is high, whereas sheep and horse red cells agglutinate weakly. Hemagglutinin activity was depressed by the complement inhibitor, cobra venom factor. Cockroach hemagglutinin is heat-labile; all activity is destroyed by heating at 56 C for 1 hr. A humoral factor similar to the complement component 3 proactivator is also present in cockroach hemolymph. The formation of the cobra venom factor-hemolymph "complex" is depen...
Cabasso VJ, Nieman R, Schroeder DD, Hok KA, Louie RE, Mozen MM.A horse has been immunized with Australia antigen (Au/SH) purified 20-fold by a procedure employing gel filtration of Cohn fraction IV derived from an Au/SH-positive human plasma pool. Hyperimmunization was initiated by the intramuscular injection of 20 ml of a mixture of equal parts of purified Au/SH and complete Freund's adjuvant. The 20-ml volume was divided into four 5-ml doses, two of which were administered on each side of the horse's neck. Booster doses of antigen alone were given as follows: 10 ml intravenously 30 days later and 5 ml intramuscularly on each of days 77 and 205. Au/SH an...
Gruber J.Purified and concentrated Venezuelan equine encephalitis (VEE) virus derived from tissue cultures, rendered noninfectious by ionizing radiation with retention of in vitro serological activity, also retained a high level of immunogenicity. In mice, fluid vaccines afforded excellent protection against lethal challenge with homologous Trinidad strain VEE virus. A direct relationship was observed between concentration of vaccine or number of injections and survival. One intraperitoneal inoculation of undiluted vaccine protected essentially all mice challenged 21 days later with 100,000 mouse intra...
Marois P, Boudreault A, DiFranco E, Pavilanis V.Rhesus monkeys and ferrets were exposed to intranasal inoculation of several strains of egg-adapted avian, equine and human influenza viruses and to strains of mouse-adapted equine influenza viruses. Local replication of virus and seroconversion were observed in the majority of these animals. However, clinical infection was observed only in ferrets.
Stromberg BR, Norberg AW.Forty-six horses were submitted to a thermographic screening test. Forty showed a reasonably uniform IR-emission pattern of the coronary corium of the forelegs. The 133Xe-disappearance rate was studied in six of these horses, and the wash-out curves were found to be almost similar between the two extremities of each horse, except for slight differences between individual horses. Six horses showed a different IR pattern. Three had both coronary bands, and three had one coronary band, showing lower temperature. All cases with less warm coronary bands showed a low 133Xe-disappearance rate at rest...
Hill DW, Hyde WG, Kind AJ, Greulich D, Hopkins S.Aramine (metaraminol bitartrate) has been found in the possession of horse trainers and veterinarians who have been investigated for possible inappropriate drug administration to racing horses. Metaraminol (3-hydroxyphenylisopropanolamine) is a sympathomimetic amine that directly and indirectly affects adrenergic receptors, with alpha effects being predominant. Because it has the potential to affect the performance of a racing horse, its use is prohibited. In the present study, methods for the detection of metaraminol were developed. Metaraminol was found to be extracted with poor recovery ( 9...
Donald PJ, Deckard-Janatpour K, Sharkey N, Lagunas-Solar M.Various centers report irradiated cartilage graft absorption rates that differ quite widely. We postulated that a major factor governing this phenomenon might be irradiation dose. Irradiation produces collagen cross-binding and increased resistance to absorption of such material when implanted. Since cross-binding produces stiffening of collagen, cartilage grafts were exposed to increasing doses of irradiation and their elastic modulus was measured. The postulate was that increasing radiation doses will produce grafts of increasing stiffness. Sternal cartilage, harvested from horses, was cut i...
Noble P, Collin B, Lecomte-Beckers J, Magnée A, Denoix JM, Serteyn D.This study describes an equine joint friction test using a cartilage-on-cartilage arrangement and investigates the influence of age and load on the frictional response. Osteochondral plugs were extracted from equine shoulder joints (2-5 years, n=12; 10-14 years, n=15), and mounted in a pin-on-disc tribometer. The frictional response was then measured under constant conditions (2N; 20 degrees C; 5 mm/s), and with increasing load (2N, 5N, 10N). In all experiments, the friction coefficient of young cartilage was significantly (P<0.001) smaller than obtained from old cartilage, while the applicati...
Farrall H, Handscombe MC.More work is necessary to establish corneal dimensions and retinal structure and neural organisation in the equine eye. This paper reports a case of surgical management of bilateral cataracts in a pony and the results of a survey of refractive error in normal horses. Aspects of accommodation are discussed. It is suggested that a difference in retinal receptor organisation between horse and human eyes could explain the good visual performance of the aphakic pony; and that the degree of blurring of vision in the aphakic situation is less, both in absolute terms and in proportion to presumed norm...
Willmann C, Budik S, Walter I, Aurich C.A positive influence of altrenogest treatment on a retarded development of the conceptus around the beginning of placentation in mares older than 8 years could be recently demonstrated. In the present study, effects of altrenogest treatment in early-pregnant mares on conceptus development and expression of endometrial and embryonic genes were investigated. Genes were chosen according to a possible involvement in embryo-maternal interaction and embryonic development in the equine species. Mares were treated with altrenogest (0.044 mg/kg bodyweight) or sunflower oil (placebo) from day 5 to 11 af...
Wang Y, Chen Y, Wei Y.Clinical therapeutics for the regeneration of osteochondral defects (OCD) in the early stages of osteoarthritis remain an enormous challenge in orthopaedics. For in-depth studies of tissue engineering and regenerative medicine in terms of OCD treatment, the utility of an optimal OCD animal model is crucial for assessing the effects of implanted biomaterials on the repair of damaged osteochondral tissues. Currently, the most frequently used in vivo animal models for OCD regeneration include mice, rats, rabbits, dogs, pigs, goats, sheep, horses and nonhuman primates. However, there is no single ...
Wang X, Kole AR, Greenwald GS.This study was designed to determine whether the major site of eCG neutralization by an antiserum to the hormone is at the peripheral or ovarian level. Hamsters hypophysectomized at oestrus were injected s.c. with 25 iu eCG. Three days later, preovulatory follicles were dissected and cultured for 5 h and the medium was changed every hour. At the end of the first hour of incubation, oestradiol and androstenedione accumulation was high, with a sharp drop over the next 4 h, whereas progesterone concentrations did not change over the entire period. Addition of eCG antiserum to the incubated follic...
Brommer H, Rijkenhuizen AB, Brama PA, Barneveld A, van Weeren PR.There are many noninvasive diagnostic methods used for evaluating chronic progressive joint disease, but each has severe limitations in the detection of early articular cartilage damage. Objective: To evaluate the accuracy of arthroscopy as a diagnostic method for the assessment of the severity of cartilage surface damage on the proximal articular margin of the equine first phalanx (P1). Objective: That arthroscopic assessment of the visible cartilage provides 1) a good indication of the integrity of the cartilage surface and 2) a good estimation of the status of the cartilage surface of the e...
Drudge JH, Lyons ET, Tolliver SC, Kubis JE.The efficacy of oxibendazole given at dose level of 10 mg/kg of body weight was determined by 10 critical tests in foals and by 2 clinical trials in 20 foals (16 treated, 4 nontreated), with special interest in the drug activity against Parascaris equorum. The drug was uniformly efficacious (100%) against P equorum in the 10 critical-test foals, each having between 22 and 236 ascarids. Posttreatment reductions of ascarid egg counts in fecal samples were also 100% in suckling foals treated with oxibendazole given as a drench. Ascarid eggs did not reappear in fecal samples until the 8th week aft...
Park HB, Marklund S, Jeon JT, Mickelson JR, Valberg SJ, Sandberg K, Andersson L.The PRKAG3 gene encodes a muscle-specific isoform of the regulatory gamma subunit of AMP-activated protein kinase (AMPK). A major part of the coding PRKAG3 sequence was isolated from horse muscle cDNA using reverse-transcriptase (RT)-PCR analysis. Horse-specific primers were used to amplify genomic fragments containing 12 exons. Comparative sequence analysis of horse, pig, mouse, human, Fugu, and zebrafish was performed to establish the exon/intron organization of horse PRKAG3 and to study the homology among different isoforms of AMPK gamma genes in vertebrates. The results showed conclusively...
Talboom JS, Engler-Chiurazzi EB, Whiteaker P, Simard AR, Lukas R, Acosta JI, Prokai L, Bimonte-Nelson HA.In women, ovarian hormone loss at menopause has been related to cognitive decline, and some studies suggest that estrogen-containing hormone therapy (HT) can mitigate these effects. Recently, the Women's Health Initiative study found that conjugated equine estrogens, the most commonly prescribed HT, do not benefit cognition. Isolated components of conjugated equine estrogens (tradename Premarin(®)) have been evaluated in vitro, with delta(8,9)-dehydroestrone (∆(8)E1) and equilin showing the strongest neuroprotective profiles. It has not been evaluated whether ∆(8)E1 or equilin impact cogn...
Godbout M, Vargas A, Hélie P, Bullone M, Lavoie JP.To use a biopolymer delivery system to investigate the ability of interleukin (IL)-4 to recruit neutrophils into subcutaneous tissues of equids. Methods: 16 horses and 2 ponies. Methods: Animals were assigned to 3 experiments (6/experiment). Effects of recombinant equine (Req) IL-4 (100, 250, or 500 ng/site) versus a positive control (ReqIL-8; 100 ng, 250 ng, or 1 μg/site) and a negative control (Dulbecco PBSS or culture medium) on neutrophil chemotaxis were assessed after SC injection into the neck with an injectable biopolymer used as the vehicle. Tissue samples including the biopolymer plu...
Pelli AC, Winter K, Offhaus J, Brehm W, Gerlach K.In equine skeletal scintigraphy, there is no information about the possible influence of different phosphonate compounds on image quality. This prospective randomised study determined bone uptake changes and image quality for hydroxymethylene diphosphonate (HDP) and methylene diphosphonate (MDP) in equine patients at different time points. Scintigraphic images of the radius and the tibia of 20 horses were acquired at 2 and 4 hours after injection of either technetium-labelled HDP or MDP. Three regions of interest were identified-in the bone diaphysis, adjacent soft tissue and background area-t...
Neuwirth L, Romine C.The construction of ancillary equipment used to improve image quality and reduce personnel radiation exposure in the equine nuclear medicine laboratory is illustrated. The devices include a self supporting lead sheet for shielding the distal limb or limb pair, a hanging lead sheet for shielding the proximal limb, a lead square for shielding the urinary bladder or jugular catheter, a restraining board for acquiring a palmar view of the foot, a head support to stabilize the head for imaging and a head support for stabilizing the neck for imaging. The restraining board and head supports decrease ...
Holyoak GR, Little TV, McCollam WH, Timoney PJ.The relationship between stage of reproductive tract maturity and susceptibility to the experimental establishment of persistent infection with equine arteritis virus (EAV) was investigated in 21 prepubertal and 15 peripubertal colts. Five of six prepubertal colts inoculated intranasally remained infected in the reproductive tract from post-challenge day 28 to 93 and two of six from post-challenge day 120 to 180. No virus was detected in five of these animals killed on post-challenge day 210. Each of two peripubertal colts remained infected in the reproductive tract at post-challenge day 60 an...
Guelfi JF, Kraouchi DE.Chemotaxis and superoxide anion production of neutrophils in healthy horses were investigated before and 8 h after, a single injection of dexamethasone at a dose of 0.045 mg/kg. Chemotaxis was studied by the technique of migration under agarose and superoxyde production was measured by ferricytochrome c reduction. Superoxide anion production was not changed, but the chemotactic index, with zymosan activated horse serum, was increased. The FMLP chemoattractant effect, at 10(-4) M, was slightly enhanced.
Moreno-Martinez F, Byrne D, Raisis A, Waldmann AD, Hosgood G, Mosing M.Equine respiratory physiology might be influenced by the presence of an endotracheal tube (ETT). This experimental, randomized cross-over study aimed to compare breathing pattern (BrP) and ventilation distribution in anesthetized horses spontaneously breathing room air via ETT or facemask (MASK). Six healthy adult horses were anesthetized with total intravenous anesthesia (TIVA; xylazine, ketamine, guaiphenesin), breathing spontaneously in right lateral recumbency, and randomly assigned to ETT or MASK for 30 min, followed by the other treatment for an additional 30 min. During a second anesthe...
Löfgren M, Ekman S, Svala E, Lindahl A, Ley C, Skiöldebrand E.Formation of synovial joints includes phenotypic changes of the chondrocytes and the organisation of their extracellular matrix is regulated by different factors and signalling pathways. Increased knowledge of the normal processes involved in joint development may be used to identify similar regulatory mechanisms during pathological conditions in the joint. Samples of the distal radius were collected from prenatal and postnatal equine growth plates, zones of Ranvier and articular cartilage with the aim of identifying Notch signalling components and cells with stem cell-like characteristics and...
Cokelaere SM, Groen WMGAC, Plomp SGM, de Grauw JC, van Midwoud PM, Weinans HH, van de Lest CHA, Tryfonidou MA, van Weeren PR, Korthagen NM.There is an increasing interest in controlled release systems for local therapy in the treatment of human and equine joint diseases, aiming for optimal intra-articular concentrations with no systemic side effects. In this study, the intra-articular tolerability and suitability for local and sustained release of tacrolimus (FK506) from monospheres composed of [PDLA-PEG1000]-b-PLLA multiblock copolymers were investigated. Unloaded and tacrolimus-loaded (18.4 mg tacrolimus/joint) monospheres were injected into the joints of six healthy horses, with saline and hyaluronic acid (HA) in the contralat...
Adams SB, Lamar CH, Masty J.Bipolar stainless steel electrodes were surgically implanted in 4 ponies to record myoelectrical and mechanical activity of the distal portion of the jejunum and pelvic flexure. After determining normal activity, the effects of neostigmine, xylazine, flunixin meglumine, dipyrone, panthenol, and atropine sulfate were determined. Flunixin meglumine, dipyrone, and panthenol had no effect on the motility of the jejunum or pelvic flexure. Xylazine and atropine sulfate decreased motility of the distal portion of the jejunum and pelvic flexure, with atropine sulfate having a greater effect and lastin...
Bosch G, van Schie HT, de Groot MW, Cadby JA, van de Lest CH, Barneveld A, van Weeren PR.Tendon injuries are notorious for their slow and functionally inferior healing. Intratendinous application of platelet-rich plasma (PRP) has been reported to stimulate the repair process of tendon injuries, but there is little conclusive evidence for its effectiveness. A placebo-controlled experimental trial was performed to test the hypothesis that a single intratendinous PRP treatment enhances the quality of tendon repair, as evidenced by improved biochemical, biomechanical, and histological tissue properties. In six horses, tendon lesions were created surgically in the Superficial Digital F...
The Journal of heredityAugust 4, 2021
Volume 112, Issue 5 443-446 doi: 10.1093/jhered/esab037
Hammons V, Ribeiro L, Munyard K, Sadeghi R, Miller D, Antczak D, Brooks SA.Chestnut coat color in horses is determined by a missense mutation within the MC1R gene. However, the intensity of the chestnut color can vary widely within individuals possessing this genotype. Here, we investigated this variation using standardized photographs of 96 horses. Each horse was ranked lightest to darkest within the cohort for phenotype by 3 blinded observers. A genome-wide association study utilizing the relative shade ranking as the phenotype and using 268 487 single-nucleotide polymorphisms (SNPs) genotyped using the Affymetrix Equine 670k array identified a single significantly...
Harman RM, Churchill KA, Jager MC, Van de Walle GR.Equid herpesvirus 1 (EHV-1) outbreaks occur when virus spreads from infected horses to in-contact horses, primarily via nasal shedding. This study evaluated the efficacy of factors secreted by equine peripheral blood derived mesenchymal stromal cells (PB-MSCs), collectively named the secretome, to inhibit the growth of EHV-1 in (i) 2D epithelial cell cultures (RK-13) in vitro, (ii) 3D equine nasal explants in vitro and (iii) an EHV-1 infection mouse model in vivo. The PB-MSC secretome was found to inhibit EHV-1 in RK-13 cells as well as in the epithelium of equine nasal explants. Although the ...
Johannessen MK, Skretting G, Ytrehus B, Røed KH.Endochondral bone formation is an important process in development and growth of the skeleton; still many of the mechanisms of growth cartilage remain unknown. The aim of this study was to identify genes specifically expressed in growth cartilage by constructing a subtraction cDNA library of the articular-epiphyseal cartilage complex from neonatal foal. Two hundred and eighty-four differently expressed clones, representing five novel and 37 known genes, were detected by subtraction hybridization. The tissue specificity of these genes was verified by reverse Northern analysis, and tissue distri...
Kleine LG, Solano M, Rusckowski M, Hunt KE, Johnson KL, Kirker-Head CA.To evaluate the use of technetium Tc 99m-labeled EDTA-biotin monomer ((99m)Tc-EB1) as a scintigraphic imaging agent for soft tissue inflammatory lesions in horses. Methods: 6 healthy adult horses. Methods: First (phase 1), the agent's safety and blood-tissue clearance and an appropriate imaging protocol were determined in 6 horses. Each horse was injected with (99m)Tc-EB1 (1.1 GBq, IV, once); images were acquired at intervals during the following 24-hour period. Subsequently (phase 2), inflammation was induced via injection of 200 mg (10 mL) of mepivacaine (0.4 mg/kg) into the right neck muscu...
Matsumoto T, Okumura S, Hirata S.This study aimed to apply radar technology to a large quadruped animal. We first developed a non-contact respiration measurement system using millimeter-wave array radar for a horse in standing position. Specifically, we measured the respiration of a stationary domestic horse in stables. Simultaneously, we measured the respiration rate using infrared thermography and developed a method for analyzing the radar information while verifying the rate of agreement. Our results suggested that the radar technology detected breathing and accurately measured the respiration of a horse, despite variation...
De Geest JP, Lauwers H, Simoens P, De Schaepdrijver L.The present investigation of 20 equine eyes shows that the iridocorneal angle of the horse is characterised by a very distinct pectinate ligament and a large ciliary cleft. The pectinate ligament consists of long and broad pigmented trabeculae which form a firm, flat and dense network that encircles the eye. On meridional sections, the ciliary cleft is visible as a wide triangular space comprising the trabecular meshwork which consists of two parts. The inner part is the larger and forms a three-dimensional network of large pigmented trabeculae with very wide intertrabecular spaces. The outer ...
Klohnen A, Vachon AM, Fischer AT.To evaluate the use of abdominal ultrasonography as a diagnostic tool in horses with signs of colic. Methods: Prospective study. Methods: 226 horses with signs of acute abdominal pain were compared to 20 clinical normal horses. Methods: The following were performed in horses with signs of colic: physical examination, CBC, abdominal fluid analysis, placement of a nasogastric tube to obtain gastric reflux, abdominal palpation per rectum, and ultrasonography of the abdomen. Results of ultrasonography were compared with the surgical, necropsy, or medical findings. Results: Ultrasonography of horse...
Onasanya AE, El-Hage C, Diaz-Méndez A, Vaz PK, Legione AR, Browning GF, Devlin JM, Hartley CA.Equid gammaherpesvirus 2 (EHV2) is a gammaherpesvirus with a widespread distribution in horse populations globally. Although its pathogenic significance can be unclear in most cases of infection, EHV2 infection can cause upper respiratory tract disease in foals. Co-infection of different strains of EHV2 in an individual horse is common. Small regions of the EHV2 genome have shown considerable genetic heterogeneity. This could suggest genomic recombination between different strains of EHV2, similar to the extensive recombination networks that have been demonstrated for some alphaherpesviruses. ...
Smith ML, Chapman CB.An acepromazine (ACP) hapten was synthesised, coupled to bovine serum albumin and injected into a horse to produce antibodies to the drug. A competitive ELISA was developed whereby ACP attached to the solid phase via lysozyme competed with free ACP present in phosphate buffered saline, horse serum or horse urine for limiting amounts of antibody. The assay could detect the presence of ACP and, or, some of its metabolites in horse urine for at least 25 hours after intravenous injection of 0.1 mg kg-1 ACP maleate, but because of non-specific interference, horse serum could not be used. As little ...
