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Topic:Animal Studies
Animal studies involving horses encompass a range of research focused on understanding equine biology, behavior, and health. These studies often investigate various aspects of horse physiology, genetics, nutrition, and disease pathology. Researchers utilize animal studies to explore the effects of different treatments, management practices, and environmental factors on horse welfare and performance. The findings from such studies contribute to the development of improved care strategies and health interventions. This page gathers peer-reviewed research studies and scholarly articles that explore the methodologies, findings, and implications of animal studies conducted on horses, providing insights into their application in advancing equine science.
Changes in collagen fibril network organization and proteoglycan distribution in equine articular cartilage during maturation and growth. The aim of this study was to record growth-related changes in collagen network organization and proteoglycan distribution in intermittently peak-loaded and continuously lower-level-loaded articular cartilage. Cartilage from the proximal phalangeal bone of the equine metacarpophalangeal joint at birth, at 5, 11 and 18 months, and at 6-10 years of age was collected from two sites. Site 1, at the joint margin, is unloaded at slow gaits but is subjected to high-intensity loading during athletic activity; site 2 is a continuously but less intensively loaded site in the centre of the joint. The degr...
Effects of platelet-rich plasma gel on skin healing in surgical wound in horses. To establish a low-cost method to prepare platelet-rich plasma (PRP) and evaluates the potential of platelet derived factors to enhance wound healing in the surgical wounds in equine. Methods: To obtain a PRP gel, calcium gluconate and autologous thrombin were added to platelet-rich plasma. For the tests six saddle horses were used and two surgical incisions were made in each animal. Wounds were treated with PRP gel or untreated. Sequential wound biopsies collected at Treatment 1: at days 5 and 30 and Treatment 2: at days 15 and 45 post wounding permitted comparison of differentiation markers ...
Transcutaneous ultrasonographic evaluation of the air-filled equine stomach and duodenum following gastroscopy. Gastroscopy with air insufflation was performed in 10 ponies, after which a transcutaneous ultrasound examination of the stomach and duodenum was performed immediately and at 1, 2, and 4 h postgastroscopy, and 24 h after feeding. Stomach measurements included the dorsoventral and craniocaudal dimensions, as well as the stomach depth from the skin surface and stomach wall thickness at the different time periods. Gastric wall folding was observed in one pony, becoming most distinct 2-4 h postgastroscopy. An undulating stomach wall was noted in eight other ponies postgastroscopy. These observatio...
A complementary radiographic projection of the equine temporomandibular joint. The complexity of the equine skull makes the temporomandibular joint a difficult area to evaluate radiographically. The goal of this study was to determine the optimal angle for a complementary radiographic projection of the equine temporomandibular joint based on a computed tomography (CT) cadaver study. CT was performed on six equine cadaver heads of horses that were euthanized for other reasons than temporomandibular joint disease. After the CT examination, 3D reconstruction of the equine skull was performed to subjectively determine the angle for a complementary radiographic projection of ...
Cholesterol addition protects membrane intactness during cryopreservation of stallion sperm. Addition of cholesterol to sperm membranes improved equine sperm stability during semen cryopreservation; however, it also reduced in vivo fertility. The objective of the present study was to determine the effects of adding cholesterol to stallion sperm prior to freezing, and subsequently removing it from frozen-thawed sperm. Semen from 12 stallions was subjected to four treatments: (T1) control, semen was diluted with Kenney extender, centrifuged, and resuspended to 100 x 10(6)spermatozoa/mL in INRA 82 freezing extender, packaged into 0.5-mL straws, cooled to 5 degrees C, and cryopreserved in...
Expressed gene sequences of the equine cytokines interleukin-17 and interleukin-23. This report describes the initial cloning and characterization of the equine interleukin-17 (IL-17) expressed gene sequence from mRNA obtained from equine intestinal tissue and interleukin-23 (IL-23) expressed gene sequence from mRNA obtained from equine peripheral blood mononuclear cells. Equine IL-17 has 462 nucleotides in the translated region, determined by homology with known human and mouse sequences, and shares 84% and 75% identity, respectively. For the deduced amino acid sequences, the identity with human and mouse is 76% and 70%. Equine IL-23 has 579 nucleotides in the translated reg...
Evidence for a novel vasospastic transmitter system, neuromedin U, in the equine digital circulation. The brain-gut peptide neuromedin U (NMU) is a ligand for the G-protein-coupled receptors, NMU1 and NMU2. In humans, an extended form of this peptide, NMU-25, and the structurally related peptide, neuromedin S (NMS), both produce potent vasoconstriction in isolated blood vessels. The aim of this study was to determine whether NMU fulfilled criteria for controlling vasoreactivity in the equine digital circulation. NMU receptors were characterised in the equine digital artery and vein based on the pharmacological criteria of specific, saturable and high affinity binding. Immunoreactive peptide wa...
Effect of transvenous electrical cardioversion on plasma cardiac troponin I concentrations in horses with atrial fibrillation. Whether electrical cardioversion of cardiac arrhythmias results in cardiomyocyte damage is unknown. Objective: To describe effect of transvenous electrical cardioversion (TVEC) on plasma cardiac troponin I (cTnI) concentration in horses. Methods: All horses presented to the Cornell University Hospital for Animals for cardioversion of atrial fibrillation between May 2006 and October 2008 were eligible for inclusion in the study. Owners of 14 horses elected for TVEC and each horse was then enrolled (16 procedures). Methods: Prospective observational study measuring concentrations of plasma cTnI ...
Social bonds between unrelated females increase reproductive success in feral horses. In many mammals, females form close social bonds with members of their group, usually between kin. Studies of social bonds and their fitness benefits have not been investigated outside primates, and are confounded by the relatedness between individuals in primate groups. Bonds may arise from kin selection and inclusive fitness rather than through direct benefits of association. However, female equids live in long-term social groups with unrelated members. We present 4 years of behavioral data, which demonstrate that social integration between unrelated females increases both foal birth rates a...
Influence of bone cements on bone-screw interfaces in the third metacarpal and third metatarsal bones of horses. To compare biomechanical strength, interface quality, and effects of bone healing in bone-implant interfaces that were untreated or treated with calcium phosphate cement (Ca-cement), magnesium phosphate cement (Mg-cement), or polymethylmethacrylate (PMMA) in horses. Methods: 6 adult horses. Methods: 4 screw holes were created (day 0) in each third metacarpal and third metatarsal bone of 6 horses. In each bone, a unicortical screw was placed in each hole following application of Ca-cement, Mg-cement, PMMA, or no treatment (24 screw holes/treatment). Screws were inserted to 2.82 N m torque. Hors...
Mixed inheritance of equine recurrent airway obstruction. Mode of inheritance of equine recurrent airway obstruction (RAO) is unknown. Objective: Major genes are responsible for RAO. Methods: Direct offspring of 2 RAO-affected Warmblood stallions (n = 197; n = 163) and a representative sample of Swiss Warmbloods (n = 401). Methods: One environmental and 4 genetic models (general, mixed inheritance, major gene, and polygene) were tested for Horse Owner Assessed Respiratory Signs Index (1-4, unaffected to severely affected) by segregation analyses of the 2 half-sib sire families, both combined and separately, using prevalences estimated in a representa...
Electrophysiological characterization of electrolyte and nutrient transport across the small intestine in horses. The aim of this study was to characterize the transport mechanisms of electrolytes and nutrients across the jejunum of nine healthy horses electrophysiologically. The stripped mucosa was mounted in Ussing chambers and tissue conductances (G(t)) and short circuit currents (I(sc)) were continuously monitored. After blocking the sodium and potassium channels with amiloride, tetraethylammonium chloride (TEA) and barium, chloride secretion was stimulated by carbachol and forskolin. Subsequently, chloride channels were inhibited by 4,4'-diisothiocyanato-stilbene-2,2'-disulfonic acid, 5-nitro-2-(3-ph...
Neurectomy of the deep branch of the lateral plantar nerve can cause neurogenic atrophy of the muscle fibres in the proximal part of the suspensory ligament (M. interosseous III). Neurectomy of the deep branch of the right lateral plantar nerve was performed on a single healthy mature horse. Six weeks after surgery, the horse was subjected to euthanasia and both hind suspensory ligaments harvested. The cross sectional area of the muscular part of the proximal part of the suspensory ligament was measured and assessed for morphological abnormalities in a blinded fashion. There was a clear difference in cross sectional area of the muscular part between treated and control ligament and there was profound neurogenic atrophy of the muscular fibres in the treated ligament.
The effect of rising and sitting trot on back movements and head-neck position of the horse. During trot, the rider can either rise from the saddle during every stride or remain seated. Rising trot is used frequently because it is widely assumed that it decreases the loading of the equine back. This has, however, not been demonstrated in an objective study. Objective: To determine the effects of rising and sitting trot on the movements of the horse. Objective: Sitting trot has more extending effect on the horse's back than rising trot and also results in a higher head and neck position. Methods: Twelve horses and one rider were used. Kinematic data were captured at trot during over gr...
Reproducibility of a non-invasive ultrasonic technique of tendon force measurement, determined in vitro in equine superficial digital flexor tendons. A non-invasive ultrasonic (US) technique of tendon force measurement has been recently developed. It is based on the relationship demonstrated between the speed of sound (SOS) in a tendon and the traction force applied to it. The objectives of the present study were to evaluate the variability of this non-linear relationship among 7 equine superficial digital flexor (SDF) tendons, and the reproducibility of SOS measurements in these tendons over successive loading cycles and tests. Seven SDF tendons were equipped with an US probe (1MHz), secured in contact with the skin overlying the tendon me...
Identification of chromosome abnormalities in the horse using a panel of chromosome-specific painting probes generated by microdissection. Fluorescent in situ hybridisation (FISH) using a panel of molecular probes for all chromosome pairs obtained by chromosome microdissection of the domestic horse ( Equus caballus ) was used to diagnose karyotype abnormalities in 35 horses (32 mares, 2 stallions and 1 intersex), which were selected for the study due to infertility (23 horses), reduced fertility (10 horses) and developmental anomalies (2 horses). The use of the FISH technique with probes for each horse chromosome pair enabled the diagnosis of many different chromosome aberrations in this population. Among the horses analysed, 21 ...
Intensity of activation and timing of deactivation modulate elastic energy storage and release in a pennate muscle and account for gait-specific initiation of limb protraction in the horse. The equine biceps brachii (biceps) initiates rapid limb protraction through a catapult mechanism. Elastic strain energy is slowly stored in an internal tendon and is then rapidly released to protract the forelimb. The muscle fibres are short, have little scope for length change and can therefore only shorten slowly compared with the speed at which the whole muscle must shorten, which makes them poor candidates for driving rapid limb protraction. We suggest that the muscle fibres in the biceps act to modulate the elastic energy output of the muscle-tendon unit (MTU) to meet the demands of locom...
A 40-year odyssey into the mysteries of equine luteolysis. Variation is the principal barrier to progress in unraveling the complexities of biological mechanisms. The resulting slow research progress is well illustrated in the chronology of events in elucidating the mechanism for regression of the corpus luteum (luteolysis) during the equine estrous cycle. Many of the underlying foundations of the female reproductive system in farm animals were developed during the 1930s to 1950s, despite the lack of methods for determining the concentrations of circulating hormones. In the 1960s, a uterine luteolysin was postulated on the basis of several experimenta...
Gas and particle concentrations in horse stables with individual boxes as a function of the bedding material and the mucking regimen. The aim of this study was to compare different types of bedding and mucking regimens used in horse stables on the generation of airborne particulate matter <10 microm (PM10) and 3 biogenic gases (carbon dioxide, nitrous oxide, and especially ammonia). Three separate experiments were undertaken. The experiments were carried out in an enclosed stable (9.7 m long, 8.7 m wide, and 3.5 m high) that had 5 single boxes housing 4 horses. The measuring instruments were set up in the middle of one side of the stable. In Exp. 1, 3 types of bedding material (wheat straw, straw pellets, and wood shavings) ...
Visual laterality in the domestic horse (Equus caballus) interacting with humans. Most horses have a side on which they are easier to handle and a direction they favour when working on a circle, and recent studies have suggested a correlation between emotion and visual laterality when horses observe inanimate objects. As such lateralisation could provide important clues regarding the horse's cognitive processes, we investigated whether horses also show laterality in association with people. We gave horses the choice of entering a chute to left or right, with and without the passive, non-interactive presence of a person unknown to them. The left eye was preferred for scannin...
[The occurrence of the hindgut ciliate Blepharocorys curvigula (Ciliophora: Blepharocorythidae) from horses (Equus caballus Linnaeus, 1758) in the vicinity of Izmir]. Blepharocorys curvigula Gassovsky, 1919 found in the intestine of domestic horses (Equus caballus Linnaeus, 1758), living in the vicinity of Izmir was investigated. It was seen in nine of the thirteen horses examined (69%). This study reports the presence of Blepharocorys curvigula in the intestine of Equids for the first time in Turkey. Specimens were found to be similar to the original descriptions on the basis of morphological characters and biometric data.
Increased IL-4 and decreased regulatory cytokine production following relocation of Icelandic horses from a high to low endoparasite environment. 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
New insights into the mechanisms of fertilization: comparison of the fertilization steps, composition, and structure of the zona pellucida between horses and pigs. 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 ...
The new framework for understanding placental mammal evolution. An unprecedented level of confidence has recently crystallized around a new hypothesis of how living placental mammals share a pattern of common descent. The major groups are afrotheres (e.g., aardvarks, elephants), xenarthrans (e.g., anteaters, sloths), laurasiatheres (e.g., horses, shrews), and euarchontoglires (e.g., humans, rodents). Compared with previous hypotheses this tree is remarkably stable; however, some uncertainty persists about the location of the placental root, and (for example) the position of bats within laurasiatheres, of sea cows and aardvarks within afrotheres, and of der...
A preliminary study of the effects of handling type on horses’ emotional reactivity and the human-horse relationship. Handling is a crucial component of the human-horse relationship. Here, we report data from an experiment conducted to assess and compare the effect of two training methods. Two groups of six Welsh mares were trained during four sessions of 50 min, one handled with traditional exercises (halter leading, grooming/brushing, lifting feet, lunging and pseudo-saddling (using only girth and saddle pad) and the second group with natural horsemanship exercises (desensitization, yielding to body pressure, lunging and free-lunging). Emotional reactivity (ER) and the human-horse relationship (HHR) were as...
Use of computed tomography in standing position to identify guidelines for screw insertion in the distal phalanx of horses: an ex vivo study. To compare the precision of radiography and computed tomography (CT) preoperatively in the standing position for identification of guidelines for screw insertion in the distal phalanx, and to identify whether standing CT might improve operative time compared with preoperative radiographic planning. Methods: Experimental ex vivo study. Methods: Cadaveric equine thoracic limb pairs (n=10). Methods: Insertion of a 4.5 mm cortex screw in lag fashion into an intact distal phalanx was evaluated in 2 groups (n=10) of cadaveric equine thoracic limbs. In 1 group, the site, direction, and length of the ...
Laparoscopic mesh incisional hernioplasty in five horses. To report a technique for incisional hernioplasty in horses using laparoscopic placement of a prosthetic mesh. Methods: Case series. Methods: Horses (n=5) with ventral median abdominal incisional hernia. Methods: A telescope and 2 instrument portals were established bilaterally, lateral to and distant from the hernia margins. After exposure of the internal rectus sheath by removal of retroperitoneal fat with endoscopic scissors and monopolar cautery, a prosthetic mesh was introduced into the abdomen and secured intraperitoneally using transfascial sutures with or without supplemental endoscopi...
Animal-related injuries: epidemiological and meteorological features. This is a retrospective and registry-based descriptive study including animal- related injuries represented by the most crowded Emergency Department (ED) in Eastern Turkey over a period of two years. Animal-related injuries were 0.2% of all ED admittances; dominant in males and were high in summer. 68% of the subjects were exposed to mammalians. Most prominent injuries were dog bites (30%), horse (22%) and livestock-related injuries (12%). Hospitalization was significantly higher in mammalian animal injuries compared to non-mammalian injuries. The highest hospitalization rate was measured for ...
Stereoselective pharmacokinetics of ketamine and norketamine after constant rate infusion of a subanesthetic dose of racemic ketamine or S-ketamine in Shetland ponies. 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...
