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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.
One percent sodium carboxymethylcellulose prevents experimentally induced abdominal adhesions in horses. To evaluate the efficacy of 1% sodium carboxymethylcellulose (SCMC) for prevention of experimentally induced abdominal adhesions in horses. Methods: Prospective, controlled, experimental study. Methods: Twelve healthy adult horses. Methods: The effect of 1% SCMC on adhesion formation was evaluated in 12 healthy horses by using an established model of serosal trauma to induce intraabdominal adhesions. After ventral median celiotomy, 2 separate areas of the jejunum were abraded, and three 2-0 chromic gut sutures were placed in each abraded area. Jejunal resection and end-to-end anastomosis was p...
Mapping of 31 horse genes in BACs by FISH. No abstract available
Disposition, elimination, and bioavailability of phenytoin and its major metabolite in horses. To determine pharmacokinetics and excretion of phenytoin in horses. Methods: 6 adult horses. Methods: Using a crossover design, phenytoin was administered (8.8 mg/kg of body weight, IV and PO) to 6 horses to determine bioavailability (F). Phenytoin also was administered orally twice daily for 5 days to those same 6 horses to determine steady-state concentrations and excretion patterns. Blood and urine samples were collected for analysis. Results: Mean (+/- SD) elimination half-life following a single IV or PO administration was 12.6+/-2.8 and 13.9+/-6.3 hours, respectively, and was 11.2+/-4.0 ...
Estimating transmission potential in gastrointestinal nematodes (order: Strongylida). Microparasite virulence (the potential to cause harm in the host) is thought to be regulated by a direct trade-off with pathogen transmission potential, but it is unclear whether similar trade-offs occur in macroparasites (helminths). In this analysis, the transmission potentials of 5 nematode species (order Strongylida), known to differ in their virulence, were estimated using an index based on egg production and larval survivability. Virulence estimates were based on the minimum number of worms that cause host death. In nematode species where mature adults cause pathology (trichonematidic de...
The anisotropic Young’s modulus of equine secondary osteones and interstitial bone determined by nanoindentation. The equine radius is a useful subject for examining the adaptation of bone histology to loading because in life the anterior cortex is loaded almost entirely in tension, the posterior cortex in compression. The histology of the two cortices is correspondingly different, the osteones and the interstitial lamellae in the posterior cortex having a more transversely oriented fibre arrangement than those in the anterior cortex. Presumably as a result of this histological difference, the posterior cortex is stronger in compression than the anterior cortex; the anterior cortex is stronger in tension ...
Myofibroblasts in the mucosal layer of the uterine tube. Uterine tubes from cow, sheep, horse, pig, dog, cat, rabbit, and guinea pig were examined immunohistochemically for presence and distribution of contractile cells in the mucosal lamina propria. We tested for the presence of alpha-smooth muscle actin, tropomyosin, desmin, smooth muscle myosin (heavy chain) and cytoskeletal proteins vimentin and cytokeratin. Immunostaining for alpha-smooth muscle actin showed two distribution patterns: either positive cells were freely dispersed in the mucosal lamina propria or a distinct subepithelial layer of positive cells was seen. The first distribution pat...
The human-horse relationship: how much do we know? Human relationships or interactions with horses have varied throughout history depending on human needs, but it is horses' ability to carry a human individual that has had perhaps the greatest impact on their relationship with man. Despite our long association with the horse, there have been few studies on human-horse relationships. There is little historical evidence on individual relationships with horses but indications of strong human-horse relationships have been noted in mounted societies, such as North American Plains Indians. Riding a horse has traditionally been associated with power,...
Understanding equine stereotypies. It is frequently asserted that equine stereotypies, such as crib-biting, wind-sucking and weaving, are caused by boredom. However, this explanation is too general to be of practical use in discerning the causes of each stereotypy or in devising management practices to prevent their occurrence. The majority of equine stereotypes start within one month of weaning when both the nutritional and social environment of the foal are substantially altered. Epidemiological research has revealed that the provision of low quantities of forage and minimal opportunities for social contact are associated wit...
Investigating the origins of horse domestication. Before the development of firearms, the horse was crucial to warfare and, before the invention of the steam engine, it was the fastest and most reliable form of land transport. It is crucial to the life of nomadic pastoralists on the Eurasian steppe and played a major role in the evolution of human society during the Bronze Age and Iron Age. Understanding the human past requires knowledge of the origins and development of horse husbandry. The problem of being able to identify the early stages of horse domestication is one that many researchers have grappled with for the most part unsuccessfull...
Horses and the rural economy in the United Kingdom. The horse industry is large and varied, but until comparatively recently its contribution to the economy of the UK has been virtually ignored and this, together with the disparate nature and small size of the individual businesses involved, has resulted in a general lack of universally available data. What is undoubtedly true, however, is that the horse touches upon the professional and recreational aspects of many peoples' lives and that, without the horse, not only would a significant proportion of the rural working population be unemployed but many ancillary industries would have considerab...
Magnetic resonance imaging of two normal equine brains and their associated structures. Magnetic resonance images were obtained from two isolated horses' heads. Ten mm thick, T1-weighted images were taken with a 1.5 Tesla magnet and a body coil, and compared with the corresponding frozen cross-sections of the heads, relevant structures being identified and labelled at each level. The images should provide reference material for clinical magnetic imaging studies of horses' heads.
Primary structure of kappa-casein isolated from mares’ milk. In this work the purification and the complete primary structure of kappa-casein from equine milk are reported for the first time. Mares' milk casein was separated by RP-HPLC into four fractions. Complete primary sequence was obtained by sequence analysis of the protein in the fastest eluting peak isolated by chromatography. This sequence was 95% identical to that reported for the C-terminal portion of the zebras' kappa-casein and showed high similarity with kappa-caseins from sources other than Equidae, confirming that this protein was indeed kappa-casein in equine milk. The presence of post-...
Tetranectin-like protein in vertebrate serum: a comparative immunochemical analysis. The glycoprotein tetranectin (TN) found in human serum is a 90-kDa homotrimeric C-type lectin binding Ca2+, heparin and plasminogen kringle 4. TN is suggested as being implicated in tissue remodelling. The antigenic reactivity of putative TN was examined in serum from 14 different animal species using three sandwich enzyme immunoassays for human TN. Crab-eating macaque serum showed the strongest reaction, followed by horse and cat. Serum from cow, goat, pig, mouse and chicken reacted weakly, while dog, trout, and the amphibian and the reptile species did not react. The TN-like protein from mac...
The metabolism of norethandrolone in the horse: characterization of 16-, 20- and 21-oxygenated metabolites by gas chromatography/mass spectrometry. After oral administration to a thoroughbred gelding, the anabolic steroid norethandrolone was converted into a complex mixture of oxygenated metabolites. These metabolites were extracted from the urine, deconjugated by methanolysis and converted to their O-methyloxime trimethylsilyl derivatives. Gas chromatographic/mass spectrometric analysis indicated the major metabolites to be 19-norpregnane-3,16,17-triols, 19-norpregnane-3,17,20-triols and 3,17-dihydroxy-19-norpregnan-21-oic acids. Some minor metabolites were also detected.
Oral treatment with a nutraceutical (Cosequin) for ameliorating signs of navicular syndrome in horses. Fourteen horses with a progressive forelimb lameness of 3 to 12 months' duration, diagnosed as navicular syndrome, were selected from clinical cases admitted to Auburn University Equine Hospital for evaluation of the efficacy of an orally administered nutraceutical (Cosequin, Nutramax Laboratories, Inc., Edgewood, MD) for ameliorating clinical signs associated with naturally occurring navicular syndrome. Horses were randomly allocated to treatment with the nutraceutical or a placebo. Treatment was five scoops (16.5 g) of powder twice daily in the feed. The test group (n = 8) received a patente...
In vitro evidence for effects of magnesium supplementation on quinolone-treated horse and dog chondrocytes. Quinolones and magnesium deficiency cause similar lesions in joint cartilage of young animals. Chondrocytes cultivated in the presence of quinolones and in Mg-free medium show severe alterations in cytoskeleton and decreased ability to adhere to the culture dish. We investigated whether Mg2+ supplementation can prevent quinolone-mediated effects on chondrocytes in vitro. Chondrocytes cultivated in Dulbecco's modified Eagle's medium/HAM's F-12 medium were treated with ciprofloxacin (80 and 160 microg/ml) and enrofloxacin (100 and 150 microg/ml). Mg2+ was added at a concentration of 0.0612 mg/ml...
Effect of contact stress in bones of the distal interphalangeal joint on microscopic changes in articular cartilage and ligaments. To examine articular cartilage of the distal interphalangeal (DIP) joint and distal sesamoidean impar ligament (DSIL) as well as the deep digital flexor tendon (DDFT) for adaptive responses to contact stress. Methods: Specimens from 21 horses. Methods: Pressure-sensitive film was inserted between articular surfaces of the DIP joint. The digit was subjected to a load. Finite element models (FEM) were developed from the data. The navicular bone, distal phalanx, and distal attachments of the DSIL and DDFT were examined histologically. Results: Analysis of pressure-sensitive film revealed signific...
Estimation of the probability for exceeding a threshold concentration of furosemide at various intervals after intravenous administration in horses. To estimate the probability for exceeding a threshold concentration of furosemide commonly used for regulatory purposes after IV administration of furosemide in horses. Methods: 12 mature healthy horses (6 Thoroughbreds and 6 Quarter Horses). Methods: Venous blood was collected from each horse prior to and 0.25, 0.5, 0.75, 1, 2, 3, 4, 4.5, 5, and 6 hours after administration of 250 or 500 mg of furosemide. Concentrations of furosemide were determined, using an ELISA. Concentration of furosemide was modeled as a function of time, accounting for inter- and intrahorse variabilities. On the basis ...
The effect of the NMDA receptor blocker, dextromethorphan, on cribbing in horses. Stereotypic cribbing in horses is thought to involve excess dopaminergic activity within the striatum. Various models of stress-induced stereotypies including cribbing in horses postulate that stress stimulates the release of endorphins, triggering the release of striatal dopamine. Dopamine in turn activates basal ganglia motor programs, reinforcing behavior via a reward mechanism. Furthermore, the release of dopamine by endorphins has been shown to depend on activation of NMDA receptors. In the present study, horses identified as cribbers and volunteered by their owners were treated with the ...
The effect of bilateral palmar digital nerve analgesia on the compressive force experienced by the navicular bone in horses with navicular disease. Horses with navicular disease have an increased load on the navicular bone in early stance. This has been suggested to be a response to pain in the heel region. Seven horses with clinical, radiographic and scintigraphic signs of navicular disease underwent forceplate and kinematic analysis before and after desensitisation of the heel region with a bilateral palmar digital nerve block. The compressive force exerted on the navicular bone during stance, and stride kinematics, were determined in each state. After regional analgesia of the palmar digital nerves (PDNB) the compressive force on the n...
The force and contact stress on the navicular bone during trot locomotion in sound horses and horses with navicular disease. Mechanical overload due to poor conformation or shoeing has been suggested to contribute to the development of navicular disease. While studies have determined the compressive force exerted on the navicular bone in normal horses, this has not been reported for horses with navicular disease. Also, the force has not been converted to stress by correction for contact area. In this study we developed a technique for the determination of the contact area between the deep digital flexor tendon and the navicular bone in vivo, and used a forceplate system to determine the force and stress on the bone ...
Effect of load on preferred speed and cost of transport. Horses have a tendency to utilize a relatively narrow set of speeds near the middle of a much broader range they are capable of using within a particular gait, i.e., a preferred speed. Possible explanations for this behavior include minimizing musculoskeletal stresses and maximizing metabolic economy. If metabolic economy (cost of transport, CT) and preferred speeds are linked, then shifts in CT should produce shifts in preferred speed. To test this hypothesis, preferred speed was measured in trotting horses (n = 7) unloaded on the level and loaded with 19% of their body weight on the level. T...
Isolation of virulent Rhodococcus equi from native Japanese horses. R. equi was isolated from soil samples obtained from the environment of seven native Japanese horse breeds (Hokkaido, Kiso, Noma, Misaki, Tokara, Miyako and Yonaguni) and from fecal samples collected from three native horse breeds (Hokkaido, Kiso and Misaki). Virulent R. equi at various levels (ranging from 0.5 to 12.9%) was isolated from the feces or soil environment of Hokkaido, Kiso and Misaki horses. Isolates were investigated both for the presence of 15- to 17-kDa antigens (virulence-associated protein antigens; VapA) by colony blotting, using the monoclonal antibody 10G5, and the gene of...
Glycerol hyperhydration in resting horses. To determine whether administration of glycerol-containing solutions induces a state of transient hyperhydration in resting euhydrated horses, changes in plasma and urine constituents were measured in four horses for 1 h before and 5 h after nasogastric administration of each of four treatments (Experiment 1). Treatments were applied in a randomized fashion and included: (1) 1.0 g.kg(-)(1)glycerol in 8 L of water (G); (2) 8 L of water (W); (3) 8 L of 0.9% NaCl solution (S); and (4) 1.0 g.kg(-)(1)glycerol in 8 L of 0.9% NaCl solution (GS). In a subsequent study, voluntary water intake was measu...
Scanning electron microscopic study of the posterior ciliary veins in domestic ungulates. Vascular corrosion casts of 12 equine, 15 bovine and 50 porcine eyes were studied scanning electron microscopically for the presence of posterior ciliary veins. These veins drain a postequatorial segment of the choroid and emerge near the posterior bulbar pole. They complement the four vorticose veins that emerge near or at the equatorial zone of the eyeball and the slender choroidoretinal veins that drain the peridiscal area of the choroid. Posterior ciliary veins were observed in all equine and bovine eyes examined. In these species they presented a large variation in size, number and positi...
Effects of a histamine type 2 receptor antagonist, BMY-26539-01, on equine gastric acid secretion. A dose-response study was undertaken of the effects of a newly developed histamine type 2 receptor antagonist, BMY-26539-01, on gastric acid secretion in 4 fasted horses. Doses of 0.1 mg/kg, 0.3 mg/kg, 0.5 mg/kg, or placebo were administered in a randomly assigned treatment sequence. Hydrogen ion concentration and pH were variable during baseline measurements in all 4 animals; however, following BMY-26539-01 administration, mean pH increased and hydrogen ion concentration decreased in a dose-related pattern. At the 0.3 mg/kg and 0.5 mg/kg dose levels, pH remained elevated for > 4 h and >...
