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Topic:Equine Studies
Equine Studies encompasses the scientific exploration and analysis of various aspects related to horses, including their physiology, behavior, genetics, nutrition, and management. This interdisciplinary field integrates knowledge from veterinary medicine, animal science, and equine management to enhance understanding of horse health and welfare. Topics within equine studies often include the study of equine anatomy, disease prevention, breeding practices, and performance optimization. Researchers and scholars contribute to this field by conducting experiments, field studies, and reviews that provide insights into improving equine care and management practices. This page compiles peer-reviewed research studies and scholarly articles that investigate diverse areas within equine studies, offering comprehensive insights into the complexities of horse biology and management.
The function of the equine carpal joint: a review. The most consistent published ideas on the function of the carpal joint of the horse concern the elasticity of the joint, and its limits to extension. Most of these are not well substantiated experimentally. Compression stress appears to be absorbed by the intercarpal ligaments as the carpal bones are separated by a wedge action during loading. Overextension is prevented by occlusion of dorsally located stop facets on the rows of carpal bones, and by the support of a stay apparatus.
The macroscopic vascular anatomy of the equine ethmoidal area. The vascular anatomy of the ethmoidal area in six normal horses and two normal ponies was studied using vascular-corrosion casts. The major arterial supply to the ethmoidal area stems from an intracranial source. The internal and external ethmoidal arteries anastomose on the rostral intracranial surface of the cribriform plate to form the arterial ethmoidal rete which arborizes and passes through the perforations of the cribriform plate to supply the ethmoid labyrinth. A minor arterial supply to the ventral portion of the ethmoid labyrinth stems from a small caudal nasal branch of the sphenopa...
Management factors associated with stereotypic and redirected behaviour in the thoroughbred horse. A greater knowledge of the effect of management factors is required to investigate the ontogeny of abnormal behaviour in the stabled horse. A postal survey of racehorse (flat) trainers yielded information about 22 yard and management factors. The relationship of the factors to the prevalence of abnormal behaviour was analysed by logistic regression. Management factors related to the time spent in the stable showed the strongest associations with stereotypic behaviour. The risk of horses performing abnormal behaviour increased: 1) as the amount of forage fell below 6.8 kg/day, 2) when bedding t...
Immunohistochemical localisation of steroidogenic enzymes and phenylethanolamine-N-methyl-transferase (PNMT) in the adrenal gland of the fetal and newborn foal. An increase in fetal adrenal cortisol output signals the onset of parturition in many animal species but, in the fetal horse, plasma concentrations of cortisol remain low for much of late pregnancy, with a rise occurring only very close to the time of birth (term 320-360 days). Immunohistochemistry was used to determine the localisation and changes in distribution of key steroidogenic enzymes for cortisol production; P450scc, P450C17 and 3 beta-hydroxysteroid dehydrogenase (3 beta HSD) in adrenal tissue from fetal and newborn horses and these findings were correlated with the appearance of imm...
Influence of stochastic events on the phenotypic variation of common white leg markings in the Arabian horse: implications for various genetic disorders in humans. One method of assessing the influence of stochastic events on phenotypic variation is to study morphological differences in paired limbs of the same individual. These limbs have identical genotypes and similar intra-uterine environments and are analogous to monozygotic twins. Common white leg markings have a multifactorial mode of inheritance in the Arabian horse. Asymmetry occurs frequently for these markings. Using computerized registration records obtained from the Arabian Horse Registry of America, Inc., the types of markings were quantified in the left foreleg and left hind leg of bay and...
The effect of training on equine metacarpal bone breaking strength. Right third metacarpal bones (n = 24) from Thoroughbreds, 24 to 48 months old and in race training, were tested to failure in 3 point bending. The neutral load axis was estimated and the distance from the axis to the outer dorsal cortical surface measured. Mid-diaphyseal dorsopalmar and lateromedial outer cortical and medullary diameters were measured. Breaking strength, cortical area and area moment of inertia were also calculated. Significant correlations were demonstrated between months in training and dorsopalmar bone diameter, cortical area and area moment of inertia. Significant linear m...
Diaphyseal structural properties of equine long bones. We evaluated the single-cycle structural properties for axial compression, torsion, and 4-point bending with a central load applied to the caudal or lateral surface of a diaphyseal segment from the normal adult equine humerus, radius, third metacarpal bone, femur, tibia, and third metatarsal bone. Stiffness values were determined from load-deformation curves for each bone and test mode. Compressive stiffness ranged from a low of 2,690 N/mm for the humerus to a high of 5,670 N/mm for the femur. Torsional stiffness ranged from 558 N.m/rad for the third metacarpal bone to 2,080 N.m/rad for the fe...
Ontogeny and ultradian rhythms of adrenocorticotropin and cortisol in the late-gestation fetal horse. Fetal maturation and the timing of parturition in both sheep and primates are thought to be controlled by the hypothalamic-pituitary-adrenal axis but little is known about the endocrinology of the equine fetus. We investigated the ontogeny of plasma concentrations of adrenocorticotropic hormone (ACTH), cortisol and corticosteroid binding capacity in the late-gestation fetal horse. We also wished to determine whether there is ultradian rhythmic release of ACTH and cortisol in fetal horses and we compared fetuses to maternal and non-pregnant adult horses. Six fetuses, 278-304 days gestation (ter...
He-Ne laser therapy by fibroendoscopy in the mucosa of the equine upper airway. A study was made of the effects of low-level laser irradiation on the cicatrization of superficial wounds in the pharyngeal mucosa of the horse. Methods: Duplicate pharyngeal mucosal ulcers were induced in 12 Spanish horses with submucosal injection of sulfuric acid. A fibroendoscope and an He-Ne laser were used to treat one of the ulcers and the second ulcer in each animal was left untreated, serving as a control. Biopsy samples for the histological study were taken after the seventh laser therapy session from the two animals. Results: Irradiated lesions cicatrized at 10.5 days and nonirradia...
Stimulation of KCl co-transport in equine erythrocytes by hydrostatic pressure: effects of kinase/phosphatase inhibition. The effects of hydrostatic pressure on the KCl co-transporter of equine erythrocytes were studied to determine factors involved in its regulation. Pressure (0.1-40MPa) increased Cl-dependent K+ transport; in the presence of the putative kinase inhibitor N-ethylmaleimide (NEM) which stimulates the transporter, or the phosphatase inhibitor calyculin A, pressure had no significant effect. The sequential application of NEM and calyculin A clamped the transporter at about 30% of maximal flux compared to NEM alone; pressure also had no further effect. These results suggest that pressure acts on the ...
Discrimination learning and concept formation in the Arabian horse. Discrimination learning and concept formation abilities were investigated in four mature Arabian horses. A series of two-choice discrimination problems were presented on stimulus panels that could open to allow access to food bowls. Selection of the correct stimulus resulted in food reinforcement, and an incorrect choice was not rewarded. The positions of the correct and incorrect stimuli were varied randomly during each test session, and the criterion for learning each problem was 85% correct for two consecutive sessions of 30 or 40 trials. Testing progressed through six discrimination proble...
The history of veterinary dentistry. Part One: From the earliest record to the end of the 18th century. Dental procedures have been performed on animals, particularly horses, since earliest recorded history. In the absence of anesthesia and an understanding of physiology and pathology, treatment often was unnecessary, inappropriate or barbaric. Progress was made very slowly.
Animal traction in South Africa: research priorities in veterinary science. During June 1994, members of numerous organisations with a vested interest in animal traction in South Africa met for a one-day workshop, the initial activity of a Forum on Working Animals. The workshop was sponsored by the Foundation for Research Development in South Africa. The individuals who attended were representatives of academic and government institutions, farmer and civic organisations, and included veterinarians and veterinary scientists, administrators, traction experts from the region and from abroad, agricultural engineers, sociologist, anthropologists and animal welfare experts....
A comparative study of aerobic capacity and fitness in three different horse breeds (Andalusian, Arabian and Anglo-Arabian). Aerobic capacity and fitness was studied in three different horse breeds (Andalusian, Arabian and Anglo-Arabian) using a four-level exercise test of gradually increasing intensity (15, 20, 25 and 30 km/h). The lactate concentration at the first three exercise levels was significantly lower for Arabian and Anglo-Arabian horses relative to Andalusian horses, but similar for the three breeds at the last level. Arabian and Anglo-Arabian horses reached a higher rate than Andalusian horses at plasma lactate concentration of 2 mmol/l (VLA2) and 4 mmol/l (VLA4). Andalusian horses exhibited a significa...
Blood lactate disappearance after maximal exercise in trained and detrained horses. The influence of training on blood lactate concentrations during treadmill exercise and a 40-minute inactive recovery period was examined in seven trained and seven detrained thoroughbred horses. Lactate concentrations were measured in venous blood collected at the end of each exercise state, and at intervals for 40 minutes afterwards. Measurements were made of maximum oxygen uptake (VO2max, ml kg-1 min-1), VLA4 (velocity at which blood lactate concentration was 4 mmol litre-1); LA8 (lactate concentration [mmol litre-1] during exercise at 8 m sec-1), peak lactate (highest lactate concentration...
The mechanical properties of equine third metacarpals as affected by age. Twenty-five pairs of equine third metacarpals (McIII) were collected from horses of varying breeds and ranging in age from 1 d to 27 yr. Standard three-point bending tests were performed on the McIII to obtain comparative data on breaking load (BL), breaking strength (BS), and elasticity (E). Broken bones were reassembled and 2-cm sections cut from the bone 1 cm below the nutrient foramen and at the site of the break. Bone mineral content (BMC) and geometrical properties of these sections were determined. Maximum BMC (17.3 g/2 cm) was reached at 6.0 +/- 1.8 yr of age. Horses in this study achi...
Prostaglandins and sex steroids from corpora lutea of pregnant mares. In vitro studies. To delineate endocrine mechanisms regulating equine luteal function and the possible functional differences between one month and three month corpora lutea of pregnancy (CL), the in vitro basal releases of prostaglandin F (PGF), prostaglandin E2 (PGE2), progesterone, and 17 beta-estradiol by one and three month CL of pregnant mares were evaluated. In addition, the in vitro effects of PGF2 alpha PGE2, progesterone and 17 beta-estradiol on synthesis of prostaglandins (PGs) and sex steroids were studied. PGF, PGE2, and 17 beta-estradiol secretion was higher in one month than in three month CL, wh...
Multiple genotypes of mitochondrial DNA within a horse population from a small region in Yunnan Province of China. mtDNA genotypes of six domestic horses (three adult short horses whose heights are under 1 m and three common domestic horses) from a small region of 15 km2 in Malipo county of Yunnan province of China were investigated by the technique of restriction fragment length polymorphism (RFLP) with 16 restriction endonucleases which recognize 6-bp sequences. An average of 56 fragments for an individual was obtained. Unlike other domestic animals, this population of horses exhibits high mtDNA genetic diversity. Each of the six horses has a specific mtDNA genotype showing a pattern of multiple maternal...
Effect of route of administration and age on the pharmacokinetics of amikacin administered by the intravenous and intraosseous routes to 3 and 5-day-old foals. The suitability of the intraosseous (i.o.) route for drug administration to equine neonates was evaluated in a study comparing the pharmacokinetics of amikacin administered by the i.o. and intravenous (i.v.) routes. Using a cross-over study design amikacin sulphate (7 mg/kg bwt) was administered i.o. or i.v. to 6 healthy foals at 3 and 5 days of age. Amikacin was instantaneously and completely absorbed after i.o. administration, achieving a mean +/- sd peak concentration (34.17 +/- 3.54 micrograms/ml) in the first sample collected 3 min after administration which was not significantly differen...
Body position and direction preferences in horses during road transport. It has been hypothesised that horses have a preference for facing backward in a trailer during road transport in order to minimise shifts of body weight due to accelerations and decelerations. To determine if horses have preferences for facing forward vs. backward in a horse trailer, the authors analysed the percentages of time horses spent in different body positions and directions while standing in a moving or parked horse trailer. Body positions and directions of 8 Thoroughbred geldings were videotaped while horses were transported singly and untethered in a 4-horse stock trailer over a 32 ...
Functional anatomy of tendons and ligaments in the distal limbs (manus and pes). Tendons and ligaments of the equine distal limbs have a prominent anatomic, functional, and clinical importance. This article reviews the descriptive and topographic anatomy of these structures in details. Special information is given about the mechanical properties and functional anatomy of the flexor tendons, accessory ligaments, and third interosseous muscle, as well as about their roles during the standing position and gaits.
