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Topic:Veterinary Research
Veterinary research in horses encompasses the study of diseases, health management, and medical treatments specific to equine species. This field investigates various aspects of horse health, including infectious diseases, metabolic disorders, and musculoskeletal conditions. Researchers focus on understanding the pathophysiology of equine ailments, developing diagnostic tools, and evaluating therapeutic interventions. The study of horse health also involves examining preventive measures such as vaccination protocols and nutritional management to promote overall well-being. This page collects peer-reviewed research studies and scholarly articles that explore the diverse areas of veterinary science related to horses, providing insights into disease mechanisms, treatment strategies, and advancements in equine healthcare.
Temporal changes in the trot between the first and third horse inspections at a CCI*** 3-day event. Kinematic parameters were measured from horses competing in a CCI*** 3-day event. The horses were filmed during the first and third horse inspection. This provided a repeat sample on 16 horses. The horses were filmed using a panning lateral S-VHS video camera (50 Hz). Spatial measurements were taken for mean +/- s.d. 5.66 +/- 0.92 strides for the first inspection and 5.05 +/- 1.27 for the third inspection. Within the calibration zone, data of the horses accelerating and obtaining a constant velocity were collected. The horses trotted with a higher mean velocity during the third inspection (0.2...
Dietary fat supplementation and equine plasma lipid metabolism. Feeding of a fat-rich diet to horses may enhance the flux of fatty acids, in the form of triacylglycerols (TAG), through the circulation into skeletal muscle. This hypothesis was tested indirectly by measuring the concentration of plasma TAG and the activity of lipoprotein lipase (LPL) in post heparin plasma. Six mature horses were fed a high-fat or a control diet according to a crossover design with feeding periods of 6 weeks. The control diet contained 1.5% fat in the dry matter and the high-fat diet 11.8%. The high-fat diet was formulated by adding soybean oil to the control diet at the exp...
Exertional rhabdomyolysis in quarter horses and thoroughbreds: one syndrome, multiple aetiologies. The purpose of this study was to determine if chronic exertional rhabdomyolysis (ER) in Quarter Horses and Thoroughbreds represents one or several distinct myopathies. Eighteen Quarter Horses and 18 Thoroughbreds with ER were selected from cases presented to the Veterinary Hospital on the basis of a history of ER, assessment of muscle histopathology, and serum CK activity before and 4 h post exercise. In addition, 2 of 3 of the following parameters were evaluated: muscle glycogen concentrations, thyroid hormones (T3, T4), fractional excretion (FE) of sodium, potassium and chloride. The CK resp...
In vitro transmission and attenuation of impact vibrations in the distal forelimb. An in vitro model was developed and validated in vivo to quantify the attenuation of impact vibrations, transmitted through the lower equine forelimb and to assess the effects of horseshoeing on this attenuation. The transsected forelimbs of 13 horses were equipped with custom-made hollow bone screws in the 4 distal bones, on each of which a tri-axial accelerometer could be mounted. The limbs were then preloaded while the impact was simulated by dropping a weight on the steel plate on which the hoof was resting. At the hoof wall, the distal, middle and proximal phalanx and at the metacarpal bo...
Influence of training on autonomic nervous function in horses: evaluation by power spectral analysis of heart rate variability. We studied the influence of training on autonomic nervous function in the horse. For this purpose, Holter electrocardiogram (ECG) was recorded before and after training from 24 Thoroughbred horses (2-year-olds) and autonomic nervous function was evaluated by the power spectral analysis of heart rate (HR) variability. We obtained HR, low-frequency (LF) power, high-frequency (HF) power, and LF/HF ratio from recording. We set LF at 0.01-0.07 Hz and HF at 0.07-0.6 Hz. The HF power is thought to reflect primarily parasympathetic nervous function. Both the sympathetic and parasympathetic nervous sys...
Cardiac output measurements using sonomicrometer crystals on the left ventricle at rest and exercise. Eight horses were fitted surgically with 8 ultrasonic sonomicrometer crystals each attached to their left ventricular pericardia and a left atrial catheter. Three horses returned to treadmill performance with a maximum rate of oxygen consumption similar to their presurgical values. These horses were evaluated to determine how well sonomicrometer estimates of cardiac output agreed with those obtained by a steady-state method, the Fick principle. Variance between the 2 was similar to the coefficient of variation (approximately 12.5%) of the Fick estimates. We conclude that left ventricular sonom...
Radiographic measures of bone shape in young thoroughbreds during training for racing. The aim of this study was to determine if changes in the shape of the third metacarpal bone (MC3) during the first preparation for racing in young Thoroughbred racehorses could be measured radiographically. Lateral radiographs of each MC3 were taken when the horses commenced training, every 2 weeks for 10 weeks, and again at 6 months after the start of training. The width of the dorsal cortex (DC), palmar cortex (PC), and medulla (M) were measured at a position 2.5 cm distal to the nutrient foramen before the subject of each radiograph was identified. The following ratios were calculated: z = ...
Effect of breathing frequency and airflow on pulmonary function in high-intensity equine exercise. It has been postulated that the hypoxaemia and hypercapnoea that characterize strenuous equine exercise are partly due to flow limitations imposed by high breathing frequencies (fb), and that gas exchange would be improved if fb could be lowered. To evaluate this possibility, 6 Thoroughbred horses underwent 4 incremental treadmill exercise tests at inclines of 0, 5, 10 and 25%, respectively. In the test, horses were given a warm-up for 2 min, then ran sequentially for 1 min each at 60, 100 and 115% VO2max. Oxygen consumption (VO2), blood gas tensions (PaO2, PaCO2), fb, tidal volume (VT), minut...
The effect of shoeing on kinetics and kinematics during the stance phase. The increasing range of of horseshoes and hoofpads makes it important to be able to evaluate their influence on performance and stress in the locomotor apparatus. The aim of this study was to describe the changes in ground reaction forces and locomotion pattern during the stance phase due to the application of a standard iron shoe. Six Swedish Warmblood horses were evaluated kinetically and kinematically before and after they were shod with an 8 mm iron shoe. Data were used to calculate ground reaction forces in the vertical and craniocaudal directions, point of application of the force, hoof ...
Changes in left ventricular dynamics during graded exercise. Three mature Thoroughbred horses were prepared surgically with ultrasonic sonomicrometer crystals affixed to their ventricular pericardia. Signals from crystals recorded dimensions of axes across the left ventricle. Cubic algorithms were fitted to dimensional data to generate volume estimates that matched stroke volumes simultaneously measured using the Fick principle. As horses stood at rest or exercised at various intensities (approx 7, 12, 24, 47 and 100% maximal rate of O2 consumption VO2max[), left ventricular dimensions were recorded and 20 consecutive diastolic and systolic volumes calc...
An MRI study of the effect of treadmill training on bone morphology of the central and third tarsal bones of young thoroughbred horses. Training results in marked modelling of the subchondral bone of the carpus, but the effect of training on the subchondral bone of the distal tarsal joints is unknown. The aim of this study was to determine whether training influenced modelling of the third and central tarsal bones in Thoroughbred horses. Twelve untrained Thoroughbred horses were divided into 2 groups. Group 1 underwent a 19 week progressive training regimen on a high speed treadmill. Group 2 were walked for 40 min daily. Images of left tarsi were obtained by magnetic resonance imaging (MRI) with a 0.5 Tesla superconducting mag...
Endocrine response to exercise in young and old horses. Six young (mean + s.e., 5.3 +/- 0.8 years, 445 +/- 13 kg bwt) and 6 old (22.0 +/- 0.4 years, 473 +/- 18 kg bwt) Standardbred and Thoroughbred mares were used to test the hypothesis that age would alter the endocrine response to exercise. All of the mares were unconditioned but accustomed to the laboratory, to standing quietly and running on a treadmill, and to the standardised incremental exercise test (SET) used in the experiment. Two weeks prior to the experiment, each horse underwent a SET to determine maximal oxygen uptake (VO2max) and the speeds to be used in the actual experiment. A seco...
Heritability of percentage of fast myosin heavy chains in skeletal muscles and relationship with performance. The purpose of this study was to determine the percentage of fast myosin heavy chains (fast MHCs = MHC 2A + 2B) in 2 propelling muscles to estimate the heritability and to identify any relationship with performance. The gluteus medius and the biceps femoris muscles were biopsied in 100 related French Anglo-Arabian horses. The percentages of slow and fast myosin heavy chains were measured using an ELISA technique. The heritability (s.e.) of the fast MHCs percentage was estimated at 13% (0.1) using a restricted maximum likelihood resolution of a mixed animal model. There were significant (P < 0....
Contributions of equine exercise physiology research to the success of the 1996 Equestrian Olympic Games: a review. Following public concern about the weather conditions for the 1996 Olympic Games in Atlanta an international research programme was initiated. The primary objective of this effort was to identify strategies for ensuring welfare of horses competing in the heat. Field observations of horses during the endurance test of 3-day events in Europe, Canada, and the USA characterised the work effort of this form of competition; laboratory treadmill studies assessed limitations to performance of heat and humidity, explored the relationships of thermoregulatory demands to the phases of the competition and...
The effect of training on the calcified zone of equine middle carpal articular cartilage. Carpal osteochondral injury is frequently observed in strenuously trained horses. It is clear that the integrity of articular cartilage and subchondral bone are intimately related, although there is controversy about which component is the most important. Calcified cartilage provides the mechanical link between soft hyaline cartilage and stiff subchondral bone so it is essential to understand the tissue's response to exercise. Middle carpal calcified and uncalcified (hyaline) cartilage thickness was investigated in horses undergoing high- and low-intensity exercise. Twelve untrained horses (18...
Relationship of body condition score to completion rate during 160 km endurance races. Three-hundred and sixty horses, primarily of Arabian breeding, age 5-22 years and body conditions scores 1.5-5.5 (on 1 to 9 scale as described by Henneke 1985), participated in one of two 160 km endurance races over the same course in August 1995 and July 1996. Condition score, cannon bone circumference, combined rider and tack weight, heart girth and body length were measured 11-18 h prior to the start of the event and bodyweight estimated according to the formula by Carroll and Huntington (1988). A rider weight ratio was calculated as rider weight divided by horse bodyweight. Rider weight an...
[Functional morphology of the large intestinal mucosa of horses (Equus przewalskii f. caballus) with special regard to the epithelium]. The mucous membrane of the caecum and colon ascendens of adult horses was first studied using light and transmission electron microscopy. In the surface epithelium there was an inconspicuous constellation of organelles, otherwise there was a lot of mitochondria as a source of energy for absorptive performances. Moreover, enlarged intercellular spaces exist as an indication of an increased uptake of water and electrolytes. In the basal region of Lieberkühn's crypts there were single enteroendocrine cells and numerous granules in the apical epithelial cytoplasm. The functional meaning of these ...
The teeth of the horse: evolution and anatomo-morphological and radiographic study of their development in the foetus. The aim of this work was to study the ontogenetic process in teeth from their early appearance in the ossifying matrix of the mandible and maxilla, in different foetuses of scalar ages. Radiographic examinations of the skull and mandible hemisections were performed and the latero-medial (LM) and dorsoventral (DV) projections for the skull and mandible were analysed. A high-definition film-screen combination was used for this study. The exposure values ranged from 35 kV/6 mAs to 58 kV/10 mAs, according to the size of the skulls and their degree of ossification. The first dental germ observed wa...
An in vitro biomechanical investigation of an equine interlocking nail. To determine the mechanical properties of Equine Interlocking Nail (EIN; JD Wheat Veterinary Orthopedic Research Laboratory, University of California, Davis) stabilized osteotomized tibiae and compare these variables with estimated in vivo loads. Methods: In vitro biomechanical investigation. Methods: Twelve adult equine cadaveric tibiae. Methods: EIN-stabilized tibiae were tested monotonically under compression, 3- and 4-point bending, and torsion. Mechanical properties were compared with estimated in vivo loads. Results: EIN-tibial composite mean compressive yield load (11 kN) and bending mo...
Growth characteristics of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies. To determine if there is a difference in in vitro growth of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies. To determine the effects of a corticosteroid and monokine on in vitro growth of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies. Methods: Growth of fibroblasts from tissues harvested from the trunk and limb were compared from horse and pony samples grown in control media and control media with triamcinolone or monokine added. Methods: Dermal and subcutaneous tissue from 22 horses and 17 ponies of various ages ...
Thoughts on the source of tissue on subsequent cell culture success. This paper describes attempts to initiate equine adipocyte cultures from necropsy cases with varying intervals from time of death to isolation and culture. Equine adipocytes were isolated from 21 necropsy cases, regardless of the interval from time after death to establishment in primary ceiling cultures. However, while all cultures produced adipocytes, only 2 attempts to produce long-term equine adipocyte cultures from the subcutaneous rump fat depots were successful and not contaminated. Findings from these experiments indicate that it is possible to collect and culture equine adipocytes fro...
Development of a PCR test for rapid diagnosis of contagious equine metritis. In order to establish a rapid diagnostic method for contagious equine metritis (CEM), we developed and evaluated a polymerase chain reaction (PCR) test. Species-specific PCR primer sets were derived from the DNA sequence of a cloned DNA fragment of Taylorella equigenitalis that did not hybridize with the genome of a taxomonically related species, Oligella urethralis. Single step PCR with primer set P1-N2 and two-step semi-nested PCR with primer sets P1-N2 and P2-N2 detected as low as 100 and 10 CFU of the bacteria, respectively. Single-step PCR detected T. equigenitalis from genital swabs of e...
Veterinary vaccinology. Veterinary vaccinology is a very interesting and rapidly developing field. In fact veterinary vaccines are not only used for the prevention of infectious diseases in the animal health sector, but also help to solve problems of public health, to reduce detrimental environmental impact of the use of some veterinary drugs and prevent the emergence of resistance of micro-organisms or parasites. After a short introduction, this paper will deal with the use of vaccines for animal health and welfare, including new developments in the veterinary field such as marker vaccines and vectored vaccines, the...
Changes in equine endometrial oestrogen receptor alpha and progesterone receptor mRNAs during the oestrous cycle, early pregnancy and after treatment with exogenous steroids. Two experiments were performed to determine changes in the abundance of oestrogen and progesterone receptor (ER alpha and PR) mRNAs in equine endometrium during the oestrous cycle and early pregnancy, and under the influence of exogenous steroids. In Expt 1, endometrial biopsies were obtained from non-mated mares during oestrus and at days 5, 10 and 15 after ovulation, and from pregnant mares at days 10, 15 and 20 after ovulation. There were overall effects of day on the abundance of ER alpha (P = 0.0001) and PR (P = 0.0014) mRNAs. The amount of ER alpha mRNA decreased at day 10 of pregnancy, ...
Expression of CRISP proteins in the male equine genital tract. Cysteine rich secretory proteins (CRISPs) have been detected immunochemically in the equine male genital tract. CRISPs are secretory products of the epididymis, the ampulla and the seminal vesicle. A particular feature of the horse is the abundance of CRISPs in seminal plasma. CRISPs can also be detected in extracts of testicular, epididymal and ejaculated spermatozoa in increasing amounts. Unlike other seminal plasma proteins, they cannot be removed completely from spermatozoa by high salt treatment. The remaining CRISP antigens are localized on the midpiece, and the postacrosomal and equator...
Characterization of cellular and vascular changes in equine follicles during hCG-induced ovulation. In contrast to other species, the histology of the equine follicle during ovulation has not been described. Preovulatory follicles were isolated during oestrus at 0, 12, 24, 30, 33, 36 and 39 h (n = 5-6 follicles per time point) after an ovulatory dose of hCG to characterize the cellular and vascular changes associated with ovulation in mares. Pieces of follicle wall were formalin-fixed and processed for light microscopy to evaluate the general follicular morphology and quantify selected parameters. Marked changes were observed in the histology of equine follicles in the hours before ovulation...
Cell proliferation patterns during development of the equine placenta. Placentation involves considerable growth and reorganization of both maternal and fetal tissues. In this investigation, immunohistochemical localization of the proliferation marker Ki-67 antigen was used to monitor cell division during placentation in mares. Endometrial biopsies were obtained from eight mares between day 14 and day 26 of pregnancy and from eight anoestrous mares that had been treated with various combinations of progesterone and oestrogen. Samples of endometrium and fetal membranes were obtained from 19 mares carrying normal horse conceptuses between day 30 and day 250 of gest...
Analyses of TCRB rearrangements substantiate a profound deficit in recombination signal sequence joining in SCID foals: implications for the role of DNA-dependent protein kinase in V(D)J recombination. We reported previously that the genetic SCID disease observed in Arabian foals is explained by a defect in V(D)J recombination that profoundly affects both coding and signal end joining. As in C.B-17 SCID mice, the molecular defect in SCID foals is in the catalytic subunit of the DNA-dependent protein kinase (DNA-PKCS); however, in SCID mice, signal end resolution remains relatively intact. Moreover, recent reports indicate that mice that completely lack DNA-PKCS also generate signal joints at levels that are indistinguishable from those observed in C.B-17 SCID mice, eliminating the possibilit...
In vitro and in vivo evaluation of hypericin for photodynamic therapy of equine sarcoids. The therapeutic potential of the photodynamic compound, hypericin, in the treatment of equine sarcoids was evaluated. The in vitro cytotoxicity was assessed using three equine cell lines and the observed phototoxic effect was comparable to that on different highly sensitive human cell lines and significantly influenced by the energy density used although independent of the cell type. The in vivo antitumoural action of photodynamic therapy using hypericin was evaluated on three equine sarcoids in a donkey. Four intratumoural injections were given and the tumours were illuminated daily during 25...
Replication of equine herpesvirus type 1 in freshly isolated equine peripheral blood mononuclear cells and changes in susceptibility following mitogen stimulation. In the present study, the outcome of an inoculation of equine peripheral blood mononuclear cells (PBMC) with equine herpesvirus type 1 (EHV-1) was studied in vitro. Cytoplasmic and plasma membrane expression of viral antigens, intra- and extracellular virus titres, and plaque formation in co-culture were determined. EHV-1 replicated in monocytes, although in a highly restricted way. Viral antigens were found at maximum levels (8.7% of the monocytes) at 12 h post-infection. The infection was productive in 0.16% of the monocytes. The virus yield was 10(0.7) TCID(50) per productive cell. In a pop...
