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Topic:Comparative Study
Comparative studies in equine research involve the systematic analysis of different horse breeds, management practices, or physiological responses to identify variations and similarities. These studies are instrumental in understanding how different factors influence health, performance, and behavior in horses. Common areas of comparison include genetic traits, nutritional requirements, disease resistance, and response to training. By evaluating these differences, researchers can develop targeted strategies for breeding, healthcare, and training. This page aggregates peer-reviewed research studies and scholarly articles that focus on the methodologies, findings, and implications of comparative studies in the context of equine science.
Effect of short-term exercise training on insulin sensitivity in obese and lean mares. Twelve untrained aged mares were used to determine whether 7 days of light exercise improved peripheral tissue insulin sensitivity. Mares were divided into obese-exercised (n = 3), obese-sedentary (n = 3), lean-exercised (n = 3) and lean-sedentary (n = 3) groups. The exercised groups were worked at a trot to a heart rate (HR) of not more than 140 beats/min for 30 min in a round pen. Each group was subjected to 3 euglycaemic hyperinsulinaemic clamps: prior to exercise (P), 24 h following the seventh exercise training session (E) and 9 days postexercise training (PE). Prior to exercise training,...
Effect of body incline on cardiac performance. Maximal cardiac performance is improved in man during upright compared to supine exercise. Whether cardiac performance in quadrupeds is dependent upon body position is unknown. Therefore, we undertook the present investigation to determine if peak cardiac output (Qpeak) would be influenced by body inclination in the Thoroughbred horse. To test the hypothesis, four Thoroughbred horses performed an incremental exercise protocol (speed increased by 1 m/s/min to fatigue) on both a level (L) and inclined (I: 6 degrees) treadmill. Specifically, we hypothesised that Qpeak would be increased on the in...
The effect of coat clipping on thermoregulation during intense exercise in trotters. The aim of this study was to study the physiological, especially thermoregulatory, responses during intense exercise in the clipped horse compared to the horse with winter coat. Six Standardbred trotters were studied before and after clipping. They performed an inclined incremental high intensity treadmill exercise test and were monitored during recovery. The clipped horse differed significantly (ANOVA) during exercise as compare to coated: less increase in central venous blood temperature, higher skin surface temperature, greater difference skin to ambient temperature and higher rate of nonev...
Relationship between velocity and temporal variables of the flat shod running walk. The running walk of the Tennessee Walking Horse is often described as a faster variation of the walk, indicating the importance of velocity on the mechanics of the gait. Variations in gait variables create difficulties in clearly identifying the normal and abnormal running walk in a clinical evaluation. The objectives of this study were, therefore, to describe the flat shod running walk and to determine the relationship between velocity and the running walk. From frame-by-frame analysis of 60 Hz film, temporal variables were averaged for 6 strides from 6 horses performing an 'easy' (slow) and ...
Comparison of the effects of two GnRH antagonists on LH and FSH secretion, follicular growth and ovulation in the mare. The effects of two GnRH antagonists were tested in order to delay and/or synchronise ovulation in mares. Five mares received Antarelix (0.01 mg.kg(-1)), 5 mares received Cetrorelix (the same dose), 5 mares (control mares) received the vehicle intravenously, twice daily, for 8 days from the day the largest follicle reached 22 mm following prostaglandin administration. Ovulation was postponed in all mares injected with Antarelix (19.4 +/- 1.2 days after the beginning of the treatment) and in 2/5 mares injected with Cetrorelix (20 +/- 1 days) vs. 6.2 +/- 0.4 days in control mares. During the trea...
Effect of walking velocity on forelimb kinematics and kinetics. A database of biomechanical variables obtained from normal horses walking at a range of velocities is needed for comparison with the variables obtained from lame horses in which velocity cannot be predetermined. The objective was to investigate velocity-dependent changes in selected kinematic variables, ground reaction forces (GRF) and net joint energies in the forelimb and to develop statistical equations to calculate expected values of these variables for horses walking at different velocities. Five sound horses walked at a range of velocities (0.82 to 1.91 m/s) over a force plate. Kinematic...
Quantitative analysis of the organization of the inner nuclear layer of the horse retina. Four cell types including the bipolar, amacrine, horizontal and Muller cells were investigated quantitatively in the inner nuclear layer of the retina in the horse. Cells were identified on the basis of the morphology and distribution of processes leaving from their somata, cytological features and positional features. The average percentages of the above 4 cell types were 44%, 24%, 1% and 29%, respectively. The average total cell densities in the inner nuclear layer in the visual streak, the nasal and temporal regions, the dorsal and ventral regions of the retina were also estimated. It is ex...
Infusion of guaifenesin, ketamine, and medetomidine in combination with inhalation of sevoflurane versus inhalation of sevoflurane alone for anesthesia of horses. To evaluate effects of infusion of guaifenesin, ketamine, and medetomidine in combination with inhalation of sevoflurane versus inhalation of sevoflurane alone for anesthesia of horses. Methods: Randomized clinical trial. Methods: 40 horses. Methods: Horses were premedicated with xylazine and anesthetized with diazepam and ketamine. Anesthesia was maintained by infusion of guaifenesin, ketamine, and medetomidine and inhalation of sevoflurane (20 horses) or by inhalation of sevoflurane (20 horses). A surgical plane of anesthesia was maintained by controlling the inhaled concentration of sevoflu...
Clinical comparison of xylazine and medetomidine for premedication of horses. To compare the analgesic and cardiopulmonary effects of medetomidine and xylazine when used for premedication of horses undergoing general anesthesia. Methods: Randomized clinical trial. Methods: 40 horses. Methods: Twenty horses were premedicated with medetomidine (10 microg/kg [4.5 microg/lb], i.m.) and the other 20 were premedicated with xylazine (2 mg/kg [0.9 mg/kg], i.m.). Horses were then anesthetized with a combination of guaifenesin and ketamine; anesthesia was maintained with halothane. Additional doses of medetomidine or xylazine were given if horses were not sufficiently sedated at ...
Comparison of paste and suspension formulations of omeprazole in the healing of gastric ulcers in racehorses in active training. To compare effects of a commercially available omeprazole paste and a compounded omeprazole suspension on healing of gastric ulcers in Thoroughbred racehorses in active training. Methods: Randomized controlled trial. Methods: 32 horses with gastric ulcers. Methods: Horses were assigned to 2 groups on the basis of endoscopic gastric ulcer severity. Group-1 horses were treated with omeprazole suspension for 30 days and with omeprazole paste for an additional 30 days. Group-2 horses were treated with omeprazole paste for 30 days and omeprazole suspension for an additional 30 days. Serum omeprazol...
Lack of parthenogenesis by Amblyomma cajennense (Acari: Ixodidae). Some reproductive parameters of adult stages of Amblyomma cajennense ticks were studied. The capacity of virgin females to reproduce by parthenogenesis was evaluated, during an experimental infestation, in absence of males, on a horse (Equus cabalus). Ticks were spread either completely free or in limited sites on the body of the animal. The engorged virgin females showed longer feeding periods and lighter body weights than those that had been fertilized. Some of these unmated females produced smaller egg masses, which had no embryonary development. On the other hand, females that had been ins...
Concentrations of inhibin, progesterone and oestradiol in fluid from dominant and subordinate follicles from mares during spring transition and the breeding season. Dominant and subordinate follicles were collected from mares on the day after the dominant follicle reached 30 mm in diameter, to investigate regulation of folliculogenesis during spring transition and the breeding season. Concentrations of oestradiol-17beta, progesterone and inhibin A, but not inhibin isoforms with pro- and alpha C-immunoreactivity, were significantly higher in preovulatory follicles than in dominant anovulatory transitional follicles. Steroidogenic activity was regained gradually in the dominant follicles of successive anovulatory waves through spring transition. The dominan...
Kinetic barriers to the folding of horse cytochrome C in the reduced state. To determine the kinetic barrier in the folding of horse cytochrome c, a CO-liganded derivative of cytochrome c, called carbonmonoxycytochrome c, has been prepared by exploiting the thermodynamic reversibility of ferrocytochrome c unfolding induced by guanidinium hydrochloride (GdnHCl), pH 7. The CO binding properties of unfolded ferrocytochrome c, studied by 13C NMR and optical spectroscopy, are remarkably similar to those of native myoglobin and isolated chains of human hemoglobin. Equilibrium unfolding transitions of ferrocytochrome c in the presence and the absence of CO observed by both e...
Comparison of computed radiography and conventional film-screen radiography of the equine stifle. Major advantages of computed radiography are the potential reduction of dose and the possibility of postprocessing. In our study, we compared conventional radiographs to digital radiographs of the equine stifle by subjective evaluation of diagnostic quality when using a decreasing photon flux (mAs). Twelve equine stifle joints from horses of different weight and size were examined. Conventional and digital radiographs were performed identically in a caudocranial projection with the tube angled 15 degrees. A series of four radiographs was performed in each technique with an increasing photon fl...
Use of multisite quantitative ultrasonography for noninvasive assessment of bone in horses. To evaluate the usefulness of multisite quantitative ultrasonography for noninvasive assessment of bone in horses. Methods: 12 healthy horses and both forelimbs from 8 clinically normal horses. Methods: For in vivo measurements, various regions of interest (ROI) were examined on the third metacarpal bone, radius, and tibia. Precision error for speed of sound (SOS) measurements was obtained by measuring each ROI of 4 horses 10 times with probe repositioning. Additionally, 3 operators measured each aspect of the third metacarpal bone of 6 horses 5 times each. For ex vivo measurements, third meta...
Sensitivity and specificity of western blot testing of cerebrospinal fluid and serum for diagnosis of equine protozoal myeloencephalitis in horses with and without neurologic abnormalities. To determine sensitivity and specificity of western blot testing (WBT) of CSF and serum for diagnosis of equine protozoal myeloencephalitis (EPM) in horses with and without neurologic abnormalities. Methods: Prospective investigation. Methods: 65 horses with and 169 horses without neurologic abnormalities. Methods: CSF and serum from horses submitted for necropsy were tested for Sarcocystis neurona-specific antibody with a WBT. Results of postmortem examination were used as the gold standard against which results of the WBT were compared. Results: Sensitivity of WBT of CSF was 87% for horses w...
Cytogenetic localization of 136 genes in the horse: comparative mapping with the human genome. The aim of this study was to increase the number of type I markers on the horse cytogenetic map and to improve comparison with maps of other species, thus facilitating positional candidate cloning studies. BAC clones from two different sources were FISH mapped: homologous horse BAC clones selected from our newly extended BAC library using consensus primer sequences and heterologous goat BAC clones. We report the localization of 136 genes on the horse cytogenetic map, almost doubling the number of cytogenetically mapped genes with 48 localizations from horse BAC clones and 88 from goat BAC clon...
Immunohistochemical localization of chromogranin a in the acinar cells of equine salivary glands contrasts with rodent glands. We investigated the existence of chromogranin A (CgA) in salivary glands of the horse by Western blotting and enzyme immunoassay (EIA) using an antiserum against a peptide sequence of equine CgA. We also compared its cellular distribution between the horse and rat salivary glands with a tyramide signal amplification immunofluorescence technique. Western blotting gave three significant immunoreactive bands (74, 56 and 48 kDa) in adrenal medulla and three major salivary glands of horses. Immunoreactivities for CgA measured by EIA in horses were 154.05 +/- 41.46, 20.32 +/- 5.59 and 4.43 +/- 2.23 ...
Comparative structural and functional studies of avian and mammalian hemoglobins. Thermal stabilities of chicken, grey lag goose (Anser anser), turkey as avian hemoglobins (Hbs); and human, bovine, sheep and horse as mammalian Hbs in hemolysate form were investigated and compared with oxygen affinities taken from literature. The thermal stability was obtained from thermal profiles using temperature scanning spectrophotometry. The buffer conditions were 50 mM Tris, pH 7.2, and 1 mM EDTA. The average of the inverse temperature transitions, average hydrophobicity, total van der Waals volume, partial molal volume and hydration potential were calculated by computational methods....
Fluoride concentrations in thoroughbred horses in India. Fluoride possesses both essential and toxic potentials. A cross-sectional study recorded the fluoride concentrations in sera of thoroughbred horses 5y of age from 4 localities in India. A total of 628 serum samples of were analyzed for fluoride content using ion selective potentiometry. The mean serum fluoride was estimated as 0.018 +/- 0.002, 0.096 +/- 0.004, 0.16 +/- 0.008 and 0.32 +/- 0.02 ppm in horses from the eastern, central. western and southern parts of the country respectively. Although there were significant difference in fluoride concentration among horses from different zones, all...
Reclassification of equine isolates previously reported as Actinobacillus equuli, variants of A. equuli, Actinobacillus suis or Bisgaard taxon 11 and proposal of A. equuli subsp. equuli subsp. nov. and A. equuli subsp. haemolyticus subsp. nov. Members of Bisgaard taxon 11 have been isolated from horses. These bacteria are of importance in the veterinary clinic and also to the medical profession, since they may be isolated from infected wounds of humans bitten by horses. Six strains from different continents were identified as taxon 11, with 16S rRNA similarities between 98.0 and 99.7%. A single isolate that represented the so-called (+)L-arabinose-positive Actinobacillus equuli isolated from a diseased foal showed 99.9% 16S rRNA similarity to the type strain of A. equuli. DNA-DNA hybridizations showed that (+)L-arabinose-positive st...
Longitudinal development of kinematics in shetland ponies and the influence of feeding and training regimes. Nowadays, ponies are used more and more for competitive equine sports, driving and racing. The locomotor performance of ponies, however, has been evaluated in only a few kinematic and kinetic studies. To compare the longitudinal development of locomotor characteristics in the pony to the same process in the horse, the kinematics of 23 Shetland ponies were recorded at the trot on a treadmill (3 m/s) at ages 4 and 30 months using a modified CODA-3 apparatus. Furthermore, the influence of specific feeding and training regimes on this development was evaluated. It appeared that stride and stance d...
Comparison of lithium dilution and thermodilution cardiac output measurements in anaesthetised neonatal foals. Knowledge of cardiac output is expected to help guide the treatment of hypotension associated with critical illness and/or anaesthesia in neonatal foals. However, a practical and safe method of measuring cardiac output has not been described for the foal. Lithum dilution, a new method of cardiac output determination not requiring cardiac catheterisation, has recently been reported in mature horses. We compared this method to thermodilution in isoflurane-anaesthetised foals age 30-42 h and found good agreement between the 2 methods in a range of cardiac outputs 5.4-20.4 l/min. The lithium dilut...
Distribution and numbers of mucous glands in the horse trachea. Horses commonly suffer from respiratory diseases associated with excess secretions in the airway lumen, some of which are presumably derived from airway mucous glands. However, these structures have been little investigated in the horse. Accordingly, we describe here the number, distribution and size of equine tracheal mucous glands, and compare the data with similar information for other mammalian species. Two types of gland acini were present. In the thick connective tissue, up to 400 microm beneath the epithelium, gland acini were grouped in thin sheets that, in cross-section, averaged 20 m...
Comparison of endoscopic, necropsy and histology scoring of equine gastric ulcers. Equine gastric ulcer syndrome (EGUS) represents a major health problem in performance horses. Much debate exists regarding endoscopic gastric ulcer scoring systems and their ability accurately to predict severity or depth of gastric ulcers. The purpose of this study was to evaluate the ability of an endoscopist to count gastric ulcers and predict gastric ulcer severity or depth using 2 endoscopic scoring systems and compare them to the same gastric ulcers see on necropsy and histopathology. Endoscopic examination of the stomach was performed under general anaesthesia on 23 mixed breed yearling...
Pharmacokinetics of gentamicin C1, C1a and C2 in horses after single intravenous dose. Gentamicin pharmacokinetics has not been studied in horses. Pharmacokinetics of gentamicin C1, C1a and C2 components following i.v. administration of total gentamicin at 6.6 mg/kg bwt to 6 healthy mature horses was determined. Significant differences in clearance, half-life (t 1/2), and mean residence time (MRT) between the gentamicin Cia and the 2 other components were found. The total body clearance (CL) of gentamicin C1a was 1.62 +/- 0.50 ml/min x kg and similar to the glomerular filtration rate (GFR) reported for horses. The CL of gentamicin C1 and C2 were 1.03 +/- 0.08 ml/min x kg and 1.1...
Reliability of ultrasonography compared to radiography in revealing intestinal sand accumulations in horses. In order to investigate the reliability of ultrasonography in revealing intestinal sand accumulations, the cranioventral parts of the abdomen of 32 horses (age 3-20 years) with signs suggestive of gastrointestinal sand were examined radiographically and ultrasonographically. The amount of sand and its localisation, relative to the ventral abdominal wall, were evaluated radiographically and graded (scale 0-4). Motility of the intestine and whether it was lying against the ventral abdominal wall were evaluated ultrasonographically and the findings summed and graded (scale 0-3) to express the lik...
Serum level of cartilage oligomeric matrix protein (COMP) in equine osteoarthritis. This study was designed to assay and compare cartilage oligomeric matrix protein (COMP) in horse sera, in samples from normal and joint diseased horses, and to investigate the relationships between COMP in sera and synovial fluids (SF) with keratan sulphate (KS) data. Sera from 38 horses free of any joint pathology (controls) and from horses with aseptic joint disease (AJD horses, n = 40) were assayed for COMP and KS concentrations. Of the 78 horses in the study, 53 were also assayed for COMP and KS concentrations in SF. COMP and KS were measured by inhibition ELISA, using monoclonal antibodie...
Quantitative motor unit action potential analysis of skeletal muscles in the Warmblood horse. Motor unit action potential (MUP) analysis in human medicine is a valuable and important diagnostic technique enabling discrimination between myogenic and neurogenic problems. This study establishes normative data in subclavian, triceps and lateral vastus muscles for clinical application of MUP analysis in the Warmblood horse, and examines whether muscle differences are present. Electromyographic (EMG) needle examination and MUP analysis were performed of the triceps, lateral vastus and subclavian muscles in 7 awake, nonsedated, Warmblood horses age 4-10 years. The amplitude, duration, number ...
