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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.
T and B lymphocytes in horses persistently infected with equine infectious anaemia virus. The percentage of T and B lymphocytes in the peripheral blood of horses chronically infected with equine infectious anaemia (EIA) virus was determined and the results were compared with the percentage of these cells in healthy uninfected horses. Cells with membrane receptors for sheep erythrocytes (T and active T lymphocytes) were determined by E and A rosette techniques, while cells with receptors for the C3b component of complement and those with receptors for mouse erythrocytes (B lymphocytes), were determined by the EAC rosette method. The percentage of Fe positive cells was assayed by the...
[The radiologic image of the normal equine tarsus]. Normal radiographs of hocks were analyzed for 270 horses (3 views for each hock). They were mainly from young and sound horses. For such animals, the mean number of abnormalities found was 2 to 4.5 for each picture. The mean dimension of certain tarsal bones was measured; geldings had greater bones than mares. An increase of reactions at the origin of the M. interosseus was seen with the age. It was possible to demonstrate that Medichrome films increase the number of discrete abnormalities to be found; this is of particular value for purchase examinations of young horses. The direction of the ...
Equine lymphocyte antigens and reproduction in the Standardbred mare. Equine lymphocyte antigen (ELA) gene frequencies were estimated for pacing and trotting Standardbred mares residing on a breeding farm in central Ohio. The ELA gene frequencies for Ohio Standardbreds did not differ significantly from the ELA gene frequencies of Kentucky Standardbreds, determined by Bailey (1983). No significant differences were found in the distribution of ELA class I antigens in horses with lower overall fertility or a history of abortion on the investigated breeding farm. Likewise, no significant association was observed when the ELA types of both the mare and the stallion t...
Different gradients for neurotransmitter metabolites and protein in horse cerebrospinal fluid. The serotonin metabolite, 5-hydroxyindoleacetic acid (5-HIAA) and the dopamine metabolite, homovanillic acid (HVA) in the cerebrospinal fluid (CSF) of seven clinically normal horses were evaluated with reverse phase high pressure liquid chromatography and electrochemical detection. Comparisons of the neurotransmitter metabolite concentrations were made on CSF collected simultaneously from the atlanto-occipital and lumbosacral regions. There were significantly higher amounts of 5-HIAA and HVA in atlanto-occipital CSF than in lumbosacral CSF. Mean 5-HIAA concentrations in atlanto-occipital and l...
The pony as an animal model for vascular implants. This study evaluated the pony as a potentially suitable model for vascular implant research. Healthy, conditioned ponies were randomly assigned to one of three groups: group I, carotid artery autografts (n = 6); group II, e-PTFE carotid interpositional grafts (n = 5); and group III, e-PTFE carotid interpositional grafts plus aspirin (10 mg/kg) and dipyridamole (3.5 mg/kg) drug administration. It was found that autografts remained patent longest (mean = 396.2 days; grafts were still patent at time of writing) followed by group III grafts (157.5 days), with group II grafts remaining patent for t...
A study of diurnal changes in cortisol and glucose levels and FDPA activity in foals during the first 13 weeks of life and in their lactating mothers. 1. In six standard-bred mares and their foals diurnal changes in the cortisol and glucose levels and in FDPA activity were studies for 13 weeks of foal life. 2. In the cortisol level diurnal rhythm was found in the 3rd, 7th and 11th week of foal life and in the 11th week of lactation in mares. 3. In mares the mean diurnal cortisol level changed from 32 ng/ml in the first week to 57 in the 11th week and in foals from 24 in the first week to 16 ng/ml in the 11th week. 4. In the glucose level no diurnal rhythm was observed. 5. In mares the mean diurnal glucose level after parturition was about 58...
Purification of F(ab’)2 anti-snake venom by caprylic acid: a fast method for obtaining IgG fragments with high neutralization activity, purity and yield. Pooled horse plasma containing antibodies against Crotalus durissus terrificus whole venom were digested with pepsin at an enzyme-substrate ratio of 8:1, pH 3.1, for 40 min and the F(ab')2M fragments purified by adding 8.7% caprylic acid (pH 5.0). For comparison, F(ab')2B purified by precipitation with ammonium sulphate and uncleaved IgG purified with caprylic acid were also prepared. Fab' fragments were obtained by reduction and alkylation of F(ab')2B. The anti-whole C.d. terrificus venom titers, determined by Dot-Blot were 12,800 (IgG), 6400 [F(ab')2B], 4800 [F(ab')2M] and 3200 (Fab'B). Immu...
Comparison of transtracheal aspirate and bronchoalveolar lavage cytology in 50 horses with chronic lung disease. Comparisons were made between transtracheal aspirate (TTA) and bronchoalveolar lavage (BAL) cytology obtained from 50 horses with chronic lung disease and from 10 control horses. There was no significant correlation between the TTA cytology and the BAL cytology, suggesting that the cell population in the trachea is not representative of the cell population in the lower airways. In control horses the range of differential cell counts obtained from TTA fluid was remarkably large, whereas the variability in cell populations observed in BAL fluid was smaller. In the principal horses the total and ...
A preliminary comparison of lidocaine and xylazine as epidural analgesics in ponies. Xylazine (0.35 mg/kg) or lidocaine (0.35 mg/kg) was injected into the epidural space of six ponies to compare their effectiveness as epidural analgesics. Each pony received both treatments at 1 week intervals with the order of treatments randomized. Xylazine produced analgesia of significantly longer duration (247 +/- 58 minutes) than that produced by an equal dose of lidocaine (135 +/- 22 minutes). Mild transient ataxia of no clinical significance developed in all ponies with both treatments. Spinal cords were removed from two ponies and examined histologically. No discernible pathologic chan...
Topography of oxytocin and vasopressin neurons in the forebrain of Equus caballus: further support of proposed evolutionary relationships for proopiomelanocortin, oxytocin and vasopressin neurons. The present study describes the topography of immunoreactive (ir) oxytocin (OXY) and vasopressin (AVP) neurons in the forebrain of Equus caballus and the coexistence of ir proopiomelanocortin (POMC)-derived peptides in the same cells. These data are compared to those for other mammalian species and the possible significance of species variations is considered. As expected, magnocellular neurons of the equine hypothalamus, which contain ir OXY or AVP, have prominent discernible projections to the neurohypophysis. Further, as in other mammalian species, the field of ir OXY perikarya generally ex...
Evaluation of two techniques for large intestinal resection and anastomosis in the horse. Six normal adult horses had large colon resections at the sternal and diaphragmatic flexures. Stainless steel staples were used to close the stumps of the dorsal and ventral colons in all six. Intestinal continuity was restored with a side-to-side anastomosis of the dorsal and ventral colons. Three of these anastomoses were performed with staples, and three with a double inverting suture pattern. After one month, the horses were surgically reevaluated, and the anastomotic sites were examined. There was no significant difference between the stoma sizes in the two groups. No complications were o...
Immunoglobulin concentration in the blood serum of foals suffering from pneumonia associated with mycoplasma infection. Clinical, microbiological, haematological, and immunological investigations were carried out in mares and their foals of 2 studs. A considerable number of foals fell ill with pneumonia, the mortality rate was high. Mycoplasmas were mostly isolated from nasal swabs and from the lungs. The isolation rate of bacteria was lower. Serum IgG concentration was reduced in the diseased or dead foals compared to that of healthy animals, the data stress in importance of IgG in the development of respiratory diseases also in foals.
Prevalence and intensity of non-strongyle intestinal parasites of horses in northern Queensland. A quantitative post-mortem study of 57 horses from northern Queensland was done to determine the prevalence and intensity of non-strongyle intestinal parasites. The following species (% prevalence) were found: Draschia megastoma (39%); Habronema muscae (43%); Gasterophilus intestinalis (34%), G. nasalis (30%); Parascaris equorum (15%); Strongyloides westeri (6%); Probstmayria vivipara (2%); Oxyuris equi (26%); Anoplocephala magna (2%); A. perfoliata (32%). Mean parasite numbers of individual species ranged from 10 to 1310. Prevalence and intensity data were compared to recent studies in Wester...
Gonadotropin releasing hormone (GnRH) affects precopulatory behavior in testosterone-treated geldings. Twelve pony geldings with (n = 6) and without (n = 6) testosterone replacement (200 micrograms/kg testosterone propionate in oil, SC every 48 hours) received either gonadotropin releasing hormone (GnRH; 25 micrograms SC every 3 hours) or control treatment. Sexual behavior was recorded during 4-minute exposure to an estrous mare, 3 times weekly for 2 weeks before treatment, 3 weeks during treatment, and 3 weeks after treatment had been discontinued. The group receiving testosterone and GnRH (n = 3) exhibited significantly greater flehmen response frequency and attention duration and significant...
Comparative effects of cholera toxin, Salmonella typhimurium culture lysate, and viable Salmonella typhimurium in isolated colon segments in ponies. Isolated segments of left dorsal colon and a side-to-side colocolostomy (between the left ventral colon and left dorsal colon) were surgically created in 6 adult ponies. Four segments, each separated by an empty segment, were inoculated (20 ml) with 1 of the following 4 solutions: phosphate buffered saline solution (PBSS)/1% polyethylene glycol (PEG); purified cholera toxin in PBSS/1% PEG (5 micrograms cholera toxin/ml of PBSS/1% PEG); lyophilized Salmonella typhimurium UCD 1755 culture lysate, reconstituted in PBSS/1% PEG; and viable S typhimurium UCD 1755 (10(8) organisms/ml of PBSS/1% PEG)....
[Performance testing of mules and Haflinger horses used as pack animals]. During 20 weeks blood constituents in peripheral blood (Erythrocyte count, Packed cell volume, Hemoglobin, Sedimentation rate, activities of Aspartate aminotransferase, Alanine aminotransferase, Creatine phosphokinase, Lactate dehydrogenase, Lactate dehydrogenase-1-isoenzyme, Glucose, Lactate, Total bilirubin), pulse and respiration rate were determined at rest and after exercise. Significant increase of blood values after exercise could be noted in relation to the intensity of exercise and the performance of the animals. The well trained horses had an increase of their performance according t...
Kinetic and inhibitory characteristics of serum angiotensin-converting enzyme from nine mammalian species. 1. Serum angiotensin-converting enzyme activities were obtained from nine mammalian species: rat, mouse, horse, sheep, guinea pig, hamster, rabbit, dog and man. 2. Kinetic constants (Km and Vmax) using hippuryl-L-histidyl-L-leucine as substrate and inhibitory constants (I50 and Ki) for captopril were determined for the serum ACE of each species. 3. There were important differences in the kinetic and inhibitory constants (Kms went from 6.6 mM to 1.21 mM for hamster and guinea pig; I50 ranged from 2100 nM to 3 nM for mouse and sheep) as well as differences in enzyme activity of the different spe...
A previously reported polymorphic plasma protein of dogs and horses, identified as apolipoprotein A-IV. By using immunoblotting with antiserum specific to human plasma apolipoprotein A-IV (apoA-IV), a previously reported polymorphic plasma protein of dogs viz postalbumin-2 (Pa2) and one of horses viz serum protein 2 (SP2), were identified as apoA-IV of these species. This along with earlier published results implied that: (1) both dog and horse show a high degree of polymorphism at the APOA4 locus with three common alleles in each of the two species; and (2) apoA-IV phenotyping in these two species can be done by analysing plasma/serum samples by a simple method of two-dimensional electrophoresi...
Comparative anatomy of the accessory ciliary ganglion in mammals. The orbits of 13 mammalian species (pig, sika deer, domestic sheep, horse, cat, fox, racoon dog, marten, rat, rabbit, crab-eating macaque, japanese macaque and man) were stained with silver nitrate and dissected under a dissecting microscope with special attention to the presence and location of the accessory ciliary ganglion. Some preparations were stained with thionin and examined as whole-mounts in a transmission microscope. The accessory ciliary ganglion was present in all 13 species, although the number and degree of development varied greatly from species to species. The accessory ciliar...
Comparison of respiratory secretion cytology and pulmonary histology in horses. Equine respiratory secretions (RS) collected before (33 horses) and after (76 horses) slaughter were evaluated cytologically and grouped according to the histological diagnosis of the lungs from which they were obtained. The histological categories included normal lungs (control; 17 horses), chronic small airway disease with mild (23 horses), moderate (13 horses) and severe lesions (25 horses), interstitial pneumonia (13 horses), pulmonary eosinophilic infiltration (13 horses) and pulmonary haemorrhage (5 horses). On a group basis there were significantly more neutrophils in RS of horses with ...
Monoclonal antibody-mediated, immunodiagnostic competitive enzyme-linked immunosorbent assay for equine monocytic ehrlichiosis. Competitive enzyme-linked immunosorbent assay (CELISA), mediated by a monoclonal antibody designated HybI, was developed for the diagnosis of equine monocytic ehrlichiosis. Inhibition of binding of HybI by the horse antibodies to Ehrlichia risticii was optimum at dilutions of 1:20 for serum and 1:10,000 for HybI. Mean optical densities (ODs) of positive and negative sera were 0.158 and 0.855, respectively. A comparison of ODs obtained by CELISA and indirect enzyme-linked immunosorbent assay (ELISA) indicated a marked tendency of positive and negative samples to cluster separately with respect ...
Effects of season and lower ambient temperature on the structure of the sweat glands in anhidrotic horses. Histological studies of the sweat glands of anhidrotic horses in the Hong Kong summer and under conditions of reduced thermal stress, both natural and controlled, were undertaken to determine if glandular regeneration occurs. Clinical data were collected for comparison with the histological results in each instance. Horses were assigned to one of three categories on the basis of the resulting change in the number of thin glandular profiles in a cooler environment. Group 1, which was classed as normal, had a low initial value, which was maintained. Group 2, typical of mild and moderately affect...
Enzymatic deacylations of esterified saccharides–III. Comparison of de-esterifications by serum esterases from different sources. 1. 14C-labelled methyl 2,6-di-O-pivaloyl-alpha-D-glucopyranoside (1) was used as a substrate for esterases from rabbit, guinea pig, mouse, donkey, pig, horse, sheep and human sera. 2. Stepwise de-esterification of the diester substrate 1 occurred with rabbit, guinea pig and mouse serum. Data on time-course experiments and kinetic data are reported. 3. The use of donkey, pig, horse, sheep and human serum led to the migration of the 2-O-pivaloyl group in substrate 1 to the position 4- in the sugar molecule, followed by stepwise de-esterifications of both 1 and the newly formed methyl 4,6-di-O-pi...
Simulation of quadrupedal locomotion using a rigid body model. Locomotion of the horse is simulated using a mathematical model based on rigid body dynamics. A general method to generate the equations of motion for a two-dimensional rigid body model with an arbitrary number of hinge joints is presented and a numerical solution method, restricted to tree-structured models, is described. Joint movements originating from muscular forces or moments are simulated, but the method also allows that parts of the model follow strictly the pattern of kinematic data. Moment-generators with first-order linear feedback were used as a rotational muscle-equivalent. Ground...
Radiographic measurement from the lateromedial projection of the equine foot with navicular disease. Radiographic measurements from the lateromedial projection of the equine foot were compared in three groups of horses. Group 1 consisted of 143 normal horses, group 2 were 60 horses with clinical navicular disease and group 3 were 161 horses with clinical and radiographic navicular disease. Several measurements tended to be larger in group 3 than group 1. An enlargement of the navicular bone was observed in proximodistal and dorsopalmar directions. Partial enlargement of the pedal bone was observed in groups 2 and 3. Few differences were observed between age classes. All horses aged four years...
Fat cell size in various body region. A statistical analysis in Equus caballus. In 13 horses from both sexes, between 5 months and 18 years of age, in good nutritional state, statistical evaluations of fat cell sizes were performed in 16 body regions. From direct and indirect measurements referred to the cell diameter and cell number in equivalent areas, carried out on sections from paraffin embedded material and on preparations of dissociated whole cells, it emerged that the adipose cells of the subserous fat of the abdominal floor are consistently the largest, whereas those of the orbital fat body and supraorbital fossa are the smallest. In the other regions the cells h...
Resistance of mammalian red blood cells of different size to hypertonic milieu. 1. The resistance of different mammalian red blood cells (RBCs) to hyperosmotic environments was studied. RBCs of six mammalian species were exposed to 10 increasingly hyperosmotic NaCl solutions for 24 hr at 5 degrees C. 2. The osmolality at which the amount of liberated haemoglobin reached a preset level (e.g. 3-4% of the total haemoglobin) showed a linear correlation with negative slope with RBC volume. This indicates that small RBCs are more resistant to hyperosmotic milieu than large ones. 3. A similar relation can be found from literature data when maximal urinary tonicities are plotted ...
Alleviation of postanesthetic hypoxemia in the horse. This study was designed to investigate the effect of the nasotracheal insufflation of oxygen at a flow rate of 15 L/min on the arterial partial pressure of oxygen during the recovery period following inhalation anesthesia in the horse. It has been stated that this is a suitable flow rate to prevent postoperative hypoxemia but without any experimental evidence to support those statements. Horses being used for the study of healing of cartilage were anesthetized on two separate occasions. Following one period of anesthesia they were allowed to recover breathing room air, and following the other ...
Use of high-speed cinematography and computer generated gait diagrams for the study of equine hindlimb kinematics. High-speed cinematography with computer aided analysis was used to study equine hindlimb kinematics. Eight horses were filmed at the trot or the pace. Filming was done from the side (lateral) and the back (caudal). Parameters measured from the lateral filming included the heights of the tuber coxae and tailhead, protraction and retraction of the hoof and angular changes of the tarsus and stifle. Abduction and adduction of the limb and tarsal height changes were measured from the caudal filming. The maximum and minimum values plus the standard deviations and coefficients of variations are prese...
The nature of embryo reduction in mares with twin conceptuses: deprivation hypothesis. Ultrasonography was used to determine whether there is embryo reduction in mares with unilaterally fixed twins when a major portion of the vascularized area of the wall of one of the embryonic vesicles is in apposition with the wall of the adjacent vesicle, rather than with the endometrium (deprivation hypothesis). In addition, the effect of ovulatory pattern (synchronous and asynchronous) on the incidence of embryo reduction was studied. Twin vesicles were ultrasonically detected on days 11 to 15 (ovulation = day 0) and were examined daily until there was embryo reduction or until day 40. In ...
