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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.
The reappearance of strongyle eggs in the faeces of horses after treatment with moxidectin. The reappearance of strongyle eggs in the faeces of horses treated with moxidectin (0.4 mg/kg of body weight) was compared with that in the faeces of horses treated with ivermectin (0.2 mg/kg of body weight). The study was performed from December 1995 till June 1996. Horses were infected naturally in the preceding grazing period. Two groups of 24 horses each were treated with moxidectin and ivermectin respectively at week 0. No side effects were seen after treatment. Horses were housed from week -1 till week 17. From week 17 onwards the horses were on pasture. Faecal samples were taken from ea...
Comparative efficacy of moxidectin 2% equine oral gel and ivermectin 2% equine oral paste against Onchocerca cervicalis (Railliet and Henry, 1910) microfilariae in horses with naturally acquired infections in Formosa (Argentina). On the basis of positive skin snips for Onchocerca cervicalis microfilariae (MF), 45 horses were chosen from 48 in a total of 257 screened on 12 locations in the northeast Province of Formosa (Argentina), and randomly assigned to two treatment groups of 20 horses each, and a nontreated control group of five horses. On Day 14 post-treatment (PT), skin snip samples in the ivermectin-treated (0.2 mg/kg) group were negative for normal viable microfilariae (MF), while horses in the control group maintained their pretreatment level of infection. On the same Day in the moxidectin-treated (0.4 mg/kg) ...
[Demonstration of immunoglobulin isotypes in the vitreous body as a contribution to the etiology of recurrent equine uveitis]. The functional properties of different immunoglobulin isotypes in equine recurrent uveitis (ERU) has not been investigated yet. Here, we describe the quantitative determination of total immunoglobulin levels and isotype differentiation in the vitreous of four horses with ERU as compared to that of seven healthy horses. In contrast to almost equal amounts of total immunoglobulin in the vitreous of both groups, remarkable differences were found: All four of the horses with ERU had significantly higher IgA contents in their vitreous as compared to the control group. However, the other isotypes mo...
Morphometric study of the equine navicular bone: comparisons between fore and rear limbs. Navicular bones collected from the four limbs of 95 sound horses were studied. The anatomic bases have been laid down about morphometry of the navicular bones and their variations according to limbs, after corrections have been made for morphologic type, gender, weight, size and age. All the dimensions of the navicular bone (except for the thickness) were larger in the fore limb. This phenomenon probably reflects an attempt to compensate for the greater forces exerted upon the fore limbs during exercise and at rest. Navicular bones collected from the four limbs of 61 sound horses were studied ...
The effects of partial thyroidectomy on the development of the equine fetus. A syndrome of congenital hypothyroidism and dysmaturity has been an important cause of reproductive loss and foal mortality in western Canada. The cause and pathogenesis of this syndrome is under investigation. One issue to be addressed is whether all the anomalies present in affected foals are produced concurrently by the same agent, or if affected foals are primarily hypothyroid in utero which induces the associated lesions. This study was designed to document the effects of fetal thyroidectomy, at about 215 days of gestation, on the growth and development of the equine fetus and to compare ...
Neurotrophin receptor-like proteins in Peyer’s patches. The neurotrophins are a family of growth factors that act on responsive cells through specific high-affinity signal-transducing receptors called Trk (A, B, and C) proteins. The neurotrophin receptor proteins are widely distributed in both nervous and nonnervous tissues, including the lymphoid organs. The expression of these receptor proteins by a cell population is an indication of responsiveness to the respective binding neurotrophin. The present study investigated the presence and cellular localization of high-affinity neurotrophin receptor proteins in equine and bovine Peyer's patches. Peye...
Exercise-related alterations in crimp morphology in the central regions of superficial digital flexor tendons from young thoroughbreds: a controlled study. Injury to the core of the mid-metacarpal region of the superficial digital flexor tendon in Thoroughbred racehorses is a very frequent but poorly understood condition. It has been suggested that subclinical changes induced by galloping exercise weaken the collagen in this region of the tendon, predisposing it to rupture. The longitudinally arranged collagen fibrils in tendon follow a planar waveform, termed the crimp. Fibril bundles with a smaller crimp angle fail at a lower level of strain than those with a larger crimp angle. This study tested the hypothesis that a specific 18 month exercise...
Biomechanical implications of mineral content and microstructural variations in cortical bone of horse, elk, and sheep calcanei. Artiodactyl and perissodactyl calcanei have been recently introduced as models for examining bone for mechanically mediated adaptation. We have reported substantial regional variations in cortical bone microstructure and mineral content within the same cross-section of mule deer calcanei. In part, these variations may be adaptations accommodating the customary presence of predominantly tension, compression, and shear strain modes in mutually exclusive cortical locations. Calcanei from skeletally mature horses, elk, and sheep were examined in order to corroborate these previous findings. From e...
Pharmacokinetics and cardiopulmonary effects of guaifenesin in donkeys. Five donkeys and three horses were given guaifenesin, intravenously, by gravity administration, until recumbency was produced. The time and dose required to produce recumbency, recovery time to sternal and standing were recorded. Blood samples were collected for guaifenesin assay at 10, 20, 30, 40, 50, 60 min, and 2, 3, 4 and 6 h after guaifenesin administration. Serum was analysed for guaifenesin using HPLC and pharmacokinetic values were calculated using a computer software package (RSTRIP). In donkeys, heart and respiratory rates and blood pressures were recorded before and at 5-min interva...
Fourier-transform infrared spectroscopic studies on the coordination of the side-chain COO- groups to Ca2+ in equine lysozyme. Interactions between Ca2+ and the Asp side chains in the Ca2+-binding site of equine lysozyme were investigated by Fourier-transform infrared (FT-IR) spectroscopy. In the spectrum of equine lysozyme, the intensities of the bands at about 1595 cm-1 and 1578 cm-1 in the region of the COO antisymmetric stretches increased upon Ca2+ binding. In the region of the COO- symmetric stretches, the loss of intensity at about 1388 cm-1 and gains of intensities at about 1423 cm-1 and 1403 cm-1 were observed due to Ca2+ binding to equine lysozyme. The spectral changes for equine lysozyme indicate that the C...
Genetic variation of envelope gp90 gene of equine infectious anemia virus isolated from an experimentally infected horse. Six strains of equine infectious anemia virus (EIAV) were recovered from febrile and non-febrile stages of a horse experimentally infected with the P337-V70 strain given once to a horse. The env gp90 genes of the isolates, the P337-V70 and P337-V26, avirulent virus derived from the P337-V70 strain, were sequenced. A comparison of the gp90 gene sequences revealed that amino acid variations among the viruses tested showed as high as 8.2 to 11.5%. In addition, the comparison also indicated that the isolates that recovered from the non-febrile stage were contained in nucleotide insertions in the p...
Biomechanical comparison of the Herbert and AO cortical bone screws for compression of an equine third carpal bone dorsal plane slab osteotomy. To assess feasibility of insertion of 4.5-mm Herbert cannulated bone screws (HS) using fluoroscopic guidance and compare the mechanical shear strength of these HS and 4.5-mm AO cortical bone screws (AO) for fixation of dorsal plane slab osteotomies in equine cadaver third carpal bones (C3). Methods: Eight equine cadavers. Methods: Bone mineral composition and density of contralateral C3 were confirmed to be equivalent using dual-energy x-ray absorptiometry. A standard 10-mm C3 slab osteotomy was reduced using HS or AO instrumentation under fluoroscopic guidance. Specimens were loaded in shear ...
[Analysis of the distribution of ribosomal RNA genes on chromosomes of the domestic horse (Equus caballus) using fluorescent in situ hybridization]. Distribution of blocks of ribosomal RNA genes along metaphase chromosomes of 26 horses from five breeds was determined by means of a modified method of fluorescence in situ hybridization (FISH) in combination with simultaneous R- banding. Gene loci coding for rRNA were mapped to the region of secondary constriction on the short arm of chromosome 1, and to the pericentromeric regions of chromosomes 27, 28, and 31. The nucleolar organizer region (NOR) on chromosome 27 was not described earlier. Interindividual and interchromosomal NOR polymorphism was detected With the use of a semiquantitative ...
In vitro responses to noradrenaline of small intestine taken from normal and grass sickness-affected horses. Small intestine was taken from the caudal flexure of the duodenum and the terminal ileum proximal to the ileocaecal fold of 25 horses, 9 with acute grass sickness (AGS), 12 with subacute grass sickness (SAGS) and 12 with chronic grass sickness (CGS). The motility in the samples was measured isometrically either within 1 h of death or after storage for 24 h at 4 degree C. In control tissue, noradrenaline produced contractions of muscle strips which did not involve a muscarinic cholinergic mechanism and which were unaffected by the alpha 1 antagonist prazosin but were blocked by the alpha 2 anta...
A novel P/V/C gene in a new member of the Paramyxoviridae family, which causes lethal infection in humans, horses, and other animals. In 1994, a new member of the family Paramyxoviridae isolated from fatal cases of respiratory disease in horses and humans was shown to be distantly related to morbilliviruses and provisionally called equine morbillivirus (K. Murray et al., Science 268:94-97, 1995). To facilitate characterization and classification, the virus was purified, viral proteins were identified, and the P/V/C gene was cloned and sequenced. The coding strategy of the gene is similar to that of Sendai and measles viruses, members of the Paramyxovirus and Morbillivirus genera, respectively, in the subfamily Paramyxovirina...
Role of oligosaccharides in the pharmacokinetics of tissue-derived and genetically engineered cholinesterases. To understand the role of glycosylation in the circulation of cholinesterases, we compared the mean residence time of five tissue-derived and two recombinant cholinesterases (injected intravenously in mice) with their oligosaccharide profiles. Monosaccharide composition analysis revealed differences in the total carbohydrate, galactose, and sialic acid contents. The molar ratio of sialic acid to galactose residues on tetrameric human serum butyrylcholinesterase, recombinant human butyrylcholinesterase, and recombinant mouse acetylcholinesterase was found to be approximately 1.0. For Torpedo ca...
Cardiorespiratory effects of sevoflurane, isoflurane, and halothane anesthesia in horses. To determine and compare cardiorespiratory and recovery effects of sevoflurane, isoflurane, and halothane in horses. Methods: 8 clinically normal horses (4 mares, 4 geldings), 5 to 12 years old. Methods: Inhalation anesthesia was maintained for 90 minutes with sevoflurane, isoflurane, or halothane. Anesthesia depth was maintained at 1.5 minimum alveolar concentration of halothane, isoflurane, and sevoflurane, then was reduced at 30 and 60 minutes. A surgical plane of anesthesia was reinduced by administration of ketamine or thiopental or by increasing the fractional inspired concentration of s...
Molecular cloning and cartilage gene expression of equine stromelysin 1 (matrix metalloproteinase 3). To clone and determine molecular structure of equine stromelysin 1 (matrix metalloproteinase 3) and examine stromelysin expression in articular cartilage. SAMPLES AND PROCEDURE: Total RNA was harvested from equine arthritic cartilage specimens and was used for reverse transcription and polymerase chain reaction amplification to develop overlapping complementary DNA (cDNA) clones. Four cDNA sequences were ligated into plasmid (pGEM3Z) constructs and subcloned into bacterial expression vectors, and sequence was determined by automated dye terminator sequencing. Stromelysin mRNA expression was as...
Comparative analysis of equine lymphocyte subsets in whole blood and gradient-purified samples. In the present study, two methods of lymphocyte preparation, whole blood lysis and Ficoll-Paque separation, prior to FACS analysis were compared. The comparison was done with single and dual-colour staining techniques. Monoclonal antibodies (mAb) against eCD4, eCD5, eCD8 and eMHC class II were used. There was no significant difference in the results obtained by these two methods.
Erythrocyte aggregation tendency and cellular properties in horse, human, and rat: a comparative study. Horse blood has a higher tendency to form red blood cell (RBC) aggregates compared with human blood, with this enhanced aggregation previously attributed to differences in plasma factors. Our results confirm this observation and further indicate that washed horse RBC also have a significantly higher aggregation tendency in dextran 70 solutions (i.e., horse RBC have a higher "aggregability"). In contrast, the aggregation tendency of rat RBC, both in autologous plasma and in dextran 70, is significantly less compared with human and horse RBC. Other rheological findings for horse and rat RBC incl...
Zoo-FISH with microdissected arm specific paints for HSA2, 5, 6, 16, and 19 refines known homology with pig and horse chromosomes. Microdissected arm specific paints (ASPs) for human (HSA) chromosomes (Chrs) 2, 5, 6, 16, and 19 were used as probes on pig (SSC) and horse (ECA) metaphase chromosomes. Regions homologous to individual human arms were delineated in the two species studied. Of the ten ASPs used, HSA6 and 16 ASPs showed complete synteny conservation of individual arms as single blocks/ arms both in pig and horse. A similar trend was, in general, also observed for HSA19 ASPs. However, contrary to these observations, synteny conservation of individual arms of HSA2 and HSA5 was not observed in pig and horse. The ar...
Study of the heart rate and energy expenditure of ponies during transport. The energy expenditure and heart rate of five Shetland ponies were measured during transport and compared with the values recorded while they were at rest and walking. Secondary aims of the study were to investigate whether there was any correlation between heart rate and energy expenditure and whether different orientations affected the values to different degrees. The measurements were recorded at one-minute intervals while the ponies were at rest, walking and being transported in four different orientations, on journeys lasting 30 minutes. There were significant increases (P < 0.001) in ...
Histological investigations on the skin of the mammary gland of mares. The purpose of the study was to give a histological picture of the different skin regions of the mammary gland in mares. Special emphasis on the dark coating in the sulcus intermammarius was given. As a result, the dark pigmented udder skin can be subdivided into the skin of the Corpus mammae, the sulcus intermammarius and the teat skin. In the sulcus intermammarius the whole epidermis was considerably thicker than usual, especially the stratum corneum (up to 70 layers of cornified layers) and the stratum spinosum. In general, the squamous keratinocytes were unusually large. The histological p...
Kinematic symmetry index: a method for quantifying the horse locomotion symmetry using kinematic data. This study was conducted to evaluate a method for quantifying locomotion symmetry at trot in sound and lame horses. Using a 3D kinematic analysis system, the kinematics of the limb joints of sound and lame horses were recorded. The differences in motion between the left and right homologous joints were then quantified using a symmetry index based on an inter-correlation method. This method was used to calculate the symmetry indices of the vertical displacements and angle-time diagrams of the joints of each horse. In order to evaluate the sensitivity of this method of quantifying the locomotion...
Comparison of nucleic and amino acid sequences and phylogenetic analysis of open reading frames 3 and 4 of various equine arteritis virus isolates. The genetic variation in equine arteritis virus (EAV) protein-encoding open reading frames (ORFs) 3 and 4 genes was investigated. Nucleic and deduced amino acid sequences from seven different EAV isolates (one European, one American and five Canadian isolates) and the Arvac vaccine strain were compared with those of Bucyrus reference strain. ORF 3 nucleotide and amino acid sequence identities between these isolates (including the Arvac vaccine strain) and the Bucyrus reference strain ranged from 85.6 to 98.8%, and 85.3 to 98.2%, respectively, whereas ORF 4 nucleotide and amino acid sequence id...
Total protein and immunoglobulin concentrations in equine tears. Lacrimal fluid represents a major ocular surface defensive mechanism providing different concentrations of all immunoglobulin classes. In this report, four classes of immunoglobulins (IgA, IgM, IgG and IgGT) have been measured in horse tears. As in others species, IgA is the main immunoglobulin responsible for local protection and constitutes quantitatively, 50% of all lacrimal proteins. The rest of immunoglobulins studied are normally present in equine tear fluid (though in lower concentration) and contribute to ocular surface immune protection. Female and adult horses showed significant high...
Purification and characterization of equine testicular cytochrome P-450 aromatase: comparison with the human enzyme. Cytochrome P-450 aromatase was purified by five chromatographic steps from adult stallion testis. It was first separated from NADPH-cytochrome P-450 reductase (reductase) on omega-aminohexyl-Sepharose 4B then purified to homogeneity on concanavalin A-Sepharose 4B, hydroxyapatite-Sepharose 4B, DEAE-Sepharose CL-6B and on a second hydroxyapatite-Sepharose 4B. On the other hand, purifications of the equine testicular and rat liver reductases, which allowed the reconstitution of aromatase activity in vitro, were achieved for each species in one chromatographic step on an adenosine 2',5'-diphosphat...
