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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.
Evaluation of cardiac phenotype in horses with type 1 polysaccharide storage myopathy. Type 1 polysaccharide storage myopathy (PSSM1), an equine glycogen storage disorder caused by a gain of function mutation (R309H) in the gene encoding glycogen synthase (GYS1), is associated with the accumulation of amylase-resistant alpha-crystalline polysaccharide inclusions within skeletal muscle. Several glycogenoses in humans have a cardiac phenotype, and reports exist of horses with PSSM and polysaccharide inclusions in cardiac muscle. Objective: To investigate the hypothesis that horses with PSSM1 display a cardiac phenotype. Our objectives were to compare plasma cardiac troponin I (cTn...
Variation in foot conformation in lame horses with different foot lesions. Foot conformation in the horse is commonly thought to be associated with lameness but scientific evidence is scarce although it has been shown in biomechanical studies that foot conformation does influence the forces acting on the deep digital flexor tendon (DDFT) and the navicular bone (NB). The aim of this study was to determine the relationships between foot conformation and different types of lesion within the foot in lame horses. It was hypothesised that certain conformation parameters differ significantly between different types of foot lesions. Conformation parameters were measured on m...
Structures of bovine, equine and leporine serum albumin. Serum albumin first appeared in early vertebrates and is present in the plasma of all mammals. Its canonical structure supported by a conserved set of disulfide bridges is maintained in all mammalian serum albumins and any changes in sequence are highly correlated with evolution of the species. Previous structural investigations of mammalian serum albumins have only concentrated on human serum albumin (HSA), most likely as a consequence of crystallization and diffraction difficulties. Here, the crystal structures of serum albumins isolated from bovine, equine and leporine blood plasma are repo...
The genes of all seven CYP3A isoenzymes identified in the equine genome are expressed in the airways of horses. In the present study, we examined the gene expression of cytochrome P450 3A (CYP3A) isoenzymes in the tracheal and bronchial mucosa and in the lung of equines using TaqMan probes. The results show that all seven CYP3A isoforms identified in the equine genome, that is, CYP3A89, CYP3A93, CYP3A94, CYP3A95, CYP3A96, CYP3A97 and CYP3A129, are expressed in the airways of the investigated horses. Though in previous studies, CYP3A129 was found to be absent in equine intestinal mucosa and liver, this CYP3A isoform is expressed in the airways of horses. The gene expression of the CYP3A isoenzymes varied...
Neutrophils are not less sensitive than other blood leukocytes to the genomic effects of glucocorticoids. Neutrophils are generally considered less responsive to glucocorticoids compared to other inflammatory cells. The reported increase in human neutrophil survival mediated by these drugs partly supports this assertion. However, it was recently shown that dexamethasone exerts potent anti-inflammatory effects in equine peripheral blood neutrophils. Few comparative studies of glucocorticoid effects in neutrophils and other leukocytes have been reported and a relative insensitivity of neutrophils to these drugs could not be ruled out. Objective: We assessed glucocorticoid-responsiveness in equine an...
Whole transcriptome analyses of six thoroughbred horses before and after exercise using RNA-Seq. Thoroughbred horses are the most expensive domestic animals, and their running ability and knowledge about their muscle-related diseases are important in animal genetics. While the horse reference genome is available, there has been no large-scale functional annotation of the genome using expressed genes derived from transcriptomes. Results: We present a large-scale analysis of whole transcriptome data. We sequenced the whole mRNA from the blood and muscle tissues of six thoroughbred horses before and after exercise. By comparing current genome annotations, we identified 32,361 unigene cluster...
Tendon regeneration in human and equine athletes: Ubi Sumus-Quo Vadimus (where are we and where are we going to)? Tendon injuries are one of the most common orthopaedic problems in both human and equine athletes. When a damaged tendon heals naturally, it loses a substantial part of the original strength and elasticity. Therefore, tendons recover structurally (reparation) but not functionally (regeneration) after conservative medical or surgical treatment. Since the structure and matrix composition of human and equine tendons share many similarities, the nature of tendon injuries are also strongly comparable in both species. Therefore, the evaluation of regenerative therapies in horses may have application...
Antimicrobial resistance changes in enteric Escherichia coli of horses during hospitalisation: resistance profiling of isolates. The aim of this study was to determine whether hospitalisation of horses leads to increased antimicrobial resistance in equine faecal Escherichia coli isolates. E. coli were cultured from faecal samples of horses on admission and after 7 days of hospitalisation; antimicrobial susceptibility was determined for eight antimicrobial agents. Resistance profiles of E. coli isolates were grouped into clusters, which were analysed to determine resistance patterns. Resistance to 7/8 antimicrobial agents and multi-drug resistance (MDR; resistance to ≥3 antimicrobial classes) were significantly higher ...
Towards a postural indicator of back pain in horses (Equus caballus). Postures have long been used and proved useful to describe animals' behaviours and emotional states, but remains difficult to assess objectively in field conditions. A recent study performed on horses using geometric morphometrics revealed important postural differences between 2 horse populations differing in management conditions (leisure horses living in social groups used for occasional "relaxed" riding/riding school horses living in individual boxes used in daily riding lessons with more constraining techniques). It was suggested that these postural differences may reflect chronic effects...
Morphology of twin and triplet equine conceptuses during weeks 3 and 4 of pregnancy. Twin ovulations are common in horses, but twin pregnancies are rarely carried to term. Theories of how one or both twins is/are naturally eliminated in early pregnancy, termed 'embryo reduction', have been based on ultrasonographic, not morphological, studies. Here we describe conceptuses recovered transcervically between Days 15 and 28 from 31 twin and two triplet pregnancies. Signs of contact between conceptuses were deduced from those seen in one pair that remained attached by their capsules on Day 18. Signs were found on capsules in two of 10 pairs before or during fixation (immobilisation...
Comparative analysis of serotonin in equine plasma with liquid chromatography–tandem mass spectrometry and enzyme-linked immunosorbent assay. Serotonin is regularly measured in equine platelet-poor plasma in research settings. However, reported reference values vary between studies, partially because plasma serotonin concentrations are very low and a reliable and affordable detection method is lacking. A simple, rapid, and sensitive method for serotonin determination in equine platelet-poor plasma using liquid chromatography--tandem mass spectrometry (LC-MS/MS) was developed and validated. Results of a commercially available enzyme-linked immunosorbent assay (ELISA) were compared to the LC-MS/MS results, in order to validate a test ...
Assessing fitness in endurance horses. A field test and a standardized treadmill test were used to assess fitness in endurance horses. These tests discriminated horses of different race levels: horses participating in races of 120 km and more showed higher values of VLA4 (velocity at which blood lactate reached 4 mmol/L) and V200 (velocity at which heart rates reached 200 beats per min) than horses of lower race levels. Un test sur le terrain et un test sur tapis roulant ont été utilisés pour évaluer la condition physique des chevaux d’endurance. Ces tests ont séparé les chevaux de différents niveaux de course : les cheva...
Time-of-flight magnetic resonance angiography (TOF-MRA) of the normal equine head. Noncontrast magnetic resonance angiography (MRA) is widely used in human and small animal medicine. However, this technique has not yet been described in the horse, and compared to other angiographic techniques MRA could be more cost efficient and potentially safer. Objective: The aim of this study was to provide a comprehensive anatomical reference of the normal equine head vasculature using a noncontrast MRA technique, on both low- and high-field MRI. Methods: Five healthy adult horses were examined, 4 with a low-field magnet (0.23T) and the remaining one with a high-field magnet (1.5T). The...
Phylogenetic and structural studies of a novel equine papillomavirus identified from aural plaques. Papillomaviruses (PVs) infect a wide range of animal species and show great genetic diversity. To date, excluding equine sarcoids, only three species of PVs were identified associated with lesions in horses: Equus caballus papillomavirus 1 (EcPV1-cutaneous), EcPV2 (genital) and EcPV3 (aural plaques). In this study, we identified a novel equine PV from aural plaques, which we designated EcPV4. Cutaneous samples from horses with lesions that were microscopically diagnosed as aural plaques were subjected to DNA extraction, amplification and sequencing. Rolling circle amplification and inverse PCR...
Mutations in DMRT3 affect locomotion in horses and spinal circuit function in mice. Locomotion in mammals relies on a central pattern-generating circuitry of spinal interneurons established during development that coordinates limb movement. These networks produce left-right alternation of limbs as well as coordinated activation of flexor and extensor muscles. Here we show that a premature stop codon in the DMRT3 gene has a major effect on the pattern of locomotion in horses. The mutation is permissive for the ability to perform alternate gaits and has a favourable effect on harness racing performance. Examination of wild-type and Dmrt3-null mice demonstrates that Dmrt3 is exp...
Strain impact on equine herpesvirus type 1 (EHV-1) abortion models: viral loads in fetal and placental tissues and foals. Equine herpesvirus-1 (EHV-1) continues to cause both sporadic and epidemic abortions despite extensive vaccination. Lack of progress in the development of protective vaccines may be hindered by the lack of equine abortion models that employ contemporary EHV-1 strains. The objective of our experiments was to compare a contemporary EHV-1 strain with a previously described challenge strain, and to quantify EHV-1 loads in various maternal and fetal tissues. Infection experiments were performed in two groups of 7 pregnant pony mares at 270-290 days of gestation with a contemporary EHV-1 strain (Uni...
Evidence that in vitro susceptibility of CD3+ T lymphocytes to equine arteritis virus infection reflects genetic predisposition of naturally infected stallions to become carriers of the virus. We investigated the correlation between in vitro susceptibility of CD3(+) T lymphocytes to equine arteritis virus (EAV) infection and establishment of persistent infection among 14 stallions following natural infections. The data showed that carrier stallions with a CD3(+) T lymphocyte susceptibility phenotype to in vitro EAV infection may be at higher risk of becoming carriers than those that lack this phenotype (P = 0.0002).
A comparative review of vitamin E and associated equine disorders. Vitamin E is a primary chain-breaking antioxidant that prevents cyclic propagation of lipid peroxidation. Across species, vitamin E is essential for normal neuromuscular function by acting as a potent antioxidant, as well as by modulating the expression of certain genes, inhibiting platelet aggregation and stabilizing plasma membranes. This review focuses on vitamin E structure, absorption, metabolism, current equine dietary recommendations, the interplay between antioxidants and exercise, a discussion of the necessity of vitamin E supplementation in the horse above the Nutritional Research Co...
Lithium dilution, pulse power analysis, and continuous thermodilution cardiac output measurements compared with bolus thermodilution in anaesthetized ponies. This study compares cardiac output (CO) measurements obtained by lithium dilution (LiDCO), pulse power analysis (PulseCO), and continuous thermodilution (CTD) with bolus thermodilution (BTD) in ponies. Methods: Eight isoflurane-anaesthetized Shetland ponies received xylazine, ketamine, and midazolam infusions (0.3, 1.2, and 0.018 mg kg(-1) h(-1), respectively). CO was measured with BTD, CTD, LiDCO, and PulseCO. Lithium was injected into the jugular vein and blood was sampled from the facial artery for lithium detection and this artery was also used for PulseCO. Measurements were obtained durin...
Do horses expect humans to solve their problems? Domestic animals are highly capable of detecting human cues, while wild relatives tend to perform less well (e.g., responding to pointing gestures). It is suggested that domestication may have led to the development of such cognitive skills. Here, we hypothesized that because domestic animals are so attentive and dependant to humans' actions for resources, the counter effect may be a decline of self sufficiency, such as individual task solving. Here we show a negative correlation between the performance in a learning task (opening a chest) and the interest shown by horses toward humans, despit...
Differential expression of TAR DNA-binding protein (TDP-43) in the central nervous system of horses afflicted with equine motor neuron disease (EMND): a preliminary study of a potential pathologic marker. Equine motor neuron disease (EMND) is a neurodegenerative disorder of unknown etiology affecting horses worldwide. Trans-Active Response DNA Binding Protein of 43 kDa (TDP-43) has been reported in the central nervous system (CNS) of several neurodegenerative conditions in humans including Amyotrophic Lateral Sclerosis (ALS) and assumed to play role in the disease. We examined whether horses afflicted with EMND express the TDP-43 in CNS. Ten horses with EMND and 6 controls of different ages and breed we enrolled. Detection of presence of TDP-43 protein in the CNS was analyzed by immunohistoche...
Thyroid hormone concentrations differ between donkeys and horses. Reference intervals for thyroid hormones (TH) concentrations have not been previously established for donkeys, leading to potential misdiagnosis of thyroid disease. Objective: To determine the normal values of TH in healthy adult donkeys and compare them to TH values from healthy adult horses. Methods: Thirty-eight healthy Andalusian donkeys and 19 healthy Andalusian horses from 2 different farms were used. Donkeys were divided into 3 age groups: 11 years and into 2 gender groups. Serum concentrations of fT3, tT3, rT3, fT4 and tT4 were quantified by radioimmunoassay. All blood samples were col...
Pharmacokinetic analysis of topical tobramycin in equine tears by automated immunoassay. Ophthalmic antibiotic therapy in large animals is often used empirically because of the lack of pharmacokinetics studies. The purpose of the study was to determine the pharmacokinetics of topical tobramycin 0.3% ophthalmic solution in the tears of normal horses using an automated immunoassay analysis. Results: The mean tobramycin concentrations in the tears at 5, 10, 15, 30 minutes and 1, 2, 4, 6 hours after administration were 759 (±414), 489 (±237), 346 (±227), 147 (±264), 27.6 (±28.4), 14.8 (±66.6), 6.7 (±18.6), and 23.4 (±73.4) mg/L. Mean tobramycin concentration was maintained abo...
Reproductive performance of Thoroughbred mares in the Waikato region of New Zealand: 1. Descriptive analyses. To describe the reproductive performance of a population of Thoroughbred mares on stud farms in the Waikato region of New Zealand. Methods: A prospective cohort study was performed involving five stud farms in the Waikato region of New Zealand during three consecutive breeding seasons (2006-2008). A total of 1,482 individual mares contributed 2007 mare years and 3,402 oestrous cycles over the three breeding seasons. Mares were served by 87 individual stallions. Results: The mean first-cycle pregnancy rate (FCPR) was 53.6%, the end-of-season pregnancy rate (SPR) was 85.3% and the foaling rate w...
Fecundity of various species of strongylids (Nematoda: Strongylidae)–parasites of domestic horses. The aims of the study were to determine fecundity of several strongylid species parasitizing domestic horses and analyze possible relations between numbers of eggs in female uteri and size of both the eggs and the nematodes as well as the influence of fecundity on proportion of species in the strongylid community. Twenty-five specimens from each of 15 strongylid species (Strongylus vulgaris, Strongylus edentatus, Triodontophorus serratus, Triodontophorus brevicauda, Triodontophorus tenuicollis, Cyathostomum catinatum, Coronocyclus coronatus, Cylicocyclus nassatus, Cylicocyclus insigne, Cylicoc...
Amniotic fluid and blood lactate concentrations in mares and foals in the early postpartum period. Amniotic fluid (AF) lactate concentration and time-dependent changes in blood lactate concentration in mares after parturition have never been evaluated. In this study, the venous blood lactate concentration of mares and foals during the first 72 h of the postpartum period was assessed, and the concentration of lactate in the AF collected during delivery and the utility of its measurement for evaluating the foal's health were investigated. This prospective observational study was carried out on mares attended at delivery. They were divided into mares delivering healthy (Group 1) and sick (Grou...
Structural and oxygen binding properties of dimeric horse myoglobin. Myoglobin (Mb) stores dioxygen in muscles, and is a fundamental model protein widely used in molecular design. The presence of dimeric Mb has been known for more than forty years, but its structural and oxygen binding properties remain unknown. From an X-ray crystallographic analysis at 1.05 Å resolution, we found that dimeric metMb exhibits a domain-swapped structure with two extended α-helices. Each new long α-helix is formed by the E and F helices and the EF-loop of the original monomer, and as a result the proximal and distal histidines of the heme originate from different protomers. Th...
Horse IgG- and ostrich IgY-F(ab’)₂ groups have different affinities for mice erythrocytes and lymphocytes. Implications for avian immunoglobulin therapeutic usefulness. We used high sensitivity and resolution fluorescence microscopy to study the interaction of ostrich IgY, horse F(ab')₂ and horse IgG with mice lymphocyte and erythrocyte plasma membrane. The immunoglobulins were labeled with fluorescein isotiocyanate (FITC). Our results show an interaction of IgY with lymphocyte plasma membrane which does not result in endocytosis of the labeled protein. Less IgG and its F(ab')₂ fraction bind to lymphocytes, and this binding seems to be followed by endocytosis producing a diffuse cytoplasmic fluorescence in most lymphocytes exposed to FITC-IgG or FITC-F(ab...
Transcriptome analyses of bovine, porcine and equine endometrium during the pre-implantation phase. Different reproductive strategies evolved in various mammalian groups to achieve recognition, establishment and maintenance of pregnancy. The complexity of these processes is reflected by a high incidence of embryonic loss during this critical period in many mammalian species. Besides studies in mice and humans a number of transcriptome studies of endometrial tissue samples and also of early embryos have been performed during the pre-implantation phase in cattle, swine and horse to identify genes associated with embryo-maternal interaction. Results of these studies are reviewed and compared be...
Comparison of a 2-step insulin-response test to conventional insulin-sensitivity testing in horses. Equine insulin resistance is important because of its association with laminitis. The insulin-response test is described to diagnose insulin resistance in clinical settings. Practitioners may be reluctant to perform this test because of the time needed for the test and the fear of inducing hypoglycemia. The objective of the study was to compare a 2-step insulin-response test with a complete insulin-response test. A complete insulin-response test was performed on 6 insulin-resistant horses and 6 controls. A 2-step insulin-response test consisting of an intravenous injection of 0.1 IU/kg human i...
