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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.
Differentiating among horse (Equus caballus), donkey (Equus asinus) and their hybrids with combined analysis of nuclear and mitochondrial gene polymorphism. A novel and brief method of differentiating among horse (Equus caballus) and donkey (Equus asinus) and their hybrids (mule, E. asinus x E. caballus and hinny, E. caballus x E. asinus) with combined analysis of nuclear and mitochondrial gene polymorphism (CANMGP) was reported in the present report. A nuclear gene, protamine P1 gene of donkey was sequenced and compared with the known horse sequence from GenBank while a published equid mitochondrial gene, cytochrome b gene of donkey was compared with that of horse. In each of the two genes, a fixed nucleotide substitution within an exon that coul...
Agonist-independent alteration in beta-adrenoceptor-G-protein-adenylate cyclase system in an equine model of recurrent airway obstruction. We examined the inhibitory sympathetic beta-adrenergic mechanisms in peripheral lung, bronchi and trachea of an equine model of recurrent airway obstruction (RAO), to support the hypothesis that the beta-adrenergic receptor dysfunction is not only restricted to cell surface receptor density but rather encompasses a mechanistic defect apart from the receptor, to the intracellular signaling components. The non-asthmatic lung possessed 3.2-fold more beta-adrenergic receptors than bronchi (496 +/- 19.4 vs. 155.1+/- 19.6 fmol/mg protein; P < 0.01) and 6.2-fold higher than in the trachea (79.8 +/...
Genetic markers for stallion fertility–lessons from humans and mice. Our knowledge on the many aspects of mammalian reproduction in general and equine reproduction in particular has greatly increased during the last 15 years. Advances in the understanding of the physiology, cell biology, and biochemistry of reproduction have facilitated genetic analyses of fertility. Currently, there are more than 200 genes known that are involved in the production of fertile sperm cells. The completion of a number of mammalian genome projects will aid in the investigation of these genes in different species. Great progress has been made in the understanding of genetic aberrati...
[EIAV (equine infectious anemia virus): to better understand the lentiviral pathogenesis]. Equine infectious anemia virus (EIAV) is a lentivirus related to HIV (human immunodeficiency virus). EIAV causes a persistent infection characterized by recurring febrile episodes associating viremia, fever and thrombocytopenia. Despite a rapid virus replication and antigenic variation, most animals progress from a chronic stage characterized by recurring peaks of viremia and fever to an asymptomatic stage of infection. The understanding of the correlates of this immune control is of great interest in defining vaccine strategies. Research on EIAV over the last five decades has produced some in...
Immunologic disorders in neonatal foals. Foals live in an environment heavily populated by bacteria, many of which are capable of causing disease. Development of infection,however, is the exception rather than the rule. The ability of the foal to prevent infection by most pathogens is the result of a sophisticated set of defense mechanisms. These defense mechanisms can be divided into adaptive and innate immunity. Innate immunity encompasses defense mechanisms that pre-exist or are rapidly induced within hours of exposure to a pathogen. Conversely, adaptive or acquired immunity represents host defenses mediated by T and B lymphocytes...
Evaluation of a rebound tonometer for measuring intraocular pressure in dogs and horses. To compare intraocular pressure (IOP) measurements obtained with a rebound tonometer in dogs and horses with values obtained by means of applanation tonometry and direct manometry. Methods: Prospective study. Methods: 100 dogs and 35 horses with clinically normal eyes, 10 enucleated eyes from 5 dogs, and 6 enucleated eyes from 3 horses. Methods: In the enucleated eyes, IOP measured by means of direct manometry was sequentially increased from 5 to 80 mm Hg, and IOP was measured with the rebound tonometer. In the dogs and horses, results of rebound tonometry were compared with results of applana...
Immunoglobulins and immunoglobulin genes of the horse. Antibodies of the horse were studied intensively by many notable immunologists throughout the past century until the early 1970's. After a large gap of interest in horse immunology, additional basic studies on horse immunoglobulin genes performed during the past 10 years have resulted in new insights into the equine humoral immune system. These include the characterization of the immunoglobulin lambda and kappa light chain genes, the immunoglobulin heavy chain constant (IGHC) gene regions, and initial studies regarding the heavy chain variable genes. Horses express predominately lambda light c...
Sequence analysis of canine and equine ferritin H and L subunit cDNAs. Canine and equine ferritin H and L subunit cDNA clones were obtained using reverse transcriptase-polymerase chain reaction (RT-PCR) and TA cloning from various tissues. Canine liver and spleen ferritin H subunit cDNA clones contained an open reading frame for the same 182-amino acid protein as that reported in canine brain ferritin H subunit cDNA although there were substitutions in the 3'-noncoding regions. Ferritin L subunit cDNA clones from canine liver, spleen, and kidney showed identical coding sequences encoding the 174-amino acid protein except for a single nucleotide substitution in ki...
Fluorescence spectra and measurement of phylloerythrin (phytoporphyrin) in plasma from clinically healthy sheep, goats, cattle and horses. To measure the background concentration of phylloerythrin in plasma from clinically healthy sheep, goats, cattle and horses on pasture. Methods: Blood samples were taken from 34 sheep of the Dala breed, 20 female Norwegian dairy goats, 35 Norwegian Red cows and 34 horses of different breeds. All animals were grazing green pasture when blood samples were taken. Blood samples were collected from each of four clinically healthy newborn lambs, goats, calves and foals, and pooled into one sample per species. Plasma samples were analysed for phylloerythrin by fluorescence spectroscopy, using a Perki...
Endoscopic observations on laryngeal symmetry and movements in young racing horses. An endoscopic survey of young race horses was performed to examine the prevalence and character of laryngeal movements during quiet respiration. The main aim was to determine whether those arytenoid movements which could possibly reflect the efficiency of left dorsal cricoarytenoid muscle function changed over a period of time. Of the 452 horses examined, 439 were Thoroughbreds and 23 were Standardbreds, 250 were less than 2 years of age (6-21 months), and 202 were 2 years old. One hundred and nine of these horses were examined again 16 months later. Arytenoid movements were given one of four ...
The effects of polyester (terylene) fibre implants on normal equine superficial digital flexor tendon. To determine the effect of polyester (terylene) fibre implants on normal equine superficial digital flexor (SDF) tendon structure. Methods: Normal forelimb SDF tendons (n=24) of 12 horses were divided into unoperated, sham-operated, and implanted (terylene fibre implant) groups. Horses were assessed for lameness and ultrasonographic changes to SDF tendons at intervals up to 48 weeks post-operatively. After euthanasia, SDF tendons were collected for histological and ultrastructural examination. Histological sections were examined for alcian blue staining intensity, cellularity, fibril bundle al...
End-to-end jejuno-ileal anastomosis following resection of strangulated small intestine in horses: a comparative study. Small intestinal resection and anastomosis is a relatively common procedure in equine surgical practice. This study was designed to test objectively the subjective opinions of surgeons at the Liphook Equine Hospital that an end-to-end jejuno-ileal anastomosis (JIA) is an effective and clinically justifiable procedure, contrary to conventional recommendations. Objective: An end-to-end JIA carries no greater risk of morbidity and mortality than an end-to-end jejunojejunal anastomosis (JJA). Methods: A retrospective observational study was performed on a population of 100 horses that had undergon...
The synovial response to exogenous phospholipid (synovial surfactant) injected into the equine radiocarpal joint compared with that to prilocaine, hyaluronan and propylene glycol. To determine the effects of the intra-articular injection of surface-active phospholipid in a propylene glycol carrier on synovial fluid composition and joint function of horses, and to compare these effects with those observed after the intra-articular administration of prilocaine, hyaluronan and propylene glycol alone. Methods: Twenty-four horses were randomly allocated to four treatment groups: Group 1 100 mg of surface-active phospholipid in 1 ml of propylene glycol; Group 2 1 ml of propylene glycol; Group 3 10 ml of prilocaine; Group 4 2 ml of hyaluronan. Left radiocarpal joints were inje...
Prediction of foaling using mammary secretion constituents. To test published models for predicting time of foaling using data derived from prepartum mammary secretions and to develop a new model based on concentrations of mammary secretion constituents that accurately predicts time of foaling in Thoroughbred mares. Methods: Concentrations of sodium, potassium, calcium, citrate and lactose were measured in prepartum mammary secretions of 20 Thoroughbred mares in the 2 weeks before expected date of foaling. Models to predict time of foaling were fitted to data based on absolute concentration, change in concentration, and percentage change in concentrati...
Short-term survival after surgery for epiploic foramen entrapment compared with other strangulating diseases of the small intestine in horses. Epiploic foramen entrapment (EFE) is one of the more common causes of colic in horses, but recent reports suggest a poor prognosis after surgical treatment. Objective: That EFE has a good prognosis compared with other small intestinal strangulating lesions. Methods: Surgical findings, surgical procedures and short-term outcome were recorded for 157 horses that underwent surgery for strangulating lesions of the small intestine at the University of Illinois from 1994 to 2003. Horses were assigned to 3 groups for comparison; those with EFE, strangulation by lipoma and miscellaneous strangulating ...
Structure of myelin P2 protein from equine spinal cord. Equine P2 protein has been isolated from horse spinal cord and its structure determined to 2.1 A. Since equine myelin is a viable alternative to bovine tissue for large-scale preparations, characterization of the proteins from equine spinal cord myelin has been initiated. There is an unusually high amount of P2 protein in equine CNS myelin compared with other species. The structure was determined by molecular replacement and subsequently refined to an R value of 0.187 (Rfree=0.233). The structure contains a molecule of the detergent LDAO and HEPES buffer in the binding cavity and is otherwise ...
Risk factors for musculoskeletal injuries of the lower limbs in Thoroughbred racehorses in New Zealand. To investigate risk factors for injury to musculoskeletal structures of the lower fore- and hind-limbs of Thoroughbred horses training and racing in New Zealand. Methods: A case-control study analysed by logistic regression was used to compare explanatory variables for musculoskeletal injuries (MSI) in racehorses. The first dataset, termed the Training dataset, involved 459 first-occurrence cases of lower-limb MSI in horses in training, and the second, the Starting dataset, comprised a subset of those horses that had started in at least one trial or race in the training preparation that ended ...
Ocular parameters related to drug delivery in the canine and equine eye: aqueous and vitreous humor volume and scleral surface area and thickness. To measure the ocular surface area, scleral thickness, and the aqueous and vitreous humor volumes in the canine and equine eye. Animals studied Fourteen canine and 16 equine cadaver eyes. Methods: Eyes were measured either fresh or following fixation in formalin. Ocular surface area was calculated using the fluid displacement method. Globes were hemisected and aqueous and vitreous humor were collected and quantitated. Scleral thickness was measured by digital caliper, by image projection, and by ultrasonic biomicroscopy (UBM). Results: Mean +/- standard deviation (SD) scleral surface areas in ...
Characterization of an A-kinase anchor protein in equine spermatozoa and examination of the effect of semen cooling and cryopreservation on the binding of that protein to the regulatory subunit of protein kinase-A. To determine whether a homologue of A-kinase anchor protein 4 (AKAP4) is present and functional as an AKAP in equine spermatozoa and examine the effect of semen cooling and cryopreservation on binding of equine AKAP4 to the regulatory (RII) subunit of protein kinase-A (PK-A). Methods: Ejaculated semen collected from 2 fertile stallions, 3 bulls, and 3 humans. Methods: Identification of an equine homologue of AKAP4 was investigated via DNA sequencing. Protein was extracted from the spermatozoa of each species for immunoblot analysis to identify AKAP4 and its precursor protein, pro-AKAP4; immuno...
Genomic diversity among equine herpesvirus-4 field isolates. Infection with equine herpesvirus-4 (EHV-4) is a major cause of respiratory tract disease, equine rhinopneumonitis, in horses. Although the full sequence of EHV-4 has been reported, genomic differences among EHV-4 field isolates have not yet been characterized. In this study, the genomic diversity between 23 Japanese EHV-4 isolates was analyzed by digestion with restriction endonucleases (BamHI, BgIII, EcoRI, SacI, and SalI) and polymerase chain reaction (PCR). The restriction endonuclease digestion patterns of the EHV-4 field isolates showed distinct differences which included mobility shifts...
Changes in malondialdehyde concentrations and glutathione peroxidase activity in purebred Arabian mares with endometritis. Endometritis is an important factor in infertility. Free radicals play an important role in endometritis and we have investigated their possible role and scavenging systems in endometritis in purebred Arabian mares. The plasma concentration of malondialdehyde (MDA) and erythrocyte glutathione peroxidase (GPx) activity were compared in healthy mares and in mares with endometritis. The level of MDA was significantly increased while GPx activity was decreased in the mares with endometritis. Our findings support the notion that GPx is consumed by increased lipid peroxidation in purebred Arabian ma...
Thoracolaryngeal reflex latencies in Thoroughbred horses with recurrent laryngeal neuropathy. Electrolaryngeography was used to study the latencies of the thoracolaryngeal adductor reflex in Thoroughbred horses with and without recurrent laryngeal neuropathy (RLN). Latencies were compared in horses with grades 1 and 2 RLN, diagnosed by endoscopy in resting horses. The reliability of the measurements, effect of sedation and correlations of latencies with age of the horse were also studied. There was no effect of sedation on reflex latency periods. The latency of the reflex period measured to a convolved peak of the electromyographic response was significantly different in horses with gr...
Femoral asymmetry in the Thoroughbred racehorse. To investigate the occurrence of geometrical asymmetries in the macro-architecture of left and right femurs from Thoroughbred racehorses previously used in competitive training and racing in New South Wales, Australia. Methods: Detailed postmortem measurements were made of 37 characteristics of left and right femurs from eleven Thoroughbred racehorses euthanased for reasons unrelated to the study. Measurements focused on articulating surfaces and sites of attachment of muscles and ligaments known to be associated with hindlimb locomotion. Results: Five measurements were significantly larger in...
An in vitro study on spontaneous myometrial contractility in the mare during estrus and diestrus. Uterine smooth muscle specimens were collected from euthanatized mares in estrus and diestrus. Longitudinal and circular specimens were mounted in organ baths and the signals transcribed to a Grass polygraph. After equilibration time and 2 g preload, their physiologic isometric contractility was recorded for a continuous 2.0 h. Area under the curve, frequency and time occupied by contractions were studied. Differences between cycle phases, between muscle layers, and over the recorded time periods were statistically evaluated using linear mixed-effect models. In the mare, physiologic contractil...
Effect of maximal dynamic exercise on exhaled ethane and carbon monoxide levels in human, equine, and canine athletes. Exercise-induced oxidative stress (EIOS) refers to a condition where the balance of free radical production and antioxidant systems is disturbed during exercise in favour of pro-oxidant free radicals. Breath ethane is a product of free radical-mediated oxidation of cell membrane lipids and is considered to be a reliable marker of oxidative stress. The heatshock protein, haem oxygenase, is induced by oxidative stress and degrades haemoglobin to bilirubin, with concurrent production of carbon monoxide (CO). The aim of this study was to investigate the effect of maximal exercise on exhaled ethane...
Muscle distribution of sylvatic and domestic Trichinella larvae in production animals and wildlife. Only a few studies have compared the muscle distribution of the different Trichinella genotypes. In this study, data were obtained from a series of experimental infections in pigs, wild boars, foxes and horses, with the aim of evaluating the predilection sites of nine well-defined genotypes of Trichinella. Necropsy was performed at 5, 10, 20 and 40 weeks post inoculation. From all host species, corresponding muscles/muscle groups were examined by artificial digestion. In foxes where all Trichinella species established in high numbers, the encapsulating species were found primarily in the tongu...
Endometritis in the mare: a diagnostic study comparing cultures from swab and biopsy. The objective of this study was to compare results from endometrial culture swabs with results from culturing of endometrial biopsies. The culture results were related to cytological findings (polymorphonuclear; PMN-cells) and histological observations (PMN-cells). Biopsy and swab samples were smeared on the surface of a blood agar petri dish, and examined for growth of bacteria. Cytology samples were obtained from endometrial biopsies, stained and examined under microscopy for the presence of PMN-cells. Endometrial biopsies were examined for the presence of PMN-infiltration of the endometrial...
Myosin heavy chain isoforms in equine gluteus medius muscle: comparison of mRNA and protein expression profiles. The major structural protein in skeletal muscle, myosin heavy chain (MyHC), is primarily transcriptionally controlled. We compared the expression of MyHC isoforms on the mRNA and protein level in biopsies from the m. gluteus medius from adult untrained horses. In transverse sections, the majority of fibers showed qualitatively identical mRNA and protein expression patterns. However, coexpression of 2a and 2d/x MyHCs was substantially more common at the protein than at the mRNA level, suggesting a fine-tuning of these two genes in normal muscle not subjected to any training protocol. Because tr...
Detection and comparison of nitric oxide in clinically healthy horses and those with naturally acquired strangulating large colon volvulus. The objective of the study was to determine whether nitric oxide (NO) is present in clinically healthy horses (control) under basal conditions, and if it increases secondary to naturally acquired strangulating large colon volvulus (affected). Eleven affected horses and 10 controls were studied. Jugular venous blood, abdominal fluid, and urine were collected. The NO concentrations were standardized to the creatinine concentration in the respective samples. A biopsy specimen collected from the large colon pelvic flexure at surgery was divided into subsections for processing for inducible nitric ...
