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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.
Anterior and posterior segment photography. An alternative approach using a dSLR camera adaptor. To describe a novel digital single lens reflex (dSLR) camera adaptor for anterior and posterior segment photography. Methods: The adaptor was used to evaluate canine, feline, and equine patients presenting to Tufts Ophthalmology service. Anterior segment imaging was conducted with the adaptor mounted between a dSLR camera body (Canon 7D) and a macro lens (Canon EF-S 60mm/f2.8). Posterior segment imaging was performed with the aid of an indirect ophthalmic lens mounted in front of the macro lens. Coaxial illumination during viewing was provided by a single white light-emitting diode (LE...
Biomechanical testing of a novel suture pattern for repair of equine tendon lacerations. To compare in vitro biomechanical properties of a novel suture pattern to a current standard for primary repair of equine superficial digital flexor tendon (SDFT) laceration. Methods: In vitro randomized, paired design. Methods: Cadaveric equine forelimb SDFT (n = 24). Methods: The 3-loop pulley (3LP) and 6-strand Savage (SSS) suture patterns were applied to transected equine SDFT. Ultimate failure load, stiffness, mode of failure, and load required to form a 3-mm gap were obtained using a materials testing system and synchronized high-speed video analysis. Statistical comparisons were made us...
Overexpression of histidine-rich calcium binding protein in equine ventricular myocardium. Histidine-rich calcium binding protein (HRC) is a high capacity, low affinity Ca(2+) binding protein, specifically expressed in striated muscles of mammals. In rabbit skeletal and cardiac muscles, HRC binds to sarcoplasmic reticulum (SR) membranes via triadin, a junctional SR protein. Recently, a potential role in heart failure and arrhythmogenesis has been assigned to HRC due to its activity as regulator of SR Ca(2+) uptake and Ca(2+) release. HRC might play a particularly relevant role in the equine heart, given its slower resting heart rate (20-35 beats/min) and longer action potential dura...
Expression of high-molecular-mass neurofilament protein in horse (Equus caballus) spinal ganglion neurons. Spinal ganglion (SG) neurons are subdivided, on the basis of their cytoplasmic aspect at light and electron microscopy, into dark (D) and light (L) neurons. Numerous efforts have been made to find specific markers able to identify D and L neuronal cytotypes. The isolectin B4 (IB4), utilized to identify nonpeptidergic D neurons in mice, unfortunately, has not proved as effective in other species. The 200-kDa neurofilament protein (NF200) is considered as a typical marker of L neurons in the rat, cat, and chick. The aim of this study was to analyze the histological, morphometric, and neurochemic...
Basal glucose metabolism and peripheral insulin sensitivity in equine pituitary pars intermedia dysfunction. Glucocorticoids are suggested to precipitate laminitis and induce insulin resistance in horses. Objective: To assess insulin sensitivity and the basal amount of glucose metabolized in equine pituitary pars intermedia dysfunction (PPID). Methods: The euglycaemic hyperinsulinaemic clamp (EHC) technique was performed in seven horses with a diagnosis of PPID based on the presence of hypertrichosis and positive dexamethasone suppression-test results comprising one gelding and six mares with a mean age of 21.1 ± 5.8 (SD; range 15-34) years. Results were compared with those from five negative (h...
Genetic differences in the serum proteome of horses, donkeys and mules are detectable by protein profiling. Although horses and donkeys belong to the same genus, their genetic characteristics probably result in specific proteomes and post-translational modifications (PTM) of proteins. Since PTM can alter protein properties, specific PTM may contribute to species-specific characteristics. Therefore, the aim of the present study was to analyse differences in serum protein profiles of horses and donkeys as well as mules, which combine the genetic backgrounds of both species. Additionally, changes in PTM of the protein transthyretin (TTR) were analysed. Serum protein profiles of each species (five anima...
Inhibition of cytochrome P450 enzymes involved in ketamine metabolism by use of liver microsomes and specific cytochrome P450 enzymes from horses, dogs, and humans. To identify and characterize cytochrome P450 enzymes (CYPs) responsible for the metabolism of racemic ketamine in 3 mammalian species in vitro by use of chemical inhibitors and antibodies. Methods: Human, canine, and equine liver microsomes and human single CYP3A4 and CYP2C9 and their canine orthologs. Methods: Chemical inhibitors selective for human CYP enzymes and anti-CYP antibodies were incubated with racemic ketamine and liver microsomes or specific CYPs. Ketamine N-demethylation to norketamine was determined via enantioselective capillary electrophoresis. Results: The general CYP inhibit...
Comparison of plasma and peritoneal indices of fibrinolysis between foals and adult horses with and without colic. To identify hemostatic imbalances indicative of an increased risk of intra-abdominal adhesion formation in foals versus adult horses. Methods: Horses with colic undergoing exploratory laparotomy or abdominocentesis as part of a clinical examination (n = 16 foals ≤ 6 months of age and 19 adults ≥ 5 years of age) and horses without colic undergoing herniorrhaphy (15 foals) or euthanasia for noninflammatory and nongastrointestinal disease (10 foals and 20 adults). Methods: Paired abdominal fluid and blood samples were collected from each horse into buffered sodium citrate and centrifuged imme...
Molecular and cytogenetic studies in a case of XX SRY-negative sex reversal in an Arabian horse. An 18-month-old Arabian foal characterized by a stallion-like appearance was submitted for cytogenetic and molecular genetics examinations due to abnormalities of external genitalia and the presence of ovotestis-like structures in the abdominal cavity. By RB-banding the animal showed the normal female equine karyotype (2n = 64,XX). Molecular analysis revealed the absence of the SRY and ZFY genes and the presence of ZFX, a typical female equine condition. The entire RSPO1 coding region was examined to exclude its involvement. Although a SNP was found in exon 3, it was not responsible for an ami...
Transcriptional analysis of equine λ-light chains in the horse breeds Rhenish-German Coldblood and Hanoverian Warmblood. The present study analyzed equine λ-light chain genes (IGLV and IGLC) transcribed in the horse breeds Rhenish-German Coldblood (RGC) and Hanoverian Warmblood (HW). Primers were generated for the major expressed IGLV subgroup 8. The significant majority of the sequences represented IGLC6/7. In RGC, IGLC1 and IGLC5 were observed in significant higher frequencies than IGLC4. In HW, significant differences were obtained for the transcription of IGLC1 and IGLC5. IGLC4 was not determined in this breed. Five allotypic IGLC1 variants, four allotypic IGLC5 variants, and three allelic as well as two al...
Morphometrical variations of the carpal bones in thoroughbreds and ponies. There is scant morphological data for equine carpal bones despite the frequent pathology in Thoroughbreds (TB). This study aimed to identify morphological and morphometrical variations and similarities in carpal bones between and within TB and Ponies (Po). Carpal bones from nine TB and 13 Po were prepared by boiling and drying. Lateromedial width, dorsopalmar depth, proximodistal height, relative density and volume of each bone were measured. Normalized measurements of the radial (Cr) and third (C3) carpal bones were significantly different in all dimensions, and there were significant variati...
MSTN genotype (g.66493737C/T) association with speed indices in Thoroughbred racehorses. Sequence variation at the equine myostatin gene (MSTN) locus has previously been shown to have a singular genomic influence on optimum race distance in Thoroughbred racehorses. Myostatin, encoded by the MSTN gene, is a member of the TGF-β superfamily that regulates skeletal muscle development in a range of mammalian species including the horse. In the Thoroughbred, the C-allele at the g.66493737C/T SNP has been found at significantly higher frequency in subgroups of the population that are suited to fast, short distance, sprint races and also influences body composition phenotypes. We investi...
The combination of purified recombinant human platelet-derived growth factor-BB and equine particulate bone graft for periodontal regeneration. The objective of this study is to evaluate the potential for periodontal regeneration of a critical-sized defect with the application of recombinant human platelet-derived growth factor (rhPDGF-BB) combined with either a particulate equine or a β-tricalcium phosphate (β-TCP) matrix. Methods: Critical-sized intrabony 2-wall defects were created bilaterally on the distal surface of the second premolar and the mesial surface of the first molar in nine hounds. Twelve defects received rhPDGF-BB/equine treatment, 12 defects received rhPDGF-BB/β-TCP treatment, and the remaining 12 sites served as ...
Cytogenetic and molecular characterization of Y isochromosome in a 63XO/64Xi(Yq) mosaic karyotype of an intersex horse. Sex chromosome aberrations commonly lead to abnormal sexual development. Here we cytogenetically and molecularly characterized Y isochromosome in an intersex horse. Blood lymphocyte analysis showed a mosaic karyotype with 96% 63,XO and 4% 64,Xi(Y) cells. Molecular analysis of the isochromosome was carried out by fluorescence in situ hybridization and polymerase chain reaction with male-specific and pseudoautosomal markers from the horse Y chromosome. We found that the isochromosome was monocentric, composed of 2 long arms, carrying 2 sets of genes of the pseudoautosomal region (PAR) and the ma...
Correlation between jugular and central venous pressures in laterally recumbent horses. To compare and correlate right atrial pressure, which represents central venous pressure (CVP) to jugular vein pressure (JVP) in laterally recumbent horses under anesthesia. Methods: Retrospective clinical trial. Methods: Seven adult healthy horses (411 ± 8.7 kg). Methods: Horses were sedated with IV xylazine and anesthesia was obtained with IV ketamine and diazepam. Anesthesia was maintained with sevoflurane in oxygen. All horses were positioned in left lateral recumbency. An 8F catheter introducer was inserted into the right jugular vein to measure JVP. An 8F catheter introducer was i...
Hypoxic ischemic encephalopathy–what can we learn from humans? Hypoxic ischemic encephalopathy (HIE) is a condition that occurs in both human newborns and foals. The condition is the subject of extensive current research in human infants, but there have been no direct studies of HIE in foals, and hence, knowledge of the condition has been extrapolated from studies in humans and other animal models. The purpose of this review article is to highlight the most up-to-date and relevant research in the human field, and discuss how this potentially might have an impact in the management of foals with HIE.
Comparison of cortisol and ACTH responses after administration of thyrotropin releasing hormone in normal horses and those with pituitary pars intermedia dysfunction. Changes in both adrenocorticotropin (ACTH) and cortisol concentration in response to thyrotropin releasing hormone (TRH) administration have been used to diagnose equine pituitary pars intermedia dysfunction (PPID), but the use of the 2 hormones has not been compared. Objective: Measuring ACTH concentration is superior to measuring cortisol concentration after TRH administration in differentiating between normal horses and those with PPID, and the 2 hormone concentrations are disassociated in PPID horses. Methods: Eleven horses and 2 ponies with PPID and 19 normal horses. Methods: A study eval...
The relationship between serum calcium concentration and outcome in horses with renal failure presented to referral hospitals. Hypercalcemia is common in horses with renal failure, but it is not known whether it impacts prognosis. Objective: The primary objective of this study was to determine whether hypercalcemia was associated with decreased likelihood of survival to discharge in horses with renal failure. Secondary objectives were to determine whether hypercalcemia was more common in acute (ARF) or chronic renal failure (CRF), whether feeding alfalfa was associated with hypercalcemia, and whether serum creatinine concentration was associated with survival. Methods: Medical records of 63 horses presented to referra...
Genetic analysis of the Venezuelan Criollo horse. Various horse populations in the Americas have an origin in Spain; they are remnants of the first livestock introduced to the continent early in the colonial period (16th and 17th centuries). We evaluated genetic variability within the Venezuelan Criollo horse and its relationship with other horse breeds. We observed high levels of genetic diversity within the Criollo breed. Significant population differentiation was observed between all South American breeds. The Venezuelan Criollo horse showed high levels of genetic diversity, and from a conservation standpoint, there is no immediate danger ...
Hormone concentration changes temporally associated with the hour of transition from preluteolysis to luteolysis in mares. The temporal associations of cortisol, estradiol-17β, and oxytocin with pulses of PGFM at the common hour of transition between preluteolysis and luteolysis was studied in plasma from hourly blood samples in mares (n=8). The transitional hour was determined from progesterone concentrations and occurred between 2PM and 2AM in all mares. Pulses of PGFM were grouped into those occurring at the last pulse of preluteolysis (preluteolytic pulse), at the hour of transition (transitional), and during luteolysis (luteolytic). The preluteolytic PGFM pulse (45±16pg/ml at peak) and transitional pulse (4...
A comparison of antibody responses to commercial equine influenza vaccines following primary vaccination of Thoroughbred weanlings–a randomised blind study. Many racing authorities, sales companies and equestrian bodies have mandatory vaccination policies for equine influenza (EI). The consequences of lack of vaccine efficacy include clinical disease, disruption to training programmes, the cancellation of equestrian events and the introduction of virus to susceptible populations. The correlation between antibody against the virus haemagglutinin and protection against influenza has been well established. The objective of this study was to compare the antibody responses of 66 unvaccinated Thoroughbred weanlings on four different stud farms, followin...
Standing low-field magnetic resonance imaging appearance of normal collateral ligaments of the equine distal interphalangeal joint. High- and low-field magnetic resonance (MR) imaging systems are available for clinical diagnosis of collateral desmopathy of the equine distal interphalangeal joint (DIJ). Knowledge of the normal appearance, size, shape,and signal variation of these ligaments on high- and low-field MR images is essential when assessing desmopathy detected by MR imaging. However, there are no descriptions of the normal features of DIJ collateral ligaments on images obtained with a standing low-field MR system. Low-field MR imaging characteristics of normal collateral ligaments of the DIJ of cadaver feet were co...
Pathogen associated molecular pattern motifs from Gram-positive and Gram-negative bacteria induce different inflammatory mediator profiles in equine blood. Although the incidence of Gram-positive infection in horses is increasing, little is known about differences in inflammatory response between Gram-positive and Gram-negative organisms in this species. Equine blood was stimulated with components of both Gram-negative and Gram-positive organisms: lipopolysaccharide (LPS); lipoteichoic acid (LTA); peptidoglycan (PG); with combinations of LPS, LTA and PG; and with phosphate buffered saline (control). LPS, LTA and PG stimulated tumor necrosis factor (TNF) and interleukin (IL)-6 production but only LTA and PG stimulated IL-1β production from whole ...
Gene expression analysis in the thalamus and cerebrum of horses experimentally infected with West Nile virus. Gene expression associated with West Nile virus (WNV) infection was profiled in the central nervous system of horses. Pyrosequencing and library annotation was performed on pooled RNA from the CNS and lymphoid tissues on horses experimentally infected with WNV (vaccinated and naïve) and non-exposed controls. These sequences were used to create a custom microarray enriched for neurological and immunological sequences to quantitate gene expression in the thalamus and cerebrum of three experimentally infected groups of horses (naïve/WNV exposed, vaccinated/WNV exposed, and normal).From the sequ...
Determination of body water compartments in neonatal foals by use of indicator dilution techniques and multifrequency bioelectrical impedance analysis. To determine values for total body water (TBW), extracellular fluid volume (ECFV), intracellular fluid volume (ICFV), and plasma volume (PV) in healthy neonatal (< 24 hours old) foals and to create a multifrequency bioelectrical impedance analysis (MF-BIA) model for use in neonatal foals. Methods: 7 healthy neonatal foals. Methods: Deuterium oxide (0.4 g/kg, IV), sodium bromide (30 mg/kg, IV), and Evans blue dye (1 mg/kg, IV) were administered to each foal. Plasma samples were obtained following an equilibration period, and the TBW, ECFV, ICFV, and PV were calculated for each foal. An MF-BI...
The comparison of equine articular cartilage progenitor cells and bone marrow-derived stromal cells as potential cell sources for cartilage repair in the horse. A chondrocyte progenitor population isolated from the surface zone of articular cartilage presents a promising cell source for cell-based cartilage repair. In this study, equine articular cartilage progenitor cells (ACPCs) and equine bone marrow-derived stromal cells (BMSCs) were compared as potential cell sources for repair. Clonally derived BMSCs and ACPCs demonstrated expression of the cell fate selector gene, Notch-1, and the putative stem cell markers STRO-1, CD90 and CD166. Chondrogenic induction revealed positive labelling for collagen type II and aggrecan. Collagen type X was not detec...
Equine ELISPOT assay to study secretion of IFNγ and IL-4 from peripheral blood mononuclear cells. Human and mouse immune system cells are the most frequently used specimens in ELISPOT assays. In an effect to expand the application of ELISPOT assay to other species, we developed matched antibody pairs for ready-to-use kits designed for studying the frequency of equine IFNγ- and IL-4-secreting peripheral blood mononuclear cells (PBMCs). Equine PBMCs were stimulated with either concanavalin A (Con A) or calcium ionomycin mixed with phorbol 12-myristate 13-acetate (CaI + PMA). We found that Con A, in general, had a more profound stimulating effect than CaI + PMA on IL-4 secretion, whereas bot...
Flow cytometric detection of myeloperoxidase in horse neutrophils: a novel technique in equine diagnostic research. Myeloperoxidase (MPO) is a protein of interest due to its involvement in equine pathologies. Until now, results in equine diagnostic research were achieved through extracellular MPO detection. However, studying the cellular MPO content in neutrophils has revealed important insights in human diseases. This study aimed to develop a technique for the specific detection of MPO on the single cell level defining a flow cytometric protocol for the detection of both equine surface-bound and cellular MPO. Both indirect and direct labeling techniques are described which include the comparison of two sec...
In vitro characterization of EHV-4 gG-deleted mutant. Equine herpesvirus 4 (EHV-4) is an important pathogen that causes respiratory tract disease in horse populations worldwide. Glycoprotein G (gG) homologs have been identified in several alphaherpesviruses as minor non-essential membrane-anchored glycoproteins. In this study, EHV-4 gG deletion mutant has been generated by using bacterial artificial chromosome technology to investigate the role of gG in viral pathogenesis. Our findings reported here revealed no significant difference between parental EHV-4 and gG-negative strain in their replication cycle in cell culture. Furthermore, virus titer...
Genomic structure, polymorphism and expression of the horse alpha-actinin-3 gene. Gene characterization is an important feature for genome annotation and more particularly for candidate genes that could be selected in domestic species. Associations between an alpha-actinin-3 gene polymorphism and muscle performance were reported in humans involving a nonsense mutation (R577X) and in mice after inactivation of the gene. Here, we characterized the equine alpha-actinin-3 (ACTN3) gene by sequencing and transcript analysis. The cDNA was determined to be 3.47 kb in length with an open reading frame of 2709 bp expectedly encoding a protein 902 amino acids long. The ACTN3 gene is 1...
