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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.
Immunocytochemical localization of luteinizing hormone and follicle-stimulating hormone in the equine pituitary. Gonadotropin-specific primary antisera and gold-conjugated secondary antibodies were used to immunocytochemically localize gonadotropins in the anterior pituitary of intact pony mares. Electron microscopy was then used to characterize the ultrastructure and immunoreactive staining characteristics of equine gonadotropes. Cells containing LH were morphologically indistinguishable from those containing FSH. Gonadotropes were relatively large and commonly had eccentric nuclei. The rough endoplasmic reticulum was well developed and dilated. Secretory granules were present in two morphologically dis...
Environmental control to maintain stabled COPD horses in clinical remission: effects on pulmonary function. The objective of this study was to test the hypothesis that stabled COPD horses can be maintained in clinical remission by replacing hay by grass silage and bedding made of wood shavings (Period B) and of wheat straw (Period C) during 6 weeks, respectively. At the end of these different periods, the pulmonary function of the horses was assessed by mechanics of breathing and arterial blood analyses. These results were compared to those measured in clinical remission obtained after 2 months in pasture (Period A). No significant difference was observed between these 3 periods neither to values ob...
[Determination of fibrinogen levels in the horse with the heat-precipitation methods of Schalm and Millar]. The purpose of this study was to investigate the usefulness of two heat-precipitation techniques (Schalm- and Millar-method) as screening tests to measure plasma fibrinogen concentration in horses. Based on the measurement of samples from 108 different horses, the coefficient of correlation (CC) for the relationship between the results with the Schalm- and with the reference-method (Jacobsson) were much lower (r = 0.78) than between the Millar- and Jacobsson-method (r = 0.94). Furthermore the Schalm-method was less precise as reflected by the greater coefficient of variation (CV, within-run pr...
[Histologic studies on the corpora amylacea in the mammary glands of goats, horses, and ewes]. Corpora amylacea are present in all the mammary glands of the investigated animals (ewe, goat, and mares). Generally, they are comparable to the cow regarding to its distribution, frequency, size, morphological structure, and staining properties. Corpora amylacea occur most frequently in the ewe, and in non-lactating mammary glands. In lactating mammary glands they are mostly situated in the alveoles. During gestation they are located outside of the alveoles and in the interalveolar connective tissue. Only in very few cases corpora amylacea are found inside and outside of the alveoles in the s...
Carcinoma in situ and seminoma in equine testis. The presence of atypical germ cells resembling carcinoma in situ of human testis is reported for the first time in an unilaterally cryptorchid stallion. These cells were found in association with developing intratubular seminoma indicating they represented carcinoma in situ.
Nucleotide sequences of glycoprotein I and E genes of equine herpesvirus type 4. The nucleotide sequences of the glycoprotein I (gI) and E (gE) genes of equine herpesvirus type 4 (EHV-4) strain TH20 were determined. The predicted region encoding the EHV-4 gI gene is 1,263 nucleotides, corresponding to a polypeptide of 420 amino acids in length. The predicted region encoding the EHV-4 gE gene is 1,647 nucleotides, corresponding to a polypeptide of 548 amino acids in length. The EHV-4 gI and gE genes show 74% and 85% identity at the amino acid level with those of equine herpesvirus type 1 (EHV-1), respectively. Furthermore, we have found an open reading frame homologous to t...
In vitro pullout strength of screws inserted in adult equine third metacarpal bone after overdrilling a 4.5-mm threaded insertion hole. To determine and compare the in vitro pullout strength of 5.5-mm cortical versus 6.5-mm cancellous bone screws inserted in the diaphysis and metaphysis of adult equine third metacarpal (MCIII) bones, in threaded 4.5-mm cortical bone screw insertion holes that were then overdrilled with a 4.5-mm drill bit to provide information relevant to the selection of a replacement screw if a 4.5-mm cortical screw is stripped. Methods: In vitro pullout tests of 5.5-mm cortical and 6.5-mm cancellous screws in equine MCIII bones. Methods: Two independent cadaver studies each consisting of 14 adult equine MCI...
Effects of experimental desmotomy on material properties and histomorphologic and ultrasonographic features of the accessory ligament of the deep digital flexor tendon in clinically normal horses. To evaluate posttrauma biomechanical behavior of the scar attributable to desmotomy of the accessory ligament of the deep digital flexor tendon (AL-DDFT), compared with the histomorphologic and ultrasonographic appearance. Methods: 5 Standardbred trotters. Methods: Gross appearance, length, cross-sectional area (CSA), in vitro material properties, and ultrasonographic and histomorphologic features were studied 6 months after desmotomy. Tensile tests were conducted, with forces and elongation simultaneously recorded. Surgically treated limbs were compared with nontreated contralateral limbs. Re...
Pharmacokinetics of ketoprofen in healthy foals less than twenty-four hours old. To determine pharmacokinetic variables that describe disposition of ketoprofen after its i.v. administration to foals < 24 hours old. Methods: 6 healthy foals (1 male and 5 females); mean age, 12.5 (range, 8.5 to 17) hours at time of dose administration. Methods: Ketoprofen was administered i.v. to foals at a dosage of 2.2 mg/kg of body weight. Ketoprofen concentration in plasma samples was analyzed, using high-performance liquid chromatography. Concentration versus time profiles were analyzed according to standard pharmacokinetic techniques. Blood samples were obtained from foals by jugula...
[Radiotherapy in veterinary medicine (review)]. A review of the latest literature concerning the present level of radiation therapy in veterinary medicine is given. In a general section physico-technical as well as biological fundamentals are discussed. In the special part of the paper indications for a radiation therapy of dogs, cats and horses are stated. In this respect the basis for a decision is the TNM-classification into different clinical stages according to the directions of the WHO. Tumors of the hemolymphatic system are very responsive to radiation therapy. While epithelial tumors are sensitive, tumors arising from the mesenchyma...
Comparative immunohistochemical study of stellate cells in normal canine and equine adenohypophyses and in pituitary tumours. The presence and distribution of S100 protein (alpha and beta subunits), cytokeratin polypeptides, glial fibrillary acidic protein, neurofilaments, vimentin, neuron specific enolase, synaptophysin, HLA class II DR antigen, and pituitary hormones (prolactin, adrenocorticotropic hormone and human chorionic gonadotrophin) in stellate cells were studied immunohistochemically in four normal canine pituitary glands, five canine pituitary adenomas, two canine pituitary carcinomas and two equine pituitary adenomas (with surrounding normal glandular tissue). Stellate cells of the pars distalis and pars...
A case-crossover study of intensive racing and training schedules and risk of catastrophic musculoskeletal injury and lay-up in California thoroughbred racehorses. The objective of this study was to investigate the relationship between intensive racing and training schedules and risk of either catastrophic musculoskeletal injury (CMI) or lay-up from racing in California Thoroughbreds. Thoroughbred racehorses that sustained a CMI during racing or training and either were subsequently euthanized or died on a California racetrack during 1991 and 1992 were studied using a case-crossover study design. Each study subject (case) provided its own self-matched control information in the form of 'typical' exposure frequency, determined or estimated from historic i...
Inhibition and inactivation of equine aromatase by steroidal and non-steroidal compounds. A comparison with human aromatase inhibition. In order to approach the detailed structure-function relationships of aromatase, we studied the inhibitory and inactivatory potencies of several steroidal androstenedione analogues (1: 4-hydroxyandrostenedione, 2: 4-acetoxyandrostenedione and 3: 7 alpha-(4'-amino)phenylthio-4-androstene-3, 17-dione) and non-steroidal imidazole derivatives (4: ketoconazole, 5: miconazole and 6: fadrozole) on equine aromatase in placental microsomes, a well established mammalian model. Human placental microsomes and the purified enzyme from equine testis were also used to compare inhibition by 1 and 2. In equine...
Is the thoroughbred race-horse under chronic stress? Thoroughbred fillies were divided into three groups according to age: group 1, 7 fillies aged 1 to 2 years (G1) starting the training program; group 2, 9 fillies aged 2 to 3 years (G2) in a full training program; group 3, 8 older fillies 3 to 4 years of age (G3) training and racing. Blood samples were collected weekly from July to December. Cortisol was quantified using a solid phase DPC kit. The intra- and interassay coefficients of variation were 12.5% and 15.65% and sensitivity was 1.9 +/- 0.2 nmol/l. The semester average of cortisol levels varied between groups: G1 = 148.8 +/- 6.7, G2 = 12...
Reliability of coprological diagnosis of Anoplocephala perfoliata infection. Three coprological methods were tested to establish the reliability of in vivo diagnosis of Anoplocephala perfoliata. A total of 107 faecal samples were analyzed, and the presence of tapeworms were confirmed postmortem in 24 animals with burdens that ranged from 1 to 248 worms; most of them (71%) with less than 100 parasites. Best results were obtained with a combination of two sedimentation/flotation methods, detecting only half the parasitized animals (54% sensitivity). No relationship could be established between tapeworm burden and egg detection, but results indicate that coprological meth...
Screening for bovine papillomavirus in peripheral blood cells of donkeys with and without sarcoids. Papillomaviral DNA has been identified in peripheral blood cells of both cattle and humans with and without associated disease and it has been suggested that such cells may act as sites of viral latency. In order to investigate the possibility of latent papillomaviral infection in the aetiopathogenesis of the equine sarcoid, peripheral blood derived DNA samples from 20 healthy and 34 sarcoid-affected donkeys were subject to polymerase chain reaction (PCR) using papillomaviral specific primers. Analysis of blood derived DNA samples failed to demonstrate the presence of papillomaviral DNA in any...
Equus caballus gelsolin–cDNA sequence and protein structural implications. We have generated and characterized the cDNA from equine smooth muscle that encodes gelsolin, an actin-modulating protein. Overlapping cDNA clones synthesized by the reverse transcriptase/polymerase chain reaction and clones isolated from a horse genomic library provided the complete primary structure for the intracellular isoform of gelsolin, while cDNA complemented with protein sequence data produced the full-length primary transcript of the gelsolin isoform found circulating in equine plasma. The deduced amino acid sequences of the intracellular and secreted versions of equine gelsolin infe...
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...
