Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
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 exclusive use of ivermectin vs alternation of antiparasitic compounds for control of internal parasites of horses. A study for about a 30-month period was done to compare strongyle control programs, using per os treatments of ivermectin (IVE) paste exclusively or alternation of 4 antiparasitic paste compounds: IVE, oxfendazole (OFZ), oxibendazole (OBZ), or pyrantel pamoate (PRT). Every 8 weeks, 1 group of horses (barn C; n = 14 to 16) was given IVE paste exclusively, and a second group (barn E; n = 16) was given the 4 antiparasitic pastes on an alternating schedule. Worm eggs and larvae per gram of feces (epg and lpg, respectively) values were determined every 2 weeks during the investigation. This study i...
Bone biopsy in the horse. 2. Evaluation of histomorphometric examination. The histomorphometrical examination of a series of bone biopsies from the wing of ilium of foals and older horses is reported. Biopsies were obtained from 20 clinically normal horses, which had previously been infused with tetracycline intravenously twice at a 7 day interval at a dose rate of 10 to 15 mg kg-1. The horses were divided into 2 groups. Group 1 consisted of 10 foals (mean age: 4 +/- 1 months) which were biopsied at 3 different sites in the wing of ilium. Group 2 comprised 10 older horses (mean age: 91 +/- 63 months) which were biopsied from only one site in the left ilium. A system...
Respiratory muscle recruitment in awake ponies during exercise and CO2 inhalation. We measured respiratory muscle electromyograms (EMG), inspiratory (I) and expiratory (E) airflow patterns and functional residual capacity (FRC) in six ponies at rest, during treadmill walking at 1.8 mph-5, 10, and 15% grades, and during 2, 4, and 6% CO2 inhalation. There were several similarities in the responses to exercise and CO2 inhalation. The shapes of the I and E flow patterns were not changed appreciably from the respective control patterns during either condition. Mean diaphragm EMG increased from control (P less than 0.05) at 1.8 mph-10 and 15% grades, and during 4 and 6% inhalation...
An estimate of melanosome concentration in pigment tissues. Concentration of melanosomes in various tissues has been unknown because of the impracticability of their direct quantification. Using an indirect approach comprising the estimation of melanin both in freeze-dried tissue samples and in isolated melanosomes, we obtained data on the amount of melanosomes in various pigment tissues. The concentrations of melanosomes found in the tissues were relatively high, not only reflecting the dark color of pigment tissues but also explaining their capacity to perform various functions ascribed to the presence of melanin.
Bone biopsy in the horse. 3. Normal histomorphometric data according to age and sex. Histomorphometrical analysis of bone biopsies from the wing of ilium in 35 clinically normal horses are reported according to age. The biopsies were collected from 20 mixed-bred foals (mean age 6 +/- 1 months) and 15 older horses (mean age 73 +/- 62 months). No gender differences were found in the group of foals examined, but a significant difference (p less than 0.001) in a number of the primary measurements occurred between them and the older horses. The parameters which altered with age were the extent of osteoid surface (OS/BS), the extent of resorption (erosion) surface (ES/BS), the osteo...
Comparison of high-performance liquid chromatography with a radiometric assay for determination of the effect of intra-articular administration of corticosteroid and saline solution on synovial fluid hyaluronate concentration in horses. Two recently developed direct methods, radioassay-125I-labeled hyaluronic acid binding protein (125I-HABP)- and high-performance liquid chromatography (HPLC), were used to assess and compare the concentration of hyaluronate (HA) in synovial fluid of horses. Also determined were changes in the HA concentration in an experimental treatment model involving physiologic saline solution (PSS)-irrigated or methylprednisolone acetate-injected tarsocrural joints of clinically normal horses. Serum HA concentration was determined simultaneously, using the 125I-HABP assay. Synovial fluid HA concentration ...
Rhodococcus equi plasmids: isolation and partial characterization. Fifty-four strains of Rhodococcus equi from different clinical sources (mainly horses and pigs) were examined for their plasmid content by two screening methods. Plasmids were detected in 49 of 54 strains. A plasmid of approximately 80 kb was isolated from 21 of 22 isolates from horses and 20 of 28 isolates from pigs, and a 105-kb plasmid was isolated from 7 of 28 isolates from pigs. The 80-kb plasmid was significantly associated with strains of equine rather than porcine origin, and the 105-kb plasmid was significantly associated with strains of porcine origin. The type strain, ATCC 6939, con...
Comparison of clinical chemical variables in blood plasma and serum of horses. Several clinical chemical blood variables were compared, in order to evaluate the differences between Na heparinized plasma and serum samples. Samples from 45 healthy horses were used. No differences between the two sample substrates were found for aspartate aminotransferase, lactate dehydrogenase, lactate dehydrogenase-isoenzymes, creatine kinase, alkaline phosphatase, bilirubin, cholesterol, urea, total protein, alpha-globulin, gamma-globulin, albumin, calcium (Ca), phosphate (P), sodium (Na) and potassium (K). gamma-Glutamyltransferase and beta-globulin were significantly higher in heparini...
Purification and kinetic characterization of equine infectious anemia virus reverse transcriptase. The reverse transcriptase of Equine Infectious Anemia Virus (EIAV) was partially purified from virus particles and appeared to be a heterodimer with subunit molecular masses of 70 kdal and 59 kdal. The polymerase activity of this enzyme had an absolute requirement for a divalent cation, preferring Mg++ over Mn++. Addition of a monovalent cation to the reaction mixture enhanced, but was not required for enzyme activity. Kinetically, the reverse transcriptase of EIAV is similar to the reverse transcriptase of Human Imunodeficiency Virus Type 1 (HIV-1). Both enzymes have similar Km values for 2'-...
Comparison of the sedative effects of medetomidine and xylazine in horses. The sedative effects in horses of the new alpha 2 agonist medetomidine were compared with those of xylazine. Four ponies and one horse were treated on separate occasions with two doses of medetomidine (5 micrograms/kg bodyweight and 10 micrograms/kg bodyweight) and with one dose of xylazine (1 mg/kg bodyweight) given by intravenous injection. Medetomidine at 10 micrograms/kg was similar to 1 mg/kg xylazine in its sedative effect but produced more severe and more prolonged ataxia, and one animal fell over during the study. Medetomidine at 5 micrograms/kg produced less sedation but a similar deg...
Structure of equine corticotropin releasing factor. A 41 amino acid peptide, probably identical in structure to human corticotropin releasing factor, was isolated from 70 equine hypothalami by methanol extraction, immunoaffinity chromatography and single step of reverse phase HPLC. The amino acid sequence was determined by gas phase sequence analysis. Probable carboxyl terminal amidation was demonstrated by similar retention times for equine and human corticotropin releasing factor on reverse phase HPLC at pH 8. The likely structure of equine corticotropin releasing factor is: Ser-Glu-Glu-Pro-Pro- Ile-Ser-Leu-Asp-Leu-Thr-Phe-His-Leu-Leu-Arg-Glu...
Bronchoalveolar lavage findings in horses with exercise intolerance. Significant differences were detected by bronchoalveolar lavage (BAL) between horses racing successfully and those showing exercise intolerance. Neutrophil percentage, haemosiderophage percentage and total bacterial numbers were significantly elevated in horses with exercise intolerance. BAL provided a more accurate indication of the incidence and extent of exercise induced pulmonary haemorrhage (EIPH) than visual inspection.
Measurement of oxytocin concentrations in plasma and ovarian extracts during the oestrous cycle of mares. Jugular venous blood samples were collected throughout a complete oestrous cycle from 9 mares for measurement of progesterone and oxytocin by radioimmunoassay. Mean oxytocin concentrations remained at approximately 1 pg/ml throughout, with no evidence of cyclic variation in the release pattern. Extracts of corpus luteum and follicles obtained from a further 33 mares at different stages of the cycle all contained oxytocin concentrations of less than 10 pg/g wet weight of tissue. We conclude that the ovaries are not a source of circulating oxytocin during the oestrous cycle in this species. The ...
Plasma histamine levels in laminitic horses and in horses treated with a corticosteroid. In seven sound horses histamine plasma levels were evaluated by means of a radioenzymatic method using the enzyme histamine-N-methyltransferase (mean = 4.46 nmol/l, SD = 1.55 nmol/l). Histamine levels of laminitic horses were significantly higher (n = 11; mean = 12.46 nmol/l, SD = 3.24 nmol/l). In three sound horses plasma histamine levels were determined over a two week period following a double administration of 10 mg dexamethasone-21-isonicotinate/100 kg body weight. Histamine levels remained within the range of sound control horses.
Electromagnetic stimulation of bone repair: a histomorphometric study. The effect of pulsing electromagnetic fields (PEMFs) on bone repair was studied in principal metacarpal bones of eight adult male horses: Six horses were treated with PEMFs, and two horses were untreated. In treated horses, Helmholtz coils were applied during a 60-day period to the left metacarpal bones, bored with eight holes of equal diameter and depth, from the middiaphysis toward the distal metaphysis. Eight equal holes bored in the right metacarpal, surrounded by unactivated Helmholtz coils, were taken as controls. The two untreated horses were taken as additional control. The results of ...
Thermodilution estimation of cardiac output at high flows in anesthetized horses. The purpose of this study was to compare the thermodilution technique for estimation of cardiac output with the indocyanine green dye dilution technique at flows between 10 and 39 L/min in halothane-anesthetized horses. The estimation of area of dye dilution cardiac output curves was made by using the fore-'n-aft (FA) triangle method. This shorthand technique was compared with logarithmic exponential extrapolation and summation (extrapolated area), using 64 cardiac output curves. Then, 256 simultaneous thermodilution measurements were compared with dye dilution measurements calculated by use o...
Stability of equine lysozyme. I. Thermal unfolding behaviour. The thermal denaturation of Ca(2+)- and apo-forms of equine lysozyme was followed by using far and near UV circular dichroism and intrinsic fluorescence methods. The difference found between the temperature dependence of the ellipticity at 222 nm and 287 nm, which show two stages in the thermal transition, and those at 228 nm and 294 nm, which indicate only one stage over a wide range of temperatures reflects that different subdivisions of the protein molecule are characterized by a different stability, cooperativity and pathway of denaturation. The first transition, reflected in the increase ...
Actinobacillus spp. and related bacteria in infected wounds of humans bitten by horses and sheep. We describe the isolation of Actinobacillus lignieresii and an A. equuli-like bacterium from an infected horse-bite wound in a 22-year-old stable foreman and A. suis from a bite injury in a 35-year-old man who had been attacked by a horse. A. lignieresii was also isolated in pure culture from an infected sheep-bite wound in a rural worker. These species of the genus Actinobacillus are primarily associated with animals and animal diseases and are rarely isolated from humans. The purpose of this report is to raise awareness of the possible occurrence of Actinobacillus spp. in bite wounds inflict...
The body condition of feral ponies on Assateague Island. The summer body condition of 47 adult feral ponies on Assateague Island (off the coast of Maryland, USA) was assessed in June 1988 using a visual body condition scoring system. Winter body condition for 36 of the ponies was assessed in February and March, 1989. The ponies were categorised by gender, reproductive status and location on the island, and body condition scores of the ponies in each category were then compared by statistical analyses. No significant seasonal differences were found in the body conditions of the ponies. However, body condition of stallions was better than that of mare...
Influence of age on neutrophil function in foals. Functional activities (phagocytosis and killing) of neutrophil leucocytes (NL) and immunoglobulin G concentrations were evaluated in six healthy foals from birth to 6 months of age. Peripheral blood NL were reacted with Streptococcus equisimilis in 20 per cent pooled equine serum for 30, 60 and 90 mins and functional activities of NL were determined using a fluorochrome microassay. Values for foal NL function were compared with those of healthy adult horses (n = 28). Foal neutrophil function was influenced by age. Killing capacity of NL decreased, whereas phagocytic capacity increased, until 1...
The isolated perfused equine skin flap. Preparation and metabolic parameters. A model for the study of equine cutaneous physiology, pharmacology, and toxicology was developed. Four 4 x 12 cm and twenty-one 6 x 12 cm single-pedicle axial pattern skin flaps based on the caudal superficial epigastric artery, and eight 6 x 12 cm flaps based on the saphenous artery and medial saphenous vein, were raised and sutured in a tubed configuration. On day 2, each flap was removed, the artery was cannulated, and the flap was perfused with a modified Krebs-Ringer's albumin-based medium for at least 6 hours. Flap viability was assessed by glucose use, lactate production, and histologic...
Coprophagy in animals: a review. Coprophagy is performed by rodents and lagomorphs and to a lesser degree by piglets, foals, dogs and nonhuman primates. Due to the construction of the digestive system of rodents and rabbits, coprophagy is necessary to supply many essential nutrients. Bacterial synthesis of nutrients occurs in the lower gastrointestinal tract in these animals where little absorption is realized. The eating of their feces provides a method for obtaining these nutrients.
Relationships between lymphoid nodules and lymph sinuses in lymph nodes: a study in horses. Secondary lymphoid nodules in lymph nodes of the horse are surrounded by a network of lymph sinuses, including the subcapsular sinus and its extensions around tabeculae, tubular and tubule-like sinuses deeper in the cortex, and sinuses between cord-like projections of cortical tissue. The precise role of this close association between sinuses and nodules in the transport of immune complexes, cells and cytokines is not known.
Horse and marmoset monkey sperm bind to the zona pellucida of salt-stored human oocytes. The present study demonstrates that horse and marmoset monkey sperm can bind to the human zona of salt-stored oocytes that failed to fertilize in vitro. Marmoset monkey sperm are also able to penetrate the salt-stored human zona. In contrast, human sperm do not bind to the zona of either horse or marmoset monkey oocytes. These results suggest that human sperm binding to the zona pellucida is more strictly species-specific than it is for horse and marmoset monkey sperm. In contrast, horse and marmoset monkey sperm contain receptors recognized by the human zona.
Use of scintigraphy for the determination of mucociliary clearance rates in normal, sedated, diseased and exercised horses. Mucociliary clearance rates from the trachea were determined in normal, sedated, diseased and exercised horses from scintigraphs obtained after an injection of technetium-99m sulphide colloid into the tracheal lumen. The group mean tracheal clearance rate of eight clinically normal horses during 42 trials was 2.06 +/- 0.38 cm/min. Significant between horse differences were found (p less than 0.05). When six and seven of these horses were given xylazine and detomidine hydrochloride, respectively, mean group tracheal clearance rates dropped significantly (p less than 0.05). The decreases from ea...
The equine major plasma serpin multigene family: partial characterization including sequence of the reactive-site regions. The equine Pi system, which is highly polymorphic and was considered to be controlled by a single locus, has been shown to be controlled by four loci (named Spi 1-4). This system is the equine equivalent of the major human plasma serpin (serine protease inhibitor), human alpha 1 PI. Twenty-two haplotypes of the equine Pi system have been characterized by two-dimensional electrophoresis, resulting in the assignment of pI, Mr, and bovine trypsin and chymotrypsin inhibition characteristics to 109 proteins. These proteins have been analyzed further to determine their relatedness to each other as w...
[Monitoring of the oxygen saturation of horses during halothane anesthesia using pulse oximetry in the nasal septum]. The use of pulse oximetry for on-line monitoring of oxygen saturation of arterial blood using a probe on the nasal septum is described in the horse. When compared to the results of blood gas analysis an excellent correlation between the two methods for measuring oxygen saturation is found. Nevertheless a discrepancy between the values for oxygen saturation provided by either method is found. This can lead to misinterpretation of oxygen saturation values generated by the pulse oximeter. The cause of this discrepancy is not clear but differences in measuring principle, presence of dyshemoglobins...
Use of nonimaging nuclear medicine techniques to assess the effect of flunixin meglumine on effective renal plasma flow and effective renal blood flow in healthy horses. The effect of flunixin meglumine on renal function was studied in 6 healthy horses by use of nonimaging nuclear medicine techniques. Effective renal plasma flow (ERPF) and effective renal blood flow (ERBF) were determined by plasma clearance of 131I-orthoiodohippuric acid before and after administration of flunixin meglumine. Mean ERPF and ERBF was 6.03 ml/min/kg and 10.7 ml/min/kg, respectively, before treatment and was 5.7 ml/min/kg and 9.7 ml/min/kg, respectively, after treatment. Although ERPF and ERBF decreased after flunixin meglumine administration, the difference was not statistically ...
Identification and comparative sequence analysis of a gene in equine herpesvirus 1 with homology to the herpes simplex virus glycoprotein D gene. A homologue of the herpes simplex virus (HSV) glycoprotein D gene has been identified in the genome of equine herpesvirus-1 (EHV-1, equine abortion virus). An open reading frame in the middle of the short unique (US) region is capable of encoding a polypeptide of 402 amino acids that has 26% and 20% of its residues matching pseudorabies virus (PRV) gp50 and HSV-1 gD, respectively. Despite this low level of similarity, the positional identity of six cysteine residues and certain motifs, and the location of the EHV-1 gene, clearly define the EHV-1 polypeptide as one of a family of "gD-like" prot...
[Taylorella equigenitalis: cell wall proteins, gene fingerprints, plasmids, adhesion and toxicity]. In this study 55 strains of Taylorella equigenitalis isolated from horses of four different studs in Austria, and a comparative strain from the Federal Republic of Germany were investigated by different methods. These investigations were carried out with the help of SDS-PAGE, immunoblotting, the analyses of genomes and by proof of plasmids. Furthermore, pathogenic mechanisms such as adhesion or the formation of toxins were investigated in vitro. On the basis of the results carried out by means of SDS-PAGE and immunoblotting all tested strains of Taylorella equigenitalis were alike, whereas by ...
