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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.
Left ventricular volume determination in the horse by two-dimensional echocardiography: an in vitro study. This study was designed to evaluate the accuracy of two-dimensional echocardiography (2DE) in determining the left ventricular volume (LVV) of the horse in vitro. After examining the shape of the left ventricular silicon rubber casts of four equine hearts, two modified Simpson's rule methods (Model A and Model B) as combinations of conical shapes and one biplane area-length method as a single cone (Model C) were chosen for volume calculations. One long axis and three short axis planes were used for linear and area 2DE measurements, respectively. The ventricular length (L) was calculated from t...
Interspecies and interregional analysis of the comparative histologic thickness and laser Doppler blood flow measurements at five cutaneous sites in nine species. Studies in dermatology, cutaneous pharmacology, and toxicology utilize skin from different animal species and body sites. However, regional differences exist in topical chemical percutaneous absorption studies in man and in animal. The objective of this study was to compare epidermal thickness and number of cell layers across species and body sites using both formalin-fixed paraffin and frozen sections. Cutaneous blood flow determined by laser Doppler velocimetry (LDV) was compared to histologic data. Six animals of each of the following species were used: monkeys, pigs, dogs, cats, cows, hors...
Idiopathic granulomatous disease involving the skin in a horse. Clinical signs of generalized granulomatous disease in a horse included depression, generalized lymphadenopathy, scaly skin, and dependent edema. Diagnosis was confirmed histopathologically by diffuse granulomas in more than one organ system (lymph nodes and skin), and by ruling out etiologic agents. Response to treatment with corticosteroids was favorable. The clinical features and response to treatment in this horse were different from classic textbook descriptions of equine generalized granulomatous disease. Equine granulomatous disease appears to be comparable to human sarcoidosis. To avoi...
Intra-osseous pressure and pressure pulse gradients along the equine third metatarsal bone. Intra-osseous pressure measurements in the third metatarsal bone of anesthetised young and mature ponies demonstrated that a pressure gradient exists along the bone, the pressure being highest at the level of the nutrient foramen and decreasing distally and proximally from this point. The height of the intra-osseous pressure pulse also decreased toward the bone ends. It is concluded that the sites of measurement of the intra-osseous pressure in clinical and experimental studies should be standardized.
Measurement of endotoxic activity in feces of normal horses. Two chromogenic Limulus amebocyte lysate systems were evaluated for the measurement of endotoxic activity in feces of normal horses. Fecal extracts had neither non-specific nor inhibitory effect on the test reaction, and the two systems with different specificity showed equivalent results. Endotoxic activities in feces of healthy horses averaged 5.7 +/- 2.8 microns/g wet weight. Correlation between the endotoxin levels and the fecal microbial flora could not be determined.
Mast cells in normal and pathological specimens of the equine lung. In lungs from 22 horses, the number and type of mast cells in histologically normal specimens were compared with those in specimens with various histological lesions. Tissues fixed in Carnoy's solution were superior to those fixed in formalin for the identification of mast cells. Fixation of lung specimens from eight horses in Carnoy's solution and formalin allowed the identification of two subpopulations of mast cells: formalin-sensitive, which predominated and formalin-resistant. Specimens with mild chronic tracheitis and mild and moderate chronic bronchitis generally had slight increases in...
Effect of inositol hexakisphosphate on the spectroscopic properties of the nitric oxide derivative of ferrous horse and bovine hemoglobin. The effect of inositol hexakisphosphate (IHP) on the spectroscopic (EPR and absorbance) properties of the nitric oxide derivative of ferrous horse and bovine hemoglobin (Hb) has been investigated. In the absence of IHP, the nitric oxide derivative of ferrous horse Hb shows spectroscopic properties similar to those of the corresponding derivative of ferrous human Hb that are generally taken as typical of the high affinity state of tetrametric hemoproteins. Similar to human Hb, the addition of IHP to the nitric oxide derivative of ferrous horse Hb induces a transition toward a species characteri...
[The treatment basis for anticoagulants in horses]. The pharmacokinetics of racemic phenprocoumon were studied in 8 adult horses after the single intravenous and oral administration of 0.75 mg/kg. After i.v. administration the plasma concentration of phenprocoumon showed a biphasic decline in time. The pharmacokinetics were calculated on the two-compartment open model. The average plasma half-life (beta-phase) was 22 hours, the apparent volume of distribution was 0.61 l/kg, Cltot was 25.2 ml/kg/h (13.9-40.9 ml/kg/h). The systemic bioavailability of oral phenprocoumon was 97.6%, Tmax was found to be 4-12 hours. The effect of phenprocoumon on the...
Different combinations of regulatory elements may account for expression of the glycoprotein hormone alpha-subunit gene in primate and horse placenta. Expression of the glycoprotein hormone alpha-subunit gene occurs in the pituitaries of all mammals and in the placentas of primates and horses. In humans, tandem cAMP response elements (CREs), located in the proximal promoter-regulatory region of the alpha-subunit gene, act together with an adjacent upstream regulatory element to confer placenta-specific expression. Here, we report that the alpha-subunit genes of Old World Monkeys contain a single functional CRE. This suggests that tandem CREs are unique to higher primates and humans and are not absolutely required for placenta-specific expres...
Isolation and partial structural characterization of an equine fibrinogen CNBr fragment that exhibits immunologic cross-reactivity with an A alpha-chain cross-linking region of human fibrinogen. Immunochemical studies of equine fibrinogen were conducted to characterize the structural basis for the immunologic cross-reactivity observed between human and equine A alpha chains when employing an antiserum to the 26K, human cyanogen bromide (CNBr) fragment, A alpha 241-476 (CNBr VIII). A 38K, equine CNBr fragment that reacts with this antiserum was isolated from CNBr-digested equine fibrinogen by Sephadex G-100 gel filtration. It was further purified by sequential hydrophobic chromatography on phenyl-Sepharose CL-4B, followed by reversed-phased (C-8) high-performance liquid chromatography ...
Variable locations of nutrient foramina of the proximal phalanx in forelimbs of Thoroughbreds. Bilateral metacarpophalangeal radiographs of 100 Thoroughbreds were examined for visualization and location of the major nutrient foramen of the proximal phalanx. The foramina were located on the dorsal or palmar aspects of the cortex or were not visible radiographically. Of the 100 horses, 60 had the same pattern in both forefeet. In the remaining 40 horses, the left and right proximal phalangeal foramina were asymmetric. Of the 200 proximal phalangeal foramina (100 horses), 53 were on the dorsal aspect of the cortex and 101 were on the palmar aspect of the cortex; 46 were not visible radiogr...
Serum thromboxane generation by platelets in several domestic animal species. Blood collected from calves, sheep, goats, pigs, dogs, horses, ponies and donkeys, was allowed to clot under standard conditions. Thromboxane B2 generated during the clotting process was measured by radioimmunoassay in serum harvested from each sample. Highly significant differences were found between species and also between genera within a species. Highest concentrations of thromboxane B2 were detected in the dog samples (887.7 +/- 123.7 ng/ml) and lowest concentrations in samples from sheep (2.7 +/- 0.2 ng/ml). The amount of thromboxane produced per unit number of circulating platelets or p...
Tonometric and tonographic studies in the normal pony eye. Tonometric and tonographic techniques were evaluated in the normal pony and compared to other species. Applanation tonometry was utilised to calculate the ocular ridigity of the normal equine eye. The mean intraocular pressure for the pony eye was established as 23.5 mm Hg (sd +/- 4.5). Comparing the non-anaesthetised and anaesthetised pony eye (xylazine-ketamine and glycerol guaiacolate) no significant change in intraocular pressure occurred (P < 0.49). Mean aqueous outflow facility was 0.88 microliter/min/mm Hg (sd +/- 0.65) which is significantly higher (P < 0.01) than the canine and ...
The equine fundus. II: Normal anatomical variants and colobomata. A wide range of fundic variants are encountered during routine ophthalmoscopic examination of visually normal horses, often causing the examiner difficulty in assessing their clinical significance. Many of these are anatomical variants having no significant effect on visual function, and lie within the limits of normality in the horse. This paper illustrates this range of variants and discusses their anatomical basis and physiological consequences. Colobomata are non-progressive discontinuities in the structure of the anatomic fundus, occasionally noted as incidental findings during ophthalmos...
Immunodiffusion test for serodiagnosing subcutaneous zygomycosis. Culture filtrate antigens of Basidiobolus ranarum and Conidiobolus coronatus were analyzed by immunodiffusion (ID) with homologous rabbit antisera. B. ranarum and C. coronatus were each found to have five specific antigens. Results of tests with heterologous antisera indicated that all of the species shared at least one antigen. ID tests incorporating the specific precipitin bands as references were developed for detection of basidiobolomycosis and conidiobolomycosis. These tests were performed with sera from humans and horses with proven basidiobolomycosis and conidiobolomycosis as well as wi...
Synthesis of heat stress proteins in lymphocytes from livestock. Cultured bovine, equine, ovine and chicken lymphocytes responded to heat stress by the increased synthesis of a specific set of proteins known as heat stress proteins (HSP). Proteins with molecular weights of 70 and 90 kDa were synthesized in all species. Additional proteins were found in bovine, ovine and chicken lymphocytes. A time course of induction showed an increased synthesis of some of these proteins with only 30 min of heat stress and of several proteins with 60 min of heat stress. A specific monoclonal antibody was used to identify HSP70 as one of the stress proteins in bovine lympho...
A comparison of two computer-automated semen analysis instruments for the evaluation of sperm motion characteristics in the stallion. Two commercially available computer-automate semen analysis instruments (CellSoft Automated Semen Analyzer and HTM-2000 Motion Analyzer) were compared for their ability to report similar results based on the analysis of pre-recorded video tapes of extended, motile stallion semen. The determinations of the percentage of motile cells by these instruments were more similar than the comparisons between subjective estimates and either instrument. However, mean values obtained from the same sample may still differ by as much as 30 percentage units between instruments. Instruments varied with regard ...
Ultrastructural findings in horses with chronic obstructive pulmonary disease (COPD). I: Alterations of the larger conducting airways. Extensive light and electron microscope studies of the conducting airways were carried out in 28 horses with varying degrees of clinically manifested chronic obstructive pulmonary disease (COPD) and in 8 horses with normal lungs. The principal ultrastructural changes were found in the ciliated cells. There was focal loss of ciliated cells, which were replaced by undifferentiated cells in a largely hyperplastic epithelium, and some horses, independent of the degree of severity of the disease, showed various types of ciliary malformation. The finding of dilated intercellular clefts and accumulat...
Alteration of intestinal enzyme activities associated with extensive large-colon resection in horses. Lactase, maltase, sucrase, and alkaline phosphatase activities were determined in the intestinal mucosa from 3 locations in the small intestine and 4 locations in the large intestine 1 year after extensive large-colon resection (group 1; n = 5) and 1 year after sham operation (group 2; n = 3) in horses. Lactase, maltase, and sucrase activities were similar (P greater than 0.05) between group-1 and group-2 horses in all locations measured in the intestinal tract. Alkaline phosphatase activity in the remaining large colon of group-1 horses was significantly (P less than 0.05) greater than the ac...
Comparison of the adrenocortical response to both pharmacological and physiological stresses in sport horses. Seven sport horses were investigated to compare physiological and pharmacological stresses on the plasma glucocorticosteroid levels. Venous blood was sampled and analysed for cortisol concentrations before and after each type of stress. The physiological stress was induced by the completion of a cross-country and the pharmacological one, by an intravenous ACTH administration (200 micrograms) in the same horses, one week after the course. Both exercise and ACTH injection induced a highly significant cortisol increase of 79 +/- 0.10% and 160 +/- 0.18%, respectively. The relative plasma cortisol ...
Arytenoidectomy for advanced unilateral chondropathy with accompanying lesions. A noncurrent prospective study of nonworking horses with arytenoid chondropathy was conducted to confirm a clinical impression that horses with unilateral chondropathy and accompanying lesions had a poorer prognosis after arytenoidectomy than horses with bilateral or uncomplicated unilateral chondropathy. Surgical failure was defined as death, euthanasia, permanent tracheostomy, or reoperation. Survival to surgical failure and clinical improvement data were compared between horses with and without accompanying lesions treated by arytenoidectomy. The probability of surgical failure was signific...
Peritoneal fluid values from healthy foals. Peritoneal fluid was analysed from 17 foals, aged 13 to 134 days with a mean age of 68 days. Cytologically, the peritoneal fluid was characterised by a mean total cell count of 0.45 x 10(9)/litre (range 0.06 to 1.42 x 10(9)/litre), rare eosinophils, rare cytophagia and variable percentages of neutrophils and mononuclear cells. These data indicate that peritoneal fluid nucleated cell counts over 1.50 x 10(9)/litre in the foal should be interpreted as elevated. Biochemical evaluation revealed a mean biuret protein level of 12 g/litre, mean refractive index protein level of 16 g/litre and urea ni...
Source of oestrogen in early pregnancy in the mare. Oestrogen secretion was determined by oestrogen conjugate (EC) analysis of urine in three groups of pregnant mares: Group I (N = 6), animals ovariectomized on Day 18-19 of gestation with pregnancy maintained by daily administration of an oral progestagen, altrenogest; Group II (N = 9), untreated, pregnant mares; Group III (N = 5) intact, pregnant mares treated daily with altrenogest. The mean EC concentrations in the ovariectomized mares in Group I increased in a constant linear manner from 17 ng/mg Cr on Day 20 to 291 ng/mg Cr on Day 70, with no apparent surge in oestrogen secretion around Da...
Follow-up report of a case of surgical aphakia with an analysis of equine visual function. More work is necessary to establish corneal dimensions and retinal structure and neural organisation in the equine eye. This paper reports a case of surgical management of bilateral cataracts in a pony and the results of a survey of refractive error in normal horses. Aspects of accommodation are discussed. It is suggested that a difference in retinal receptor organisation between horse and human eyes could explain the good visual performance of the aphakic pony; and that the degree of blurring of vision in the aphakic situation is less, both in absolute terms and in proportion to presumed norm...
The morphology of the equine iridocorneal angle: a light and scanning electron microscopic study. The present investigation of 20 equine eyes shows that the iridocorneal angle of the horse is characterised by a very distinct pectinate ligament and a large ciliary cleft. The pectinate ligament consists of long and broad pigmented trabeculae which form a firm, flat and dense network that encircles the eye. On meridional sections, the ciliary cleft is visible as a wide triangular space comprising the trabecular meshwork which consists of two parts. The inner part is the larger and forms a three-dimensional network of large pigmented trabeculae with very wide intertrabecular spaces. The outer ...
Analysis of peritoneal fluid as a diagnostic aid in grass sickness (equine dysautonomia). The analysis of peritoneal fluid is of value in the differential diagnosis of equine colic but its characteristics have not been evaluated in grass sickness. Peritoneal fluid was collected from 15 normal horses and from 11 cases of medical colic, 11 cases of surgical colic, 20 cases of acute grass sickness and 13 cases of subacute grass sickness. The fluid was analysed for its appearance, total and differential white cell count, specific gravity, total protein concentration and total and intestinal alkaline phosphatase activity. Fluid from cases of medical colic was normal in these respects. S...
Histochemical profile of articularis humeri muscle in the horse. In this study the histochemical fiber type analysis of the articularis humeri muscle of the horse was performed. This muscle is composed of type I and type IIA fibers. A large number of spindles has been observed and the presence of these receptors could help to understand the role played by this muscle.
Evaluation of high performance liquid chromatography (HPLC), enzyme linked immunosorbent assay (ELISA) and particle concentration fluorescence immunoassay (PCFIA) methods for the screening, quantitation and pharmacokinetic study of furosemide in horses. Equine plasma and urine samples were analyzed by using a high-performance liquid chromatography (HPLC), enzyme-linked immunosorbent assay (ELISA) and particle concentration fluorescence assay (PCFIA). Although ELISA and PCFIA were rapid, simple and sensitive for the screening of furosemide, they did not give reproducible quantitative results. The HPLC method, which required relatively longer analysis time, provided simple and reproducible quantitative analysis of furosemide in plasma and urine. The performance of the three methods was compared for the quantitation of furosemide in plasma obtai...
