Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Physiology
The physiology of horses encompasses the study of the biological functions and processes that occur within the equine body. This includes the examination of various systems such as the cardiovascular, respiratory, musculoskeletal, digestive, and nervous systems. Understanding equine physiology is essential for comprehending how horses adapt to different environmental conditions, perform physical activities, and respond to health challenges. Research in this field often focuses on the mechanisms of energy metabolism, thermoregulation, and muscle function during exercise, as well as the physiological responses to stress and disease. This page compiles peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine physiology, providing insights into the biological processes that support the health and performance of horses.
Neuromuscular blocking agents in equine anesthesia. In summary, neuromuscular blocking agents can be used safely and to advantage in equine anesthesia. Muscle-relaxant use in equine anesthesia has been helped by the development of new relaxants such as atracurium, which has a reliable and reproducible duration of action. There are certain cases that benefit particularly by the use of relaxants but their use is not limited to these cases. These cases involve horses that experience persistent movement and hypotension during anesthesia, are undergoing ophthalmic or abdominal surgery or fracture repair, or are severely ill. Horses receiving muscle ...
Crystallization and properties of creatine kinase from equine skeletal muscle. A crystalline creatine kinase was obtained from equine skeletal muscle. The enzyme was homogeneous, as judged by ultracentrifugation and disc electrophoresis on polyacrylamide gel. The crystalline enzyme had a specific activity of 110 units per mg of protein, that is, 14-fold purification over the crude extract of equine skeletal muscle. The molecular weight of the enzyme was determined to be 84,600 by the conventional low-speed sedimentation equilibrium method, and s020,w was 5.32S. Eight cysteine residues were found on amino acid analysis, two of which were essential for the enzymatic activi...
Pharmacokinetics and behavioral effects of methylphenidate in Thoroughbred horses. In horses given (rapid IV) methylphenidate (Ritalin, alpha-phenyl-2-piperidinacetic acid methyl ester; 0.70 mg/kg), plasma concentrations of the drug decreased rapidly at first, with an apparent alpha half-life of about 19 minutes, and then more slowly, with an apparent beta half-life of about 2.4 hours. These data were well fitted by a 2-compartment open model. In blood, about 40% of the methylphenidate present was in the plasma fraction, and of this, about 80% was plasma-protein bound. If given by subcutaneous or IM injection, plasma concentrations of methylphenidate peaked in about 1 hour a...
Solubility of halothane in equine tissues at 37 degrees C. The solubilities of halothane at a concentration of 0.77% v/v in 5% carbon dioxide in air at 37 degrees C were determined for a variety of equine tissues. The mean values for the tissue/gas partition coefficients for visceral tissue taken from 36 horses were 5.42 for whole brain, 4.82 for grey matter, 7.41 for white matter, 4.18 for myocardium, 2.76 for lung, 8.51 for liver, 3.21 for kidneys, 2.66 for gastrointestinal tract, 1.77 for blood and 2.45 for spleen. The mean coefficients for eight different muscles taken from 23 horses ranged from 2.43 for extensor carpi radialis to 4.91 for psoas m...
Acid-base and electrolyte alterations associated with salivary loss in the pony. Esophageal fistulas were made in 6 ponies to evaluate whole blood acid-base values and serum and salivary electrolyte alterations associated with salivary depletion. Acid-base and electrolyte values remained within normal ranges for 15 days in 3 control ponies fed a pelleted diet through nasogastric tubes. In 6 ponies with esophageal fistulas that were fed the same diet through esophagostomy tubes, hypochloremia and hyponatremia developed during the same period. Serum K concentrations were only marginally depleted, probably because of dietary replacement. Salivary depletion resulted in transie...
Tissue composition and halothane solubility in the horse. The halothane muscle/gas partition coefficients at 37 degrees C for 26 samples of eight different muscles from four horses were found to depend significantly on the fat content of the muscle sample with a regression coefficient of 1.913 (SEM 0.109) per per cent ether-extractable fat content. The blood/gas partition coefficients in 24 horses showed a significant dependence on plasma triglyceride concentration (regression coefficient 0.00084 (SEM 0.00033) per mg dl-1), an insignificant positive dependence on plasma free and total cholesterol concentration and, in a multiple regression analysis, ...
Studies related to the metabolism of anabolic steroids in the horse: the identification of some 16-oxygenated metabolites of testosterone and a study of the phase II metabolism. 1. Isomers of 3,17-dihydroxyandrostan-16-one, 3,16-dihydroxyandrostan-17-one and androstane-3,16,17-triol have been identified as urinary metabolites of testosterone in the horse. 2. Following XAD-2 extraction of urine samples, Sephadex LH-20 chromatography was used to separate the extract into conjugate groups. Metabolites obtained after hydrolysis of the conjugates have been investigated by g.l.c.-mass spectrometry. 3. Testosterone, 3,17-dihydroxyandrostan-16-one and 3,16-dihydroxyandrostan-17-one were found only in the sulphate fraction. 5 alpha-Androstane-3 beta,17 beta-diol, and two isome...
[Evaluation of the performance of horses using pulse rate loading dynamics after basic training]. On the basis of test results, regarding the pulse rate response to the increased load, obtained from 278 three-year-old horses after finishing their elementary training (145 Bohemian warm-blooded horses, 115 Kladrub Black horses and 18 English half-bred horses), a method was worked for the evaluation of their performance. As an evaluating criterion a velocity (v170) was chosen which was obtained from an experimentally determined regression dependence of velocity on the pulse rate at 170 pulses per minute. A set of v170 data were statistically processed and on the basis of quantiles of normal d...
Equine cervical esophagostomy: complications associated with duration and location of feeding tubes. Cervical esophagostomy for tube feeding was evaluated in 11 ponies. Minor complications responded to supportive therapy in 8 ponies. Two died of complications, and 1 pony had a permanent fistula because of persistent infection. There was a positive correlation between the duration of tube feeding and the event of closure of the esophageal stoma after the tube was removed. There was no difference in the frequency of complications related to duration of tube feeding. When the distal end of the feeding tube was located in the thoracic portion of the esophagus, instead of in the stomach, tubes wer...
Muscle fibre composition and glycogen depletion in horses competing in an endurance ride. An investigation into fibre composition and glycogen depletion pattern within the middle gluteal of 16 horses participating in an 80 km endurance ride was carried out. Although the proportion of slow twitch high oxidative (ST) fibres in the horses varied between 7 and 38 per cent, it was found that the horses with the highest proportion of these fibres usually had the best performance records. The cross-sectional area of the fast twitch low oxidative (FT) fibres was greatest, with the ST and fast twitch high oxidative (FTH) being similar in size. Most marked histological evidence of glycogen d...
Isolation of cellulolytic phycomycete fungi from the caecum of the horse. Microscopic examination of horse caecum contents revealed vegetative growth of phycomycete fungi on particles of digesta, and uniflagellated cells similar to fungal zoospores in the liquid phase. Three morphologically distinct isolates of strictly anaerobic phycomycete fungi were obtained from the caecum contents and cultured in vitro. Two of the isolates were able to utilize a wide range of plant carbohydrates for growth, including alpha-cellulose, xylan and particulate starch, and extensively digested water-insoluble plant tissues.
Effects of xylazine and ketamine hydrochloride on the electroencephalogram and the electrocardiogram in the horse. A continuous series of electroencephalograms (EEG) was obtained from each of 6 mature horses which had been given xylazine and ketamine hydrochloride IV. Electrocardiograms and respiratory rates were also obtained. The EEG of the unsedated standing adult horse displayed a dominant fast activity in the range of 25-35 Hz, 5-30 microV superimposed over slower 1-4 Hz, 10-50 microV activity with occasional 10-14 Hz, 10-40 microV spindle-type activity. The xylazine-sedated horse displayed hypersynchronous EEG patterns, with the dominant activity being 1-3 Hz, 10-70 microV with overlying mixed freque...
Procedure for granulokinetic studies in the horse with chromium-51. A procedure with chromium-51 (51Cr) as the cell label that maintains high-cell viability for studying granulocyte kinetics in horses is described. The procedure combines and modifies several methods for isolating leukocytes and granulocytes for use in the horse when a large volume of labeled cells is required. Also described is an improved technique for measuring granulocyte specific activity in large serial blood samples, using a Ficoll-sedimentation method. The procedure should be useful for determining granulocyte kinetics in the horse, the only major domestic species for which such data ar...
The actual cautery — myth and reality in the art of firing. The historical development of "firing" as a treatment for various complaints in animals and man is followed from the first surviving written account by Vegetius (approximately AD 500) to the present day. Changing concepts as to the mechanism of action of the actual cautery are examined in relation to physiological understanding at various times and conflicting views and evident fallacies are discussed. It is of particular interest that firing of "sinewes" (tendons and ligaments) was expressly forbidden until the 18th century. It is concluded that "firing" is an outmoded practice for which ther...
Effects of etiocholanolone and prednisolone on intravascular granulocyte kinetics in horses. The functional capacity of the marrow granulocyte reserve (MGR) in 4 adult horses was studied, using 51Cr-labeled leukocytes. The mean increase in the peripheral granulocyte count following injections of etiocholanolone (0.3 mg/kg) was 870 granulocytes/mm3, and the mean increase following prednisolone administration (200 mg) was 5,880 granulocytes/mm3. Etiocholanolone failed to mobilize the MGR and decreased the rate of granulocyte egress from the blood. Prednisolone rapidly mobilized the MGR and markedly decreased the granulocyte specific activity during the first 3 hours after injection.
