Sodium is an essential electrolyte in horses, involved in maintaining fluid balance, nerve function, and muscle contraction. It plays a significant role in the regulation of osmotic pressure within cells and the overall homeostasis of bodily fluids. Horses obtain sodium primarily through their diet, and it can be supplemented through salt blocks or electrolyte solutions, especially in cases of heavy sweating or increased physical activity. Imbalances in sodium levels, either deficiency or excess, can impact a horse's health and performance. This page compiles peer-reviewed research studies and scholarly articles that explore the metabolism, dietary requirements, and physiological effects of sodium in equine health.
Riond JL, Leoni S, Wanner M.Three feeding methods were compared in 36 4- to 6-year-old Franche-Montagne horses during the military school of St-Luzisteig (GR) of Spring 1992. The horses were separated into 3 groups: a group with the traditional oats-hay ration (OH), a group with a pelleted feed and hay ration (PFH), and a group with the complete diet (CD). Feed analyses were performed and food consumption, eating behavior and digestibility were studied. The horses received their daily amount of feed in 3 portions covering the requirements for a medium work: OH = 8 kg hay and 3 kg oats, PFH = 8 kg hay and 3 kg pelleted fe...
Friend TH.The aim of this study was to characterize progressive dehydration, stress responses, and water consumption patterns of horses transported long distances in hot weather and to estimate recovery time after 30 h of transport. Thirty adult mares and geldings were deprived of access to feed and water for 6 h, blocked by age, sex, breed, and body condition score, and assigned to one of the following treatments: penned, offered water (Penned/Watered, n = 5); penned, no water (Penned, n = 5); transported, offered water (Transported/Watered, two groups of n = 5); or transported, no water (Transported, ...
Fenger CK, McKeever KH, Hinchcliff KW, Kohn CW.To determine components of the increase in oxygen consumption (VO2) and evaluate determinants of hemoglobin saturation (SO2) during incremental treadmill exercise in unfit horses. Methods: 7 unfit adult mares. Methods: Horses performed 1 preliminary exercise test (EXT) and 2 experimental EXT. Arterial and mixed venous blood samples and hemodynamic measurements were taken during the last 30 seconds of each step of the GXT to measure PO2, hemoglobin concentration ([Hb]), SO2, and determinants of acid-base state (protein, electrolytes, and PCO2). Results: Increased VO2 during exercise was facilit...
Suwannachot P, Verkleij CB, Weijs WA, van Weeren PR, Everts ME.We investigated the effect of training on the Na+, K+-ATPase concentration in foal skeletal muscle by measurement of [3H]ouabain binding. From the 7th day after birth, 12 foals were divided in 3 groups: a) staying in a box stall (Box); b) staying in a box stall with a training regimen of an increasing number of sprints per day (Training); and c) staying on pasture (Pasture). Euthanasia was performed after 5 months. In semitendinosus muscle, the concentration of [3H]ouabain binding sites (pmol/g wet wt) was 181 +/- 6 in the Box, 220 +/- 15 in the Training, and 197 +/- 8 in the Pasture group (al...
Sweeney CR, Scanlon T, Russell GE, Smith G, Boston RC.To determine application rate and effectiveness of sodium bisulfate to decrease the fly population in a horse barn environment. Methods: 12 privately owned farms in southeastern Pennsylvania. Methods: Application rates of sodium bisulfate were approximately 2.3 kg/stall, 1.1 kg/stall, and 0.5 kg/stall. Two or 3 stalls were treated, and 1 or 2 stalls were not treated (control stalls) at each farm. Farm personnel applied sodium bisulfate in treated stalls daily for 7 days. Fly tapes were hung from the same site in treated and control stalls. After 24 hours, the fly tape was removed, flies adheri...
Forro M, Cieslar S, Ecker GL, Walzak A, Hahn J, Lindinger MI.The purposes of this study were 1) to determine the compartmentation of body water in horses by using indicator dilution techniques and 2) to simultaneously measure bioelectrical impedance to current flow at impulse current frequencies of 5 and 200 kHz to formulate predictive equations that could be used to estimate total body water (TBW), extracellular fluid volume (ECFV), and intracellular fluid volume (ICFV). Eight horses and ponies weighing from 214 to 636 kg had catheters placed into the left and right jugular veins. Deuterium oxide, sodium thiocyanate, and Evans blue were infused for the...
Polack EW, King JM, Cummings JF, Mohammed HO, Birch M, Cronin T.To compare concentrations of trace minerals in the spinal cord of horses with equine motor neuron disease (EMND) with those of horses without neurologic disease (control horses). Methods: 24 horses with EMND and 22 control horses. Methods: Spinal cord trace mineral concentrations in horses with EMND and control horses were analyzed by use of inductively coupled plasma atomic emission spectroscopy (calcium, phosphorus, sodium, potassium, magnesium, copper, iron, manganese, nickel, zinc, aluminum, cobalt, and chromium), atomic absorption spectrophotometry (lead and cadmium), flameless atomic abs...
Kingston JK, McCutcheon LJ, Geor RJ.To quantify total fluid loss in sweat of Thoroughbreds during >3 hours of low-intensity exercise in controlled conditions and to calculate and compare estimated ion losses in sweat, according to 3 methods. Methods: 6 exercise-trained Thoroughbreds. Methods: Fluid and ion losses in sweat were measured in 6 horses exercising at 40% of the speed that elicited maximum oxygen consumption for 45 km. Horses were given a 15-minute rest period at the end of three 15-km exercise phases. Horses completed 2 exercise trials. Ion losses in sweat were calculated, using measurements of local sweating rate and...
Aguilera-Tejero E, Estepa JC, López I, Bas S, Mayer-Valor R, RodrÃguez M.The acid-base status of venous blood was studied in 17 show jumpers before and after exercise using both a traditional and a quantitative approach. Partial pressure of carbon dioxide (PCO(2)), pH, haemoglobin, and plasma concentrations of sodium (Na(+)), chloride (Cl(-)), potasium (K(+)), ionized calcium (Ca(2+)), total proteins, albumin, lactate and phosphorus were measured in jugular venous blood samples obtained before and immediately after finishing a show jumping competition. Bicarbonate, anion gap and globulin concentration were calculated from the measured parameters. 'Quantitative anal...
Neild D, Chaves G, Flores M, Mora N, Beconi M, Agüero A.The aim of the study was to evaluate equine sperm membrane integrity using the hypoosmotic swelling (HOS) test and to correlate this test with different sperm parameters in raw and frozen thawed semen. The HOS solutions were made with fructose, sucrose, lactose and sodium citrate each at 300, 150, 100, 50 and 25 mosm. Maximum numbers of swollen spermatozoa were observed in solutions of fructose, sucrose and lactose each at 100, 50 and 25 mosm. Correlations between progressive motility, morphologically normal spermatozoa and the HOS test were r = 0.75 and r = 0.51 in raw semen and r = 0.26 and ...
Lindinger MI, McCutcheon LJ, Ecker GL, Geor RJ.This study determined the plasma volume (PV) and ion responses to heat acclimation and exercise in six trained Thoroughbred horses during 21 days of exposure to heat and humidity (33 degrees C, 83% relative humidity) for 4 h/day. During the 2nd h on days 0, 3, 7, 14, and 21, horses performed a standardized treadmill test, running at 50% of peak O(2) uptake until pulmonary artery temperature reached 41.5 degrees C. Heat acclimation resulted in an increase in PV from 21.3 +/- 1.1 liters on day 0 to 24.3 +/- 1.0 liters on day 14, returning to 22.6 +/- 0.9 liters on day 21. The corresponding total...
Beech J, Fletcher JE, Erwin K, Lindborg SR.To determine sensitivity of equine skeletal muscle to tetrodotoxin and compare that with sensitivity of murine and human skeletal muscles. Methods: Semimembranosus, vastus lateralis, triceps brachii, and masseter muscle specimens from 22 euthanatized horses, vastus lateralis muscle biopsy specimens from 25 clinically normal humans, and diaphragmatic muscle specimens from 6 mice. Methods: Electrically elicited twitch responses were measured in muscle specimens incubated in medium alone and with tetrodotoxin (100 nM, 400 nM, 1.6 microM for equine specimens and 100 nM, 200 nM, 400 nM, 800 nM, 1.6...
Greene S, Keegan R, Brown J, Kingston J, Bayly WM.This study evaluated the effects of pre-exercise frusemide administration and hypertonic saline (H) infusion during anaesthesia on arterial pH, blood gases and electrolytes in 6 Thoroughbred horses anaesthetised immediately post exercise. Horses received either frusemide (F) (0.5 mg/kg, i.v.) or a saline placebo (P) injection 4 h prior to treadmill exercise. Exercise consisted of a 3 min warm-up at 40% VO2max followed by exercise to fatigue. Detomidine (40 micrograms/kg, i.v.) was given within 5 min of stopping and followed 5 min later by zolazepam-tiletamine (1.25 mg/kg, i.v.) to induce anaes...
Valberg SJ, Mickelson JR, Gallant EM, MacLeay JM, Lentz L, de la Corte F.The purpose of this study was to determine if chronic exertional rhabdomyolysis (ER) in Quarter Horses and Thoroughbreds represents one or several distinct myopathies. Eighteen Quarter Horses and 18 Thoroughbreds with ER were selected from cases presented to the Veterinary Hospital on the basis of a history of ER, assessment of muscle histopathology, and serum CK activity before and 4 h post exercise. In addition, 2 of 3 of the following parameters were evaluated: muscle glycogen concentrations, thyroid hormones (T3, T4), fractional excretion (FE) of sodium, potassium and chloride. The CK resp...
McCutcheon LJ, Geor RJ, Shen H.The objective of this study was to determine the effects of 10 consecutive days of moderate intensity training on 1) the concentration of middle gluteal muscle Na(+)-K(+)-ATPase as determined by vanadate-facilitated 3H[ouabain binding; and 2) plasma potassium regulation before, during and after exercise at 100% of the pre-training maximum rate of oxygen consumption (VO2max). Six mature, unfit Thoroughbred horses completed both incremental (for determination of VO2max) and high-intensity exercise protocols before (HI1) and after (HI2) training. There additional horses undertook no training or e...
Düsterdieck KF, Schott HC, Eberhart SW, Woody KA, Coenen M.To replace electrolytes lost in sweat during endurance competitions, riders frequently supplement horses with hypertonic oral electrolyte pastes. To determine whether this practice and concurrent administration of the so-called hyperhydrating substance glycerol are of benefit, weight loss, voluntary water intake, plasma osmolality, and plasma protein and electrolyte concentrations were measured in 6 Arabian horses supplemented with a total of 2.4 ml/kg bwt of water (W); 0.2 g/kg bwt KCl and 0.4 g/kg bwt NaCl in 2.4 ml/kg bwt of water (E); or 0.2 g/kg bwt KCl and 0.4 g/kg bwt NaCl in 2.4 ml/kg ...
Schott HC, Düsterdieck KF, Eberhart SW, Woody KA, Refsal KR, Coenen M.Incomplete recovery from endurance exercise after an overnight rest period is reflected by persisting weight loss and an elevated plasma aldosterone concentration, even in successful competitors. To determine whether supplementation with high doses of electrolytes, with or without glycerol, enhances recovery, the following were measured in 6 Arabian horses before and after completion of a 60 km treadmill exercise test simulating an endurance ride and after 12, 24, 48, and 72 h of recovery: bodyweight; plasma osmolality; plasma concentrations of protein, electrolytes, aldosterone and cortisol; ...
Monreal L, Garzón N, Espada Y, RuÃz-Gopegui R, Homedes J.An isotonic electrolyte solution with a composition similar to equine sweat was compared to an isotonic glucose-glycine-electrolyte solution for oral rehydration therapy in exercising horses. Ten horses were dehydrated by using frusemide and allocated randomly to receive 4 different oral solutions: isotonic sweat-like electrolyte solution, half-strength hypotonic electrolyte solution, isotonic glucose-glycine-electrolyte solution, and plain water. Solutions were given by nasogastric tube using the same volume as the bodyweight lost by each horse. Blood samples were collected before and through...
Kronfeld DS, Ferrante PL, Taylor LE, Tiegs W.Increases in blood [H+] and lactic acid [La-] attend fatigue. We applied Stewart's physiological model of acid-base status and simple regressions to assess the importance of independent variables and [La-] on [H+] during repeated sprints. Eight well-conditioned Arabians performed 9 sprints. Plasma from jugular vein samples was analysed for pH, PCO2, Na+, K+ and Cl-. Plasma [La-] was calculated from blood [La-], plasma [H+] from pH, SID from Na+, K+, Cl- and La-, Atot from pH, PCO2 and SID. Peaks for SID, PCO2 and [H+] were reached at sprint 1, -2 and -3, respectively. At sprint 3, the 5.7 nmol...
Waelchli RO, Jaworski T, Ruddock WD, Betteridge KJ.Equine blastocyst fluid has a lower [Na+], a higher [K+] and a lower osmolality than does normal blood serum. Based on the assumptions that the sodium pump is primarily responsible for fluid accumulation and that ions transported actively into the blastocyst increase blastocyst osmolality above that of the external medium, we hypothesized that the [Na+] and the osmolality of mare uterine fluid are lower than those of blastocyst fluid. Microdialysis and ion chromatography were used to estimate [Na+] and [K+] of uterine fluid. Mares (n=10) were used for in vivo measurements at different stages o...
McCutcheon LJ, Geor RJ, Ecker GL, Lindinger MI.This study examined sweating responses in six exercise-trained horses during 21 consecutive days (4 h/day) of exposure to, and daily exercise in, hot humid conditions (32-34 degrees C, 80-85% relative humidity). On days 0, 3, 7, 14, and 21, horses completed a standardized exercise test on a treadmill (6 degrees incline) at a speed eliciting 50% of maximal O(2) uptake until a pulmonary artery temperature of 41.5 degrees C was attained. Sweat was collected at rest, every 5 min during exercise, and during 1 h of standing recovery for measurement of ion composition (Na(+), K(+), and Cl(-)) and swe...
Gaustad G, Dolvik NI, Larsen S.To compare effects of intra-articular injection of 2 ml of 0.9% NaCl solution with rest alone for treatment of horses with traumatic arthritis. Methods: 38 Standardbred horses with moderate to severe lameness that resulted from traumatic arthritis. Methods: Horses were stratified on the basis of number of affected joints. In each stratum, horses were allocated randomly to treatment groups (intraarticular injection of 2 ml of 0.9% NaCl solution vs rest only). Treatment was for a period of 3 weeks. Horses were inspected weekly with a final examination 2 to 4 weeks after completion of treatment. ...
Dyke TM, Hinchcliff KW, Sams RA.The objectives of this study were to determine the effect of phenylbutazone premedication on the pharmacokinetics and urinary excretion of frusemide in horses; and on frusemide-induced changes in urinary electrolyte excretion. Six Standardbred mares were used in a 3-way crossover design. The pharmacokinetics and renal effects of frusemide (1 mg/kg bwt i.v.) were studied with and without phenylbutazone premedication (8.8 mg/kg bwt per os 24 h before, followed by 4.4 mg/kg bwt i.v. 30 min before frusemide administration). A control (saline) treatment was also studied. Administration of frusemide...
Jansson A, Dahlborn K.The effect of feeding frequency and voluntary sodium intake (VSI) on fluid shifts and plasma aldosterone concentration (PAC) were studied at rest and after exercise in six athletic horses. The horses were fed twice a day (2TD) and six times a day (6TD) for 25 days for each protocol, according to a changeover design. VSI was measured by weighing each horse's salt block daily. Feeding 2TD or 6TD caused no major alterations in fluid shifts, but in the 2TD treatment there was a postprandial increase in plasma protein concentration and osmolality that lasted <1 h. PAC and VSI were not affected b...
Grace ND, Pearce SG, Firth EC, Fennessy PF.To determine the changes in Ca, P, Mg, Na, K, S, Cu, Fe and Zn concentrations of milk during the lactation in pasture-fed Thoroughbred mares and then calculate the dietary mineral requirements of the sucking foal and the lactating mare. Methods: Milk was sampled on days 1, 3, 7, 14, 21, 28 and at various times between 55 to 65, 85 to 95 and 135 to 150 days after parturition from 21 pasture-fed mares. The concentrations of macro- and micro-elements in the milk were determined by inductively coupled plasma emission spectrometry. Results: Concentrations (mg/L) of these elements were highest in co...
Tschudi PR.The purpose of this study was to compare the results of horse blood examinations on a portable blood analysis system, i-STAT SDI, with conventional laboratory equipment and to verify the accuracy and precision. The precision within run was high and the coefficients of variation ranged from 0 to 3.85%. The comparative analysis of patient samples with routine methods showed a very strong positive correlation with correlation coefficients above 0.96 for blood gases, pH, glucose, urea, hemoglobin, hematocrit, sodium and potassium, with the exception of chloride where it was 0.867. The i-STAT syste...
Kitchen DL, Merritt AM, Burrow JA.To determine gastric secretory responses in horses treated with histamine and to determine the dose of histamine needed to elicit maximal gastric secretion. Methods: 6 adult horses with an indwelling gastric cannula. Methods: Gastric contents were collected in 15-minute periods, and volume, pH, hydrogen ion concentration, hydrogen ion output, sodium concentration, and sodium output were determined. Values were determined without any treatment (baseline), after administration of pyrilamine maleate (1 mg/kg of body weight, i.v., given during a 15-minute period), and during 1-hour infusions of hi...
Grosenbaugh DA, Gadawski JE, Muir WW.Evaluation of a portable clinical analyzer for determination of blood gas tensions, electrolyte and glucose concentrations, and Hct in a hospital setting. Methods: Prospective study. Methods: 50 dogs, 50 cats, and 28 horses, all clinically normal. Methods: Blood samples were analyzed on a portable clinical analyzer to determine concentrations of sodium, potassium, chloride, BUN, glucose, and ionized calcium and values of Hct, pH, PCO2, and PO2. Values obtained were compared with those obtained from the same blood samples, using a standard automatic analyzer (serum sodium, potassium, chloride, ...
Looney AL, Ludders J, Erb HN, Gleed R, Moon P.To compare, for blood samples from dogs and horses, blood electrolyte concentrations, blood gas partial pressures, and Hct obtained using a handheld analyzer with those obtained using a standard chemistry analyzer and to compare results obtained with the handheld analyzer using warm versus cold test cartridges. Methods: Case series with analysis of split samples. Methods: Blood samples from 22 dogs and 17 horses. Methods: Sodium, potassium, ionized calcium, bicarbonate, and total CO2 concentrations, pH, PO2, PCO2, base excess, and Hct were determined by use of a handheld analyzer and test cart...
van den Berg JS, Guthrie AJ, Meintjes RA, Nurton JP, Adamson DA, Travers CW, Lund RJ, Mostert HJ.The objectives of this trial were to measure the water and electrolyte intake and loss, of horses during road transportation in relatively hot environmental conditions. Six mature, Thoroughbred horses in full training were used in a balanced crossover design. The horses were conditioned on a treadmill for 6 weeks before the start of the trial in order to simulate the type of horse that is transported most often over long distances in South Africa. The horses were assigned randomly to one of 2 treatment groups. On a particular day 3 horses were transported, while the other horses served as cont...
Sosa León LA.One of the most common consequences of prolonged exercise is fluid and electrolyte depletion. Fluid and electrolyte losses during exercise may limit the horse's performance and, in extreme cases, jeopardize its health. To avoid or treat the deleterious effects of dehydration, fluid and electrolyte supplementation is essential. This article provides recommendations for fluid and electrolyte supplementation for horses involved in endurance-related events.
Daden R, Zarhouni FZ, Chakir J, Piro M, Achaâban MR, Ouassat M, El Allali K.To evaluate the effect of plasmapheresis on clinical, hematological, and biochemical parameters after exercise, a plasmapheresis session was realized on six jumping horses (plasmapheresis group) that underwent three consecutive days of physical graded exercise. The control group (n = 6) went through the same exercise but not subjected to the plasmapheresis session. Seventeen milliliters of plasma/kg of body weight was harvested from each horse. The procedure was well tolerated by the horses. The plasmapheresis leads to a significant increase of the hemoglobin, hematocrit, red blood cell, whit...
Thomson JR, McPherson EA.When stabled in a controlled environment, horses effected with chronic obstructive pulmonary disease (COPD) became clinically asymptomatic in 4 to 32 days (mean [+/-sd] 9.1 +/- 4.9 days), the time being influenced most by the severity of the disease judged on maximum intrathoracic pressure change (Max delta Ppl) and the age of the animal. Sodium cromoglycate, a drug widely used for prophylaxis of allergic respiratory disease in man, was administered by inhalation to 56 COPD-affected horses. The results showed that a linear response existed between the number of successive days treatment with t...
Marlin DJ, Scott CM, Mills PC, Louwes H, Vaarten J.The effects of administering (1) 6L isotonic oral rehydration solution (ORS), similar in composition to plasma (except for an elevated potassium concentration) and with an osmotic skeleton and (2) 6L water (no osmotic skeleton), were evaluated in five thoroughbred horses following exercise-induced dehydration. The horses were exercised on a treadmill for 10 min at walk (1.7 m.s-1; approximately 15% VO2max), 40 min at trot (3.7 m.s-1; approximately 25% VO2max) and 10 min at walk (1.7 m.s-1; approximately 15% VO2max). Exercise was undertaken on a 3 degrees incline at 30 degrees C/80% RH. Solutio...
Schatzmann U, Gugelmann M, Von Cranach J, Ludwig BM, Rehm WF.Carprofen, flunixin meglumine and placebo in the form of a physiological solution of sodium chloride were tested in an open randomised cross-over trial for analgesic efficacy in horses with two external skin-stimulation systems. Both systems, the withers model and the "heating element" model, were compared in order to find an optimal way to measure pain perception after stimulating the skin with high temperature. No analgesic effect of flunixin or carprofen could be demonstrated when using the withers model. In the "heating element" model, a 1.1 mg/kg i.v. dose of flunixin meglumine failed to ...
Hoffman RM, Hess TM, Williams CA, Kronfeld DS, Griewe-Crandell KM, Waldron JE, Graham-Thiers PM, Gay LS, Splan RK, Saker KE, Harris PA.To test the hypothesis that endurance performance may be related quantitatively to changes in blood, we measured selected blood variables then determined their reference ranges and associations with speed during an 80 km race. The plan had 46 horses in a 2 x 2 factorial design testing a potassium-free electrolyte mix and a vitamin supplement. Blood samples were collected before the race, at 21, 37, 56 and 80 km, and 20 min after finishing, for assay of haematocrit, plasma pH, pO2, pCO2, [Na+], [K+], [Ca++], [Mg++], [Cl-], lactate, glucose, urea, cortisol, alpha-tocopherol, ascorbate, creatine ...
Grace ND, Rogers CW, Firth EC, Faram TL, Shaw HL.To measure the nutritive value of pasture in terms of digestible energy intake (DEI) and dry matter (DM) digestibility, and the effects of increased calcium (Ca) intakes on apparent mineral absorption and bone characteristics in grazing weanling Thoroughbreds. Methods: DM intake (DMI) and DEI were determined in 16 weanling Thoroughbreds grazing pasture from their daily faecal DM output, measured over 8 days, divided by the DM indigestible fraction (1-digestible DM) determined in a 6-day digestibility trial. The DM, gross energy content, crude protein, soluble carbohydrate, acid detergent fibre...
Bohanon TC, Schneider RK, Weisbrode SE.Six normal horses received 3 intra-articular injections of sodium monoiodoacetate (MIA) in the distal intertarsal (DIT) and tarsometatarsal (TMT) joints of one hindlimb. Injections were at three week intervals, and post injection pain was controlled with routine administration of phenylbutazone for five days following each injection. All horses underwent a gradually increasing exercise programme consisting of walking and trotting beginning one week after the first injection and continuing for 24 weeks. All treated joints showed increasingly severe radiographic evidence of degenerative joint di...
Spooner HS, Nielsen BD, Schott HC, Harris PA.Excessive sweat loss during endurance exercise may lead to electrolyte disturbances and previous research suggests dietary factors may affect hydration status. While investigating the effect of dietary fibre type on hydration status, sweat samples were collected which allowed for the evaluation of sweat composition in horses consuming forage-based, low sodium (Na) rations. Objective: To investigate sweat composition in Arabian horses performing endurance type exercise while fed forage-based, rations low in Na. Methods: Six 2-year-old Arabian horses were fed, according to a replicated 3 × 3 La...
Campbell-Thompson ML, Merritt AM.Equine gastric secretion was studied using a gastric cannula model after fasting (basal) and pentagastrin infusion. Gastric secretory rate, pH, osmolality, and electrolyte concentrations and outputs were determined over a 5-h period. Dose-response tests estimated that the maximally effective intravenous dose of pentagastrin was between 3 and 6 micrograms.kg-1.h-1. Basal secretory rate was 278 +/- 29 (SE) ml/15 min, and the pH was 2.00 +/- 0.31. Pentagastrin infusion at 6 micrograms.kg-1.h-1 increased secretory rate to 533 +/- 60 ml/15 min and decreased pH to 1.41 +/- 0.11. Basal gastric acid c...
Alsobayil FA, El-Shafaey ES, Sadan M, Alshoshan AA.Sevoflurane is a volatile anesthetic agent that has become popular in the field of large animal anesthesia. The aim of this study was to evaluate the use of sevoflurane in adult healthy donkeys. Six male, adult, healthy donkeys were premedicated with xylazine (1Â mg/kg IV), induced with thiopental (5Â mg/kg IV), and then maintained for 90Â minutes with sevoflurane in 100% oxygen at a flow rate of 6Â L/min with spontaneous breathing. Rectal temperature (RT), respiratory rate, heart rate (HR), oxygen hemoglobin saturation (OHS), and mean arterial blood pressure (MBP) were measured before and 20Â...
Kitchen DL, Merritt AM, Burrow JA.To determine gastric secretory responses in horses treated with histamine and to determine the dose of histamine needed to elicit maximal gastric secretion. Methods: 6 adult horses with an indwelling gastric cannula. Methods: Gastric contents were collected in 15-minute periods, and volume, pH, hydrogen ion concentration, hydrogen ion output, sodium concentration, and sodium output were determined. Values were determined without any treatment (baseline), after administration of pyrilamine maleate (1 mg/kg of body weight, i.v., given during a 15-minute period), and during 1-hour infusions of hi...
Suwannachot P, Verkleij CB, Weijs WA, van Weeren PR, Everts ME.We investigated the effect of training on the Na+, K+-ATPase concentration in foal skeletal muscle by measurement of [3H]ouabain binding. From the 7th day after birth, 12 foals were divided in 3 groups: a) staying in a box stall (Box); b) staying in a box stall with a training regimen of an increasing number of sprints per day (Training); and c) staying on pasture (Pasture). Euthanasia was performed after 5 months. In semitendinosus muscle, the concentration of [3H]ouabain binding sites (pmol/g wet wt) was 181 +/- 6 in the Box, 220 +/- 15 in the Training, and 197 +/- 8 in the Pasture group (al...
Payne J, Farris R, Parker G, Bonhotal J, Schwarz M.Sodium pentobarbital, a euthanasia drug, can persist in animal carcasses following euthanasia and can cause secondary toxicosis to animals that consume the remains. This experiment was conducted to observe the effects of composting on euthanized horse carcass degradation and sodium pentobarbital residues in compost material up to 367 d. Six separate compost bins were constructed on pastureland. Three bins served as the control while 3 served as the treatment. The carbonaceous material, or bulking agent, consisted of hardwood chips mixed with yard waste wetted to approximately 50% moisture cont...
Harkins JD, Kamerling SG.There is considerable debate regarding the ergogenic effects of sodium bicarbonate (NaHCO3) on racing performance in horses. Anecdotal evidence suggests that NaHCO3 improves performance by increasing the buffering capacity of the blood and delaying the onset of hydrogen ion-induced fatigue. In a cross-over study, 16 Thoroughbred racehorses were given an aqueous solution of NaHCO3 (0.4 g/kg in 1 litre H2O) or a control treatment (1 litre H2O) before a 1600-m race. Treatments were administered 3 h before the race, which was the time to peak buffering capacity (2.5-3.0 h) determined in a separate...
Melo UP, Palhares MS, Ferreira C, Leme FOP, Gheller VA.This study aimed to evaluate the effects of the total parenteral nutrition associated with glutamine, enteral fluid therapy with or without glutamine, and fluid therapy on the acid-base and electrolyte balance of horses starved after exploratory laparotomy. Sixteen healthy male and female adult horses of mixed breed, aged between 4 and 14 years, and having a mean body weight of 248.40 ± 2.28 kg and a body score index of 3-4 (scale of 1-5) were divided into four groups with four animals per group. After an adaptation period of 30 days, they were randomly divided into four experimental groups: ...
Pantaleon LG.Fluid therapy is an important component of resuscitation and treatment of critically ill equine patients. However, the decision of which fluid type to use in certain critical situations is somewhat controversial. This article focuses on the potential benefits of performing small-volume resuscitation in critically ill horses by combining hypertonic saline with a colloid (e.g., hetastarch).
Dowling BA, Dart AJ, Matthews SM.To evaluate chemical arthrodesis using sodium monoiodoacetate for treatment of degenerative joint disease of the tarsometatarsal and distal intertarsal joints. Methods: Retrospective clinical study. Methods: Horses were diagnosed with degenerative joint disease of one or more of the tarsometatarsal or distal intertarsal joints based on history, lameness examination, radiographic findings and, in some cases, response to intra-articular anaesthesia or medication. Intra-articular injections of sodium monoiodoacetate were performed using 23 gauge needles in the sedated, standing horse. Positive co...
De Pedro P, Wilkins PA, McMichael MA, Dirikolu L, Lascola KM, Clark-Price SC, Boston RC.To determine endogenous production of L-lactate and the clearance of exogenous sodium L-lactate (ExLC) in healthy adult horses. Methods: A sodium L-lactate solution (1 mmol/kg body weight qs to 500 mL final volume in 0.9% NaCl) was adminstered IV over 15 minutes. Blood samples for L-lactate concentration [LAC] measurement were collected immediately prior to infusion, at 5, 10, and 15 minutes during infusion and at 1 minute intervals for 15 minutes, at 30, 45, 60, 120, and 180 minutes postinfusion. Disposition modeling and pharmacokinetic analysis was performed using proprietary software. Metho...
Ziemer EL, Parker HR, Carlson GP, Smith BP, Ishizaki G.An 11-year-old Quarter Horse mare and a 2-year-old Quarter Horse colt with clinical diagnoses of renal tubular acidosis (RTA) were donated to the University of California Veterinary Medical Teaching Hospital. A series of diagnostic tests was performed in an attempt to characterize the type and cause of RTA in these horses. Endogenous creatinine clearance and sodium sulfanilate clearance were within reference ranges; thus, no abnormality of glomerular function was detected. To assess renal tubular function in response to acid loading, each horse was given 0.1 g of NH4Cl/kg of body weight via na...
Fielding CL, Magdesian KG, Meier CA, Rhodes DM.To describe the clinical and laboratory changes associated with the use of IV0.9% sodium chloride and a commercially available acetated fluid (CAF) to treat endurance horses requiring emergency medical treatment. Methods: Randomized, controlled clinical trial from 2007 to 2010. Methods: Emergency treatment centers of the Western States 100-mile (220 km) endurance ride. Methods: Twelve horses requiring emergency medical treatment in the form of IVfluids completed the study. Methods: Horses were assigned to either the 0.9% sodium chloride group (6 horses) or CAF group (6 horses) and received a t...
Waller A, Lindinger MI.Sodium acetate (NaAcetate) has received some attention as an alkalinizing agent and possible alternative energy source for the horse, however the effects of oral administration remain largely unknown. The present study used the physicochemical approach to characterize the changes in acid-base status occurring after oral NaAcetate/acetic acid (NAA) administration in horses. Methods: Jugular venous blood was sampled from 9 exercise-conditioned horses on 2 separate occasions, at rest and for 24 h following a competition exercise test (CET) designed to simulate the speed and endurance test of 3-da...
Sneddon JC, van der Walt JG, Mitchell G.This study set out to investigate tolerance of the body water pool to short-term water deprivation in horses and, in particular, to assess whether feral horses from the Namib Desert showed tolerance to dehydration superior to Transvaal. Hydration status was compared in six feral horses from the Namib Desert and in six Boerperd farm horses under conditions of normal hydration and after 72 h of dehydration. Under normal hydration, the two groups did not differ significantly in water intake, plasma sodium and potassium concentrations, plasma osmolality, hematocrit, total plasma protein, body wate...
Tappenbeck K, Hoppe S, Geburek F, Feige K, Huber K.By blocking the enteric nervous system (ENS) using tetrodotoxin (TTX), previous studies have documented the contractility-enhancing (CE) effects of lidocaine in equine intestinal smooth muscle (SM) at the level of SM cells and/or interstitial cells of Cajal (ICC). The present study examined the impact of ENS deactivation on CE lidocaine effects, and investigated the effects of lidocaine on ENS activity. TTX application did not affect the CE effects of lidocaine, indicating that these were not mediated by TTX-sensitive sodium channels. Application of TTX or ≥100 mg/L lidocaine reduced ENS a...
Lakritz J, Madigan J, Carlson GP.Hypovolemic hyponatremia attributable to severe fluid and electrolyte alterations was diagnosed in a foal with diarrhea. Subsequent consumption of water resulted in rapid reduction of serum sodium concentration and serum osmolar depression. Clinical signs of neurologic disease developed including blindness, loss of menace response, and seizures. Treatment of this condition with IV administered fluids included hypertonic saline solution (7.2%; 2 ml/kg of body weight), and frequent monitoring of serum electrolyte concentrations and osmolality resulted in gradual correction of the fluid and elect...
Murphy JR, McPherson EA, Lawson GH.80 mg sodium cromoglycate (SCG) was administered by inhalation to two COPD-affected animals known to have respiratory hypersensitivity to Micropolyspora faeni. SCG treatment 20-30 minutes prior to inhalation challenge with M. faeni prevented exacerbation of respiratory disease, usually seen 4-8 hours after challenge. duration of protection against antigen challenge after a single SCG treatment was 4-5 days. The duration of protection was not prolonged by reducing the frequency of antigen challenge. Multiple antigen challenge, using M. faeni and Aspergillus fumigatus, shortened the protective p...
Weiss DJ, Geor R, Smith CM, McClay CB.Echinocytes have been incriminated in the pathogenesis of exertional diseases in horses. To evaluate the hypothesis that echinocytes are dehydrated erythrocytes, we decreased blood sodium and potassium concentrations in 4 horses by administering furosemide (1.0 mg/kg of body weight, q 12 h) for 2 days and we monitored CBC, serum and erythrocyte sodium and potassium concentrations, and echinocyte numbers. Serum sodium concentration decreased progressively over the 48 hours of furosemide administration, then returned to near baseline concentration at 168 hours. A statistically significant decrea...
Schott HC, Düsterdieck KF, Eberhart SW, Woody KA, Refsal KR, Coenen M.Incomplete recovery from endurance exercise after an overnight rest period is reflected by persisting weight loss and an elevated plasma aldosterone concentration, even in successful competitors. To determine whether supplementation with high doses of electrolytes, with or without glycerol, enhances recovery, the following were measured in 6 Arabian horses before and after completion of a 60 km treadmill exercise test simulating an endurance ride and after 12, 24, 48, and 72 h of recovery: bodyweight; plasma osmolality; plasma concentrations of protein, electrolytes, aldosterone and cortisol; ...
Taylor LE, Ferrante PL, Kronfeld DS, Meacham TN.Seven Arabian horses performed a standard incremental exercise test on a high-speed treadmill at 6% slope then were randomly assigned to two diets, a control diet of ground hay and concentrates and a similar diet with 10% added fat (by weight). Horses were sprint-trained 4 d/wk, and two additional exercise tests were performed at 5-wk intervals. Heart rates and rectal temperatures were monitored and venous blood samples were collected at rest and at each speed increment. Whole blood was analyzed for glucose, lactate, and hemoglobin concentrations, and plasma was analyzed for pH, pCO2, albumin,...
