Electrolytes are minerals that carry an electric charge and are essential for various physiological functions in horses. These minerals include sodium, potassium, chloride, calcium, and magnesium, among others. Electrolytes are involved in maintaining fluid balance, nerve function, muscle contraction, and acid-base balance in equine bodies. Imbalances or deficiencies in electrolytes can occur due to factors such as exercise, diet, or illness, affecting a horse's performance and health. This page compiles peer-reviewed research studies and scholarly articles that explore the role, regulation, and impact of electrolytes on equine physiology and performance.
Hansen TO, White NA, Kemp DT.Total parenteral nutrition was accomplished in 4 healthy adult horses. During the 10-day study, the horses were not permitted to ingest food or water. Body weight was maintained at 94% of initial values without clinical evidence of dehydration. Serum urea nitrogen and triacylglycerol concentrations decreased during the study, without other significant hematologic or biochemical changes. Horses adapted without problems to the routine of IV feeding and confinement. All horses were healthy at the conclusion of the study. It was concluded that intravenous feeding with a lipid-glucose-amino acid-el...
Rapp HJ.During the combination of oral and intravenous application of saline solution for treatment of the COPD of horses the level of hydraemia basing on the total protein concentration in the serum, the urine production and the specific weight of urine was determined. Additionally the development of serum concentration and of renal excretion rates of potassium, calcium and magnesium were ascertained. The level of hydraemia resulting from the combined method is almost identical with the solely intravenous performed hyperinfusion therapy. Due to the excessive application of fluid an extremely high lev...
Mayhew IG, Ferguson HO.A group of 834 Thoroughbred horses was surveyed on four central Florida farms for clinical and epidemiologic features of anhidrosis. In addition, comparative analysis was made of serum thyroxine, serum electrolytes, and fractional urinary electrolyte excretion ratios. An overall disease prevalence of 6.12% was observed. Training horses and nonpregnant broodmares had a predilection for the disease. Adolescent horses were infrequently affected. There was no correlation with sex or color. Comparative clinical signs, related to thermoregulatory compromise, included tachypnea and hyperthermia. Long...
Genetzky RM, Loparco FV, Ledet AE.A 72-hour water deprivation test was performed in 12 horses to determine clinical pathologic changes. Reference values for electrolyte (X) clearance, expressed as a percentage of creatinine clearance (CLCR; %CLCRX), were also determined. A comparison was made between urine concentration measurement techniques. Results of %CLCRX determination in 12 horses before water deprivation were 0.034 +/- 0.095 %CLCRNa, 42.4 +/- 9.8 %CLCRK, 0.352 +/- 0.190 %CLCRCl, and 0.710 +/- 0.250 %CLCRP. During water deprivation, there was individual variation for electrolyte clearances, but Na excretion increased si...
Divers TJ, Whitlock RH, Byars TD, Leitch M, Crowell WA.Six horses had been admitted to the hospital because of illness other than renal failure; diarrhoea, myositis, abdominal pain and/or suspected bacterial sepsis. Hypotension and disseminated intravascular coagulopathy were frequent findings in the horses. Abnormally high serum creatinine concentration and urine specific gravity of less than 1.022 were found in the horses with acute renal failure. Hyponatraemia and hypochloraemia were the most common abnormal electrolyte findings. Pronounced hyperkalaemia was not found. Variable degrees of tubular necrosis were seen in three of the four horses t...
Ziemer EL, Parker HR, Carlson GP, Smith BP.Two horses were admitted separately for evaluation and treatment of profound hyperchloremic metabolic acidosis without azotemia. One, an 11-year-old Quarter Horse mare, had been depressed and ataxic for 2 days. The other, a 2-year-old Quarter Horse colt, had a 6-week history of depression, anorexia, and weight loss. Both horses responded to fluid and electrolyte therapy, but required daily oral administration of sodium bicarbonate for maintenance. In each case, the diagnosis was renal tubular acidosis.
Rose RJ, Gibson KT, Suann CJ.Five standardbred geldings were given 1 mg/kg bodyweight of frusemide by intramuscular injection to induce mild dehydration. After food and water deprivation overnight, the mean weight loss was 24.4 +/- 1.8 kg (5.5 per cent of bodyweight). The horses were then given an equivalent volume of an oral glucose-glycine-electrolyte solution by stomach tube. No more than 10 litres was given every 30 minutes until the calculated bodyweight loss had been replaced. Measurements made before, during and after the fluid administration included bodyweight, arterial blood haematocrit, PCO2, pH, standard bicar...
Masri MD, Merritt AM, Gronwall R, Burrows CF.Developmental changes of the gastrointestinal tract were probably responsible for the changes in faecal composition during the first week of the foals' life, which resembled small intestinal ingesta of adult horses, suggesting a minimal colonic modification. Faecal composition at the time of foal heat diarrhoea was suggestive of a secretory-type diarrhoea, in that the electrolyte concentration accounted for most of faecal osmolality and the faecal pH was alkaline. After foal heat diarrhoea faecal composition slowly approached that of adult horses. These data suggest that foal heat diarrhoea is...
Kohn CW, Strasser SL.Urine samples were obtained from 6 healthy mares. During a 2-day acclimation period, mares were kept in stalls, fed sweet feed and mixed grass hay, and allowed free access to water and trace mineral salt. The mares were crosstied in their stalls within reach of hay, salt, and water for 24 hours during which urine was obtained by constant flow via indwelling Foley catheters. Twenty-four-hour urine production was 7,649 to 11,904 ml/day (mean = 9,212 +/- 1,9285) or 14.7 to 25.1 mlĝ/day. (mean = 19.3 +/- 4.1). Urinary excretion and clearance of electrolytes and protein were determined from aliquo...
Huskamp B.Gastroduodenojejunitis is a catarrhal inflammation of the stomach and proximal portion of the small intestine. Secondary overloading of the stomach occurs so that affected horses rapidly enter a state of hypovolaemic shock which is further complicated by the presence of toxins. The condition can occur in a mild or severe form. In mild cases, conservative treatment comprising intravenous electrolyte therapy and repeated gastric decompression is indicated and is usually successful. In severe cases surgical treatment creating duodenocaecal anastomosis has given good results. This should be carrie...
Ungemach FR.Doping in performance horses is defined as the "illegal application of any substance, except normal diet, that might modify the natural and present capacities of the horse at the time of the race." The prohibition of doping is mainly based on the protection of animals. Doping can be performed with various aims: "doping to win" can be regarded as the classical method by mobilization of overphysiological capacities. Such positive doping may be classified as an acute form using psychomotoric stimulants, as a chronic form using anabolic hormones, and as a paradoxical form using small doses of neur...
Morris DD, Divers TJ, Whitlock RH.Four consecutive 6-hour urine collections were obtained from 10 healthy adult horses given free access to a complete pelleted ration and water. Samples of blood were collected from the jugular vein at the start of the test period and then every 6 hours for 4 consecutive samples. Mean renal clearance of creatinine (CCr) varied significantly during the four, 6-hour collections, ranging from 1.474 in period II to 2.702 ml/min/kg of body weight during period III (P less than 0.05). The CCr in period III was significantly different from the 24-hour mean value of 1.877 ml/min/kg (P less than 0.05). ...
Ousey JC, Dudan F, Rossdale PD.The status of the mare and foetus in relation to readiness for birth was assessed by measurement of the electrolytes sodium, potassium and calcium in mammary secretions pre-partum. Sixteen Thoroughbred mares were allowed to foal spontaneously and the ionic status of their mammary secretions was measured over three to five weeks pre-partum. From these measurements, a scoring system was developed where an ionic score of 35 points or more suggested that the mare was within 24 h of foaling. On the basis of this ionic score, 10 pony mares were induced with either oxytocin or fluprostenol and assess...
Seanor JW, Byars TD, Boutcher JK.Renal dysfunction secondary to GI disorders may be relatively common in horses. Persistent dehydration of 8-10% of body weight can lead to prerenal azotemia, which may result in renal ischemia and renal disease if uncorrected. Dehydrated azotemic horses with a urine specific gravity less than 1.018 may have renal disease. Urine specific gravity readings greater than 1.025 usually indicate normal kidney function. A urine Na level less than 20 mEq/L and a urine/plasma creatinine ratio greater than or equal to 20:1 indicate prerenal problems. Use of nephrotoxic drugs should be avoided in septicem...
Tate LP, Ralston SL, Koch CM, Everitt JI.Small intestinal resection (SIR) is not uncommonly done in surgical treatment of equine colic, but little is known about the long-term effects of SIR on horses and ponies. Twelve ponies, fed maintenance amounts of pelleted feed, were divided randomly into 4 treatment groups. D-Xylose absorption curves were recorded for each pony before surgical treatments were performed. Treatments consisted of control (ileal bypass) and 40%, 60%, or 80% SIR. D-Xylose absorption, serum electrolyte, and enzyme profiles for each animal were recorded once every 30 days for 180 days after surgical treatment, and t...
Slone DE, Ganjam VK, Purohit RC, Ravis WR.Six ponies and 1 horse were bilaterally adrenalectomized (BADX). The survival time of 2 of the 7 animals after BADX was 24 and 72 hours without supplemental corticosteroids. The cause of death was not related to the surgical technique. The biological half-life of cortisol (hydrocortisone) was estimated to be 2.1 +/- 0.6 hours. The disappearance of cortisol in the horse was found to be biphasic, composed of redistribution and elimination phases. Pathophysiologic changes (ie, increased serum sodium and chloride, increased PCV, and decreased serum potassium) similar to those seen in other species...
Deldar A, Fregin FG, Bloom JC, Davanipour Z.The effects of strenuous exercise on serum electrolytes, blood metabolites, and serum enzymes were studied in a group of 13 horses participating in a 50-mile endurance ride. Blood samples were collected before, during, and at the end of the ride, as well as 1 hour and 16 hours after the completion of the ride. There were significant changes in these values when preride values were compared with those of samples taken at different sample-collection periods. Significant (P less than 0.001) decreases were observed in serum concentrations of chloride, potassium, and calcium. A significant increase...
Alexander F.The effect of ethacrynic acid, bumetanide, frusemide, spironolactone and anti-diuretic hormone (ADH) on the urinary and faecal excretion of water and electrolytes by ponies was studied. Ethacrynic acid, bumetanide, and frusemide given intravenously, increased urinary sodium excretion, and, excepting frusemide, decreased faecal sodium excretion. Given by stomach tube ethacrynic acid reduced urinary and faecal sodium. Bumetanide, given intravenously, spironolactone, frusemide and ADH increased urinary sodium and all except frusemide intravenously decreased faecal sodium regardless of route of ad...
Clarke LL, Garner HE, Hatfield D.Acute laminitis-hypertension was produced by carbohydrate overloading of the gastrointestinal tract in 12 adult horses. Obel grade 3 (OG3) lameness developed 40 hours (+/- 3.5, SEM) after overfeeding. At OG3 lameness, mean plasma volume was significantly decreased (P less than 0.005) when compared with base-line values. Before OG3 lameness, transient decreases in serum phosphorus and calcium were recorded. Mild hyponatremia also developed before OG3 lameness and persisted. After establishment of OG3 lameness, persistent hypokalemia and increased plasma aldosterone concentration occurred coinci...
Bristol DG.The anion gap was calculated for each of 90 horses with signs of abdominal pain, using laboratory data obtained shortly after admission. The anion gap was defined as the difference between the sodium concentration (mEq/L) and the sum of the chloride and bicarbonate concentrations. To evaluate the use of the anion gap as a prognostic indicator, the survival rates were calculated for horses whose anion gap concentrations were within various ranges. It was found that the probability of survival decreased as the anion gap progressively increased about 20 mEq/L. The survival rates for increasing ra...
Brownlow MA, Hutchins DR.Osmolality is an indication of the osmotic pressure of plasma and depends on the amount of solute and solvent (water) present. The mean (+sd) plasma osmolality of 100 clinically normal animals was 282 (+6) mOsm/kg using lithium heparin as anticoagulant. The equation, osmolality=1.86 (sodium + potassium) +glucose +blood urea nitrogen + 9, was found to predict only crudely plasma osmolality. The plasma sodium: osmolality ratio was 0.49. Water and electrolyte disorders are classified into 3 types based on the measurement of electrolytes and osmolality: (1) Hypertonic dehydration (true dehydration...
Rumbaugh GE, Carlson GP, Harrold D.Total daily 24-hour urinary output was obtained from 11 healthy horses fed alfalfa hay with free access to salt during periods of high environmental temperatures. Daily urinary volume averaged 15.6 L, with mean specific gravity of 1.028, osmolality of 1,040 mOsm/kg, and urinary flow rate of 1.24 ml/kg/hr. Total 24-hour sample collections of urine were also obtained from horses held without access to feed or water for periods of 24, 48, and 72 hours during high environmental temperatures. Average urine production under these conditions was 6.3 L during the 1st day; 3.2 L, the 2nd day; and 3.0 L...
Alexander F.Phenylbutazone administered in therapeutic doses to ponies decreased urinary sodium and chloride excretion. The volume and osmolality of the urine was unaffected as was potassium excretion. Faecal excretion of chloride decreased and that of potassium increased, while faecal sodium excretion was unaffected. Plasma pH, bicarbonate and total carbon dioxide decreased after phenylbutazone administration. Packed cell volume, plasma sodium, potassium, carbon dioxide tension and chloride were unchanged.
Koterba A, Carlson GP.In examination of the acid-base and electrolyte status of 7 horses with acute exertional rhabdomyolysis, the most consistent abnormality was hypochloremia. Metabolic acidosis was not evident in any of the horses. Therefore, the use of sodium bicarbonate in treatment of such disorders may not be indicated in all cases.
Sharp DC, Grubaugh W, Berglund LA, McDowell KJ, Kilmer DM, Peck LS, Seamans KW, Chen CL.The pituitary stalk was transected in 10 Pony mares by a surgical approach that involved dorsal reflection of the brain and micro-dissection from the ventro-lateral aspect of the pituitary. Diabetes insipidus was the most immediate and marked result, requiring extensive electrolyte and antidiuretic therapy for approximately 48 h after operation. Fluid stasis then developed and no further supportive measures were necessary. Endocrine challenge tests with GnRH and TRH before and after stalk transection indicated a loss of responsiveness (GnRH) or suppressed responsiveness (TRH) after the operati...
Schiefer HB.Colitis "X" is a sporadic diarrheal disease of horses with clinical signs of dehydration, electrolyte imbalances and "shock"-like features. Macroscopic and microscopic findings include signs of disseminated intravascular coagulation, necrosis of colonic mucosa and presence of large numbers of bacteria in the devitalized parts of the intestine. Recently published work suggests that the causative agent may be Clostridium perfringens, Type A, but the bacteria are recoverable only in the preliminary stages of the disease. Excess protein and lack of cellulose content in the diet is thought to be th...
Stick JA, Robinson NE, Krehbiel JD.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...
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...
Butudom P, Axiak SM, Nielsen BD, Eberhart SW, Schott HC.Body mass (BM), water intake (WI), and plasma osmolality (P(osm)) and electrolyte concentrations were measured in six 2-year-old Arabian horses provided either 4 l, 8 l, or an unlimited amount of water (UW) for drinking during the initial 5 min of recovery from 45-km of treadmill exercise. After weighing, horses were placed in a stall and further WI between 20 and 60 min of recovery was measured. During exercise, horses lost 3.3+/-0.3%, 3.2+/-0.1%, and 3.3+/-0.2% (P>.05) of BM and P(osm) increased by 7.2+/-0.5, 7.9+/-0.8, and 7.7+/-0.5 mOsm/kg (P>.05) for 4 l, 8 l, and UW, respectively. ...
Harris PA, Marlin DJ, Scott CM, Harris RC, Mills PC, Michell AR, Orme CE, Roberts CA, Schroter RC, Marr CM.Four horses (H, J, N and M) undertook a simulated competition exercise test (CET), designed to simulate physiological and metabolic stresses of the Speed and Endurance (S & E) test of a 3-day-event, under 3 different environmental conditions: 20 degrees C/40% relative humidity (RH) (cool, dry [CD] 2 sessions); 30 degrees C/40% RH (hot, dry [HD]) and 30 degrees C/80% RH (hot, humid [HH]) (Marlin et al. 1995a). Venous blood samples for electrolyte and total protein (TP) determinations were collected from indwelling catheters at predetermined time points throughout each CET and initial 30 min...
Leroux AJ, Schott HC, Hines MT.Ventricular tachycardia was diagnosed in a 12-year-old unconditioned Appaloosa gelding after a 3-day trail ride. Initial signs were those of abdominal discomfort, ileus, and dehydration. Medical treatment included IV administration of lactated Ringer's solution. During hospitalization, the horse developed ventricular tachycardia. Serum potassium concentrations were within reference limits; however, assessment of total body potassium stores was not performed. Resolution of the arrhythmia occurred with further fluid treatment and potassium supplementation. Cardiac arrhythmias should be considere...
Walker WT, Callan RJ, Hill AE, Tisher KB.This study evaluated the effects of administering oral powder electrolytes on packed cell volume (PCV), plasma chemistry parameters, and incidence of colic in horses participating on a 6-day 162-km trail ride in which water was not offered ad libitum. Twenty-three horses received grain with powder electrolytes daily while 19 control horses received grain only. Horses were ridden approximately 32 km a day at a walk or trot. Packed cell volume and plasma chemistry parameters were analyzed daily. Episodes of colic were diagnosed and treated by a veterinarian unaware of treatment group allocation....
Donawick WJ.The horse with an abdominal crisis caused by acute gastro-intestinal tract obstruction develops hypovolaemia, haemoconcentration, electrolyte depletion, metabolic acidosis and shock. During preparation for operation, treatment with fluids, antibiotics and bicarbonate will impede metabolic imbalance. Stomach decompression may slow the passage of sodium, water and potassium to the gut lumen, reduce pain and minimize the risk of stomach rupture. Selected laboratory determinations and the monitoring of arterial and venous pressures will provide a measure of security, and serve as a guide to replac...
Rapp HJ.During the combination of oral and intravenous application of saline solution for treatment of the COPD of horses the level of hydraemia basing on the total protein concentration in the serum, the urine production and the specific weight of urine was determined. Additionally the development of serum concentration and of renal excretion rates of potassium, calcium and magnesium were ascertained. The level of hydraemia resulting from the combined method is almost identical with the solely intravenous performed hyperinfusion therapy. Due to the excessive application of fluid an extremely high lev...
Stampfli HR, Misiaszek S, Lumsden JH, Carlson GP, Heigenhauser GJ.The plasma proteins are a significant contributor to the total weak acid concentration as a net anionic charge. Due to potential species difference, species-specific values must be confirmed for the weak acid anionic concentrations of proteins (Atot) and the effective dissociation constant for plasma weak acids (Ka). We studied the net anion load Atot of equine plasma protein in 10 clinically healthy mature Standardbred horses. A multi-step titration procedure, using a tonometer covering a titration range of PCO2 from 25 to 145 mmHg at 37 degrees C, was applied on the plasma of these 10 horses...
Del Prete C, Lanci A, Cocchia N, Freccero F, Di Maio C, Castagnetti C, Mariella J, Micieli F.Blood collection by indwelling intravenous catheter (IVC) avoids repeated venipuncture, which could cause thrombophlebitis risk, anxiety and pain in patients. Objective: To compare blood gas parameters, electrolytes, glucose, lactate and haematocrit concentration obtained from venous blood samples collected via a jugular IVC by push-pull (PP) technique to those obtained by venipuncture in hospitalised foals, at the time of catheter placement (T0) and 24 hours after the beginning of intravenous therapy (T24). Methods: Prospective observational study. Methods: Paired blood samples were drawn fr...
Alexander F.The effect of ethacrynic acid, bumetanide, frusemide, spironolactone and anti-diuretic hormone (ADH) on the urinary and faecal excretion of water and electrolytes by ponies was studied. Ethacrynic acid, bumetanide, and frusemide given intravenously, increased urinary sodium excretion, and, excepting frusemide, decreased faecal sodium excretion. Given by stomach tube ethacrynic acid reduced urinary and faecal sodium. Bumetanide, given intravenously, spironolactone, frusemide and ADH increased urinary sodium and all except frusemide intravenously decreased faecal sodium regardless of route of ad...
Fielding CL, Deane EL, Major DS, Mayer JR, Love JC, Peralez MS, Magdesian KG.The addition of calcium to resuscitation fluids is a common practice in horses, but studies evaluating the effects of calcium supplementation are limited. In healthy horses, decreases in heart rate and changes in serum electrolyte concentrations have been reported. Objective: Calcium gluconate administration at a rate of 0.4 mg/kg/min to eliminated endurance horses with metabolic problems will affect heart rate, gastrointestinal sounds, and serum electrolyte concentrations. Methods: Endurance horses eliminated from the Tevis Cup 100-mile (160 km) endurance ride for metabolic problems and req...
van Miert AS.A lawyer inquired about the possible harmful effects of 'off-label use' of lincomycin in two trotting horses. From information in the relevant dossier it could be concluded that there was no direct indication to use antibiotics. In addition, mistakes were made in the medicinal treatment of horses, namely, the off-label use of lincomycin without prior consultation with the manufacturer, fluid and electrolyte replacement therapy not continued for long enough, and incorrect use of antipyretic analgesics. The intravenous administration of gentamicin to dehydrated patients is permissible only in co...
Snyder LB, Wendt-Hornickle E.The purpose of this article is to update the community of veterinarians performing general anesthesia in horses on fluid therapy. The rationale behind intraoperative fluid therapy, fluid dynamics, and various fluid options (crystalloids, hypertonic saline, colloids) is discussed. Additionally, electrolytes (calcium, potassium, and sodium) are included in the discussion in relation to general anesthesia and intraoperative fluid management.
Kopper JJ, Bolger ME, Kogan CJ et al. Outcome and complications in horses administered sterile or non-sterile fluids intravenously. J Vet Intern Med 2019; 33: 2739–2745 DIE INTRAVENöSE VERABREICHUNG VON LöSUNGEN DIENT ZUR ERHALTUNG ODER WIEDERHERSTELLUNG DES FLüSSIGKEITSVOLUMENS IN DEN GEFäßEN UND DER GEWEBEDURCHBLUTUNG. SIE IST ENTSCHEIDEND BEI DER BEHANDLUNG VON PFERDEN MIT ERKRANKUNGEN, DIE EINE HYPOVOLäMIE ZUR FOLGE HABEN. ZU DEN TYPISCHEN INDIKATIONEN GEHöREN EIN HOHER GASTROINTESTINALER WASSERVERLUST, EINE EINGESTELLTE WASSERAUFNAHME BZW. EINE NICHT TOLERIERTE ENTERALE FLüSSIGK...
Pawlas-Opiela M, Sołtysiak Z, Gorczykowski M.Gasterophilus sp. constitute a group of specific parasites, which larval forms are found in horses and other phylogenetically related species--donkeys, mules and zebras. Their invasion is associated with marked fluctuations of hematological and biochemical blood parameters, including the activity of many enzymes and the electrolyte concentration. The purpose of the study was to analyze changes in selected biochemical and morphological blood parameters of horses infected with botfly larvae. The experimental group was formed of horses infested by Gasterophilus sp. larvae whereas the control grou...
Annandale CH, Schulman ML, Kirkpatrick RD.Twelve pony mares were randomly assigned to either a control or a treatment group and inseminated with fresh, raw semen from a single stallion of known fertility in a cross-over trial design. Pregnancy was diagnosed by transrectal ultrasound 12-14 days post-ovulation and then terminated by administration of a luteolytic dose of cloprostenol. Treatment mares received a uterine instillation of 100 ml of electrochemically activated (ECA) saline 4-12 hours post-insemination. Control mares received no treatment post-insemination. Per cycle pregnancy rate was 58.3 % in the control group and 50 % in ...
Wellard L, Medyk K, Pearson W.Feed additives that accelerate gastrointestinal transit time may help support normal gastrointestinal function in horses at risk for impaction colic. Previous research has demonstrated significant stimulatory effect of a hemp-based nutraceutical product (Gs Formula; GF) on contractility of gastric smooth muscle and gastrin production in vitro. Objective: To quantify effects of GF on indicators of GIT transit time and tight junction proteins. Methods: Randomized placebo-controlled cross-over study. Methods: Eight Standardbreds were administered 200 plastic beads by nasogastric tube before (base...
Rose RJ, Gibson KT, Suann CJ.Five standardbred geldings were given 1 mg/kg bodyweight of frusemide by intramuscular injection to induce mild dehydration. After food and water deprivation overnight, the mean weight loss was 24.4 +/- 1.8 kg (5.5 per cent of bodyweight). The horses were then given an equivalent volume of an oral glucose-glycine-electrolyte solution by stomach tube. No more than 10 litres was given every 30 minutes until the calculated bodyweight loss had been replaced. Measurements made before, during and after the fluid administration included bodyweight, arterial blood haematocrit, PCO2, pH, standard bicar...
Frape DL.There is no clear evidence that the chronic requirement for any non-energy yielding nutrient rises in proportion as the energy requirement increases with hard work. The need for protein, and probably that for calcium, remain a function of bodyweight daily. Some proportionality with energy may exist for certain nutrients, although the evidence has not been adduced. For example, because of an increase in both the proportion and amount of propionic acid in the volatile fatty acids of caecal contents, the tissue requirement for vitamin B12 may rise with an increase in the rate of energy metabolism...
Tranquilli WJ, Thurmon JC.Several unique pharmacologic and physiologic factors must be considered when attempting to anesthetize premature or neonatal foals. Juvenile foals are similar to adults in their physiology and metabolism. Anesthetic drug and protocol selection should reflect the differences between these two age groups. Neonates are best anesthetized using an inhalation technique, whereas older foals can be safely anesthetized with either parenteral or inhalation anesthetic agents. Careful monitoring is absolutely essential when anesthetizing foals. The clinician should plan to routinely administer fluids and ...
Johnson PJ.This article presents a brief overview of the physiology of homeostasis in the horse and discusses the units of measurement by which dissolved electrolytes are assessed. Differences in electrolyte composition between compartments of the body and the manner in which water is exchanged between them are reviewed. The mechanisms by which alterations in osmolality and effective circulating volume are detected and the physiological responses to those alterations are presented.
Clarke LL, Garner HE, Hatfield D.Acute laminitis-hypertension was produced by carbohydrate overloading of the gastrointestinal tract in 12 adult horses. Obel grade 3 (OG3) lameness developed 40 hours (+/- 3.5, SEM) after overfeeding. At OG3 lameness, mean plasma volume was significantly decreased (P less than 0.005) when compared with base-line values. Before OG3 lameness, transient decreases in serum phosphorus and calcium were recorded. Mild hyponatremia also developed before OG3 lameness and persisted. After establishment of OG3 lameness, persistent hypokalemia and increased plasma aldosterone concentration occurred coinci...
Fielding CL, Magdesian KG.To evaluate changes in electrolyte concentrations and hydration status that take place in endurance horses prior to the start of a competition and determine whether these changes would be associated with elimination. Methods: 19 horses entered in the 2016 Tevis Cup 100-Miles (160 km) One-Day Western States Trail Ride. Methods: Heparinized blood samples were collected at 5 time points: prior to transport to the ride (T0), during check-in the day before the ride (T1), 1 to 2 hours before the start of the ride (T2), at the 15-km mark (T3), and at the 55-km mark (T4). Packed cell volume and plasma...
Rumbaugh GE, Carlson GP, Harrold D.Total daily 24-hour urinary output was obtained from 11 healthy horses fed alfalfa hay with free access to salt during periods of high environmental temperatures. Daily urinary volume averaged 15.6 L, with mean specific gravity of 1.028, osmolality of 1,040 mOsm/kg, and urinary flow rate of 1.24 ml/kg/hr. Total 24-hour sample collections of urine were also obtained from horses held without access to feed or water for periods of 24, 48, and 72 hours during high environmental temperatures. Average urine production under these conditions was 6.3 L during the 1st day; 3.2 L, the 2nd day; and 3.0 L...
Mayhew IG, Ferguson HO.A group of 834 Thoroughbred horses was surveyed on four central Florida farms for clinical and epidemiologic features of anhidrosis. In addition, comparative analysis was made of serum thyroxine, serum electrolytes, and fractional urinary electrolyte excretion ratios. An overall disease prevalence of 6.12% was observed. Training horses and nonpregnant broodmares had a predilection for the disease. Adolescent horses were infrequently affected. There was no correlation with sex or color. Comparative clinical signs, related to thermoregulatory compromise, included tachypnea and hyperthermia. Long...
Many colic horses are compromised due to the disease state and from hours of starvation and sometimes long trailer rides. This could influence their muscle energy reserves and affect the horses' ability to recover. The principal aim was to follow metabolic parameter before, during, and up to 7 days after anaesthesia in healthy horses and in horses undergoing abdominal surgery due to colic. Methods: 20 healthy horses given anaesthesia alone and 20 colic horses subjected to emergency abdominal surgery were anaesthetised for a mean of 228 minutes and 183 minutes respectively. Blood for analysis o...
Marolf V, Mirra A, Fouché N, Navas de Solis C.A 3-day-old Swiss Warmblood colt was diagnosed with uroabdomen after urinary bladder rupture. The foal had classical electrolyte abnormalities (hyponatremia, hypochloremia and hyperkalemia) on presentation. The foal was supported prior to surgery with intravenous fluids and the electrolyte abnormalities were treated with physiologic saline, glucose and insulin. Urine could not be drained from the abdomen prior to surgery because the omentum was continuously occluding the drainage cannula and due to progressive abdominal distension, it was decided to pursue surgery without further correction of...
Canisso IF, Ball BA, Troedsson MH, Silva ES, Davolli GM.The objectives of this study were to determine pH of the mammary gland secretions and the corresponding electrolyte concentrations in prefoaling mares. Pregnant mares (seven primiparous and seven multiparous) were monitored daily from 310-320 days of gestation until parturition. Prefoaling mammary gland secretions were collected, and pH was immediately determined with a pH meter and pH strip test. An aliquot of prefoaling mammary secretions was frozen and stored until further analyses. After parturition, samples from day -4 to 0 (day of foaling) were thawed and electrolyte concentrations (ie, ...
