Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Potassium
Potassium is an essential mineral and electrolyte that is vital for various physiological processes in horses. It is involved in maintaining cellular function, fluid balance, and nerve signal transmission. Potassium is predominantly stored within the cells and plays a role in muscle contraction and heart function. The dietary intake of potassium is primarily through forage, and its balance is regulated by the kidneys. Abnormal potassium levels can lead to health issues such as muscle weakness or cardiac disturbances. This page compiles peer-reviewed research studies and scholarly articles that explore the role, regulation, dietary sources, and clinical implications of potassium in equine health.
Restoration of water and electrolyte balance in horses after repeated exercise in hot and humid conditions. Nine adult riding horses performed on a treadmill a competition exercise test (CET) and 24 h later a standardised exercise test (SET) at mean temperature 28 degrees C and relative humidity 58%. Each horse performed the tests 5 times at 2 week intervals. The horses were given isotonic glucose-electrolyte solution via a nasogastric tube 30 min after the CET, except after the last trial when water was given. Blood lactate, plasma concentration of aldosterone, arginine vasopressin, protein, sodium, potassium, chloride, magnesium and calcium were measured. Heart rate at blood lactate concentration ...
Biochemical changes in three-day-event horses at the beginning, middle and end of Phase C and after Phase D. Blood samples were collected 12-16 h before the Speed and Endurance test, immediately after steeplechase, midway through Phase C (4 km marker), at the end of Phase C and immediately after cross-country from 36 horses that completed a 3-day-event at the CCI* (n = 19) or CCI** (n = 17) level. Packed cell volume (PCV), plasma concentrations of sodium, potassium, chloride, ionized calcium, pH and lactate; and serum concentrations of total protein (TP), albumin, total calcium, alkaline phosphatase (AP), gamma glutamyl transferase (GGT), creatine kinase (CK), aspartate aminotransferase (AST), glucos...
Elemental composition of muscle at rest and potassium levels in muscle, plasma and sweat of horses exercising at 20 degrees C and 35 degrees C. In this study, 4 Standardbred geldings were exercised at 20 and 35 degrees C. The exercise test (ET) consisted of 2 exercise bouts separated by 2 h of rest in their boxes. Blood samples were taken before, during and after the second exercise bout and muscle (m. gluteus medius) biopsies were taken before the first exercise bout and after an intensive trot over 2600 m in the second exercise bout. The blood samples were analysed for plasma potassium and total plasma protein concentration (TPP) and the muscle fibres were analysed for elemental composition by x-ray microanalysis. The intracellular ...
Sweat fluid and ion losses in horses during training and competition in cool vs. hot ambient conditions: implications for ion supplementation. The objectives of this study were to: 1) determine incremental and total sweat fluid and ion losses during and following (a) exercise training and (b) a treadmill Speed and Endurance exercise test (SEET) which simulated running speeds and distances required for each phase of an Olympic level (CCI****) 3-day-event in cool and hot ambient conditions and 2) determine the requirement for ion supplementation based on the calculated ion losses associated with these activities. Six exercise-trained Thoroughbred horses completed 2 weeks of exercise training in each of 2 ambient conditions: cool, dry (...
Acid-base and electrolyte effects of shortening steeplechase in a three-day-event. This study was designed to characterise the acid-base and electrolyte effects of shortening the distance required during steeplechase (Phase B) in the face of hot and humid weather conditions during a treadmill-simulated Speed and Endurance test. Eight conditioned Thoroughbred horses underwent 3 randomised permutations of a standardised exercise test on a high speed treadmill. Each test consisted of trotting at 3.7 m/s for 10 min (Phase A); galloping at 11 m/s (Phase B) for 4 (cool laboratory conditions), 3 (hot and humid), or 2 (hot and humid) min; trotting at 3.7 m/s for 30 min (Phase C); an...
Hyperkalemic periodic paralysis episode during halothane anesthesia in a horse. A 7-month-old Quarter Horse filly was admitted for surgical repair of a right olecranon fracture. Anesthesia was achieved with xylazine hydrochloride, guaifenesin, ketamine hydrochloride, and halothane. Two and a half hours after induction of anesthesia, myotonia, muscle fasciculations, and sweating, concurrent with high serum potassium concentration and associated electrocardiographic changes consistent with hyperkalemic periodic paralysis, were observed. Treatment included intermittent positive-pressure ventilation, changing intravenous administration of fluids from lactated Ringer's solutio...
The effects of oxygenation upon the Cl-dependent K flux pathway in equine red cells. The effects of oxygen tension (PO2) upon the K influx pathways of equine red cells have been studied using 86Rb+ as congener for K. Equilibration of cells in 100% nitrogen led to a low and Cl-independent K flux. Change to an atmosphere of 100% air led to a rapid sixfold increase in K flux. The oxygen-activated flux was entirely Cl dependent and was maintained for up to 3 h. Oxygenation-evoked activation was dependent upon PO2 over the physiological range with little effect up to 70% saturation of haemoglobin with oxygen but significant effects between 70 and 100%. K flux at low PO2 was unaffec...
Effects of furosemide on hemorheologic alterations induced by incremental treadmill exercise in thoroughbreds. To determine whether furosemide treatment altered the blood flow properties and serum and RBC electrolyte concentrations of Thoroughbreds during submaximal treadmill exercise. Methods: Thoroughbreds were subjected to submaximal treadmill exercise with and without treatment with furosemide (1 mg/kg of body weight, IV). Methods: 5 healthy Throughbreds that had raced within the past year and had no history of exercise-induced pulmonary hemorrhage. Methods: Venous blood samples were obtained before exercise, at treadmill speeds of 9 and 13 m/s, and 10 minutes after exercise, and hemorheologic and ...
[Kidney function tests in horses–methods and reference values in healthy animals]. Investigations of renal function have been done on the basis of renal clearance (Clr) and excretion (E) of endogenous creatinine in healthy horses of different body weight (23 female, 7 male). Creatinine was measured by enzymatic PAP-method. Creatinine-E of female horses was poor positively correlated with body weight. The creatinine-Clr was highly correlated with the inulin-Clr (r = 0,896, p < 0,001). The excretion of creatinine was 35% higher than the filtration of creatinine, determined by inulin-Clr. That demonstrate a tubular net secretion of 26% of the total creatinine excretion. However...
Detection of non-steroidal anti-inflammatory drugs in equine plasma and urine by gas chromatography-mass spectrometry. A gas chromatographic-mass spectrometric (GC-MS) procedure for the detection of seventeen non-steroidal anti-inflammatory drugs (NSAIDs) in equine plasma and urine samples is described. The extraction of the compounds from the biological matrix was performed at acidic pH (2-3) with diethyl ether. Ethereal extracts were washed with a saturated solution of sodium hydrogencarbonate (urine) or treated with a solid mixture of sodium carbonate and sodium hydrogencarbonate (plasma). The ethereal extracts were dried and derivatized by incubation at 60 degrees C with methyl iodide in acetone in the pre...
Osmolality of equine blastocyst fluid from day 11 to day 25 of pregnancy. Horse conceptuses collected between Day 11 and Day 18 of pregnancy float in isotonic media. To investigate this phenomenon, blastocyst fluids from 30 conceptuses from 13 mares were analysed for osmolality and for concentrations of Na+, Cl-, K+, glucose, urea and creatinine. In conceptuses from Group A, samples from Day 11 to Day 16 yielded the following results (mean +/- s.e.m.): osmolality, 121.4 +/- 1.5 mOsm kg-1; Na+, 11.0 +/- 2.2 mM; Cl-, 29.3 +/- 2.5 mM; K+, 26.2 +/- 2.6 mM; glucose, 0.6 +/- 0.1 mM; urea, 6.0 +/- 0.6 mM; creatinine, 9.6 +/- 1.1 microM. Between Day 16 and Day 25, the osmol...
Involvement of nitric oxide in the non-adrenergic non-cholinergic neurotransmission of horse deep penile arteries: role of charybdotoxin-sensitive K(+)-channels. 1. The involvement of nitric oxide (NO) and the signal transduction mechanisms mediating neurogenic relaxations were investigated in deep intracavernous penile arteries with an internal lumen diameter of 600-900 microns, isolated from the corpus cavernosum of young horses. 2. The presence of nitric oxide synthase (NOS)-positive nerves was examined in cross and longitudinal sections of isolated penile arteries processed for NADPH-diaphorase (NADPH-d) histochemistry. NADPH-d-positive nerve fibres were observed in the adventitia-media junction of deep penile arteries and in relation to the trabec...
Electrolyte and total protein changes in nonheat acclimated horses performing treadmill exercise in cool (20 degrees C/40%RH), hot, dry (30 degrees C/40%RH) or hot, humid (30 degrees C/80%RH) conditions. 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...
Sweating rate and sweat composition during exercise and recovery in ambient heat and humidity. The objective of this study was to determine the composition and extent of sweat losses during submaximal exercise under hot and humid conditions and to compare these findings with the same exercise protocol conducted under cool, dry and hot, dry conditions. Five Thoroughbred horses (age 3 to 6) completed exercise tests under each of 3 environmental conditions in random order: cool, dry (CD), room temperature (T) = 20 degrees C, relative humidity (RH) = 45-55%; hot, dry (HD), T = 32-34 degrees C, RH = 45-55%; and hot, humid (HH), T = 32-34 degrees C, RH = 80-85%. Horses exercised at 50% of the...
Haematological and biochemical changes in horses competing in a 3 Star horse trial and 3-day-event. Haematological and biochemical changes in horses competing in the Endurance Test (Phase T and D) of an advanced Horse Trial (HT, n = 22) and the Endurance Test (Phases A-D) of an advanced (CCI) 3-day-event (TD, n = 11) over a similar course on the same day were studied. Environmental conditions during the event were cool (5.5-11.1 degrees C). Blood samples were collected from the horses in each group the evening prior to the Endurance Test, within 60 s after, and 10 min after, completion of Phase D (cross-country jumping). The following were determined in the blood samples and compared between...
The effect of ambient temperature and saline loading on changes in plasma and urine electrolytes (Na+ and K+) following exercise. In this study 4 Standardbred geldings (age 3-8 years, weight 431-531 kg) were used. The horses were fed a hay and oat diet and the total sodium intake was about 32 mg/kg bwt (690 mmol/day). An exercise test (ET) which contained 3 phases was performed. Phase I consisted of 23.5 min of mainly submaximal exercise, Phase 2 of 2 h of box rest and Phase 3 of 26 min of exercise including an intensive trot over 2600 m at 90% of VO2max. The ET was repeated 3 times: the first at 20 degrees C (30-40% RH), the second at 35 degrees C (30-40% RH) and the third at 35 degrees C (30-40% RH) after a nasogastric...
Equine sweat composition: effects of adrenaline infusion, exercise and training. Significant alterations in plasma electrolyte concentrations have been reported in horses following prolonged exercise, resulting from loss of hypertonic sweat. Sweat was collected from 10 horses undergoing a 10 week training programme; 5 at moderate intensity, to speeds of 10 m/s and 5 at low intensity, to speeds of 5 m/s. Sweat was collected from 2 sites in response to a submaximal exercise test (30 min at 50% VO2max and during an adrenaline infusion (dose mean +/- s.d.; 0.3 +/- 0.05 g/kg over 30 min). Sweat samples were analysed for sodium, chloride, potassium, protein, magnesium, calcium a...
Water and ion losses during the cross-country phase of eventing. Loss of total body water and ions during prolonged exercise can predispose the horse to health and performance problems. This study examined total body water (TBW) losses and extracellular (ECF) ion losses during the cross-country (XC) phase of Preliminary, Intermediate and Advanced Horse Trials and CCI level 3-day-events. Jugular venous blood samples and body mass (BM) were collected on 49 horses at rest, Pre-XC, Post-XC and following 30 min of recovery. Plasma was separated from blood cells within 10 min of collection. Plasma was analysed for [Na+], [K+], [Cl-], ionised [Ca+2], [glucose], [l...
Plasma volume and ions during exercise in cool, dry; hot, dry; and hot, humid conditions. We studied the effects of heat and relative humidity (RH) on plasma volume (PV) and ion responses to submaximal exercise and 60 min recovery in Thoroughbreds. Five horses were exercised at 50% of peak VO2 in cool, dry (CD, T = 22 degrees C, RH = 45-55%), and hot, humid (HH, T = 30-34 degrees C, RH = 80-85%) conditions until a pulmonary artery temperature of 41.5 degrees C was reached. Blood was obtained from the carotid artery. Body mass was measured at rest and after 30 min of recovery. The thermal conditions had no effect on the PV and ion responses during exercise and initial 30 min of reco...
Hematological changes observed in Andalusian horses with laminitis. Clinical blood chemistry was studied on 13 Andalusian horses with laminitis. Ten healthy horses were used as controls. Blood samples were taken within the first 24 hr after the onset of the disease in Obel grade 3 before any type of treatment was given. No significant differences were observed in the number of red blood cells and white blood cells between Andalusian horses affected by laminitis and healthy animals. Significant decrease in the number of neutrophils and increased number of lymphocytes were noted. A significant increase in the enzymatic activity of CPK, LDH and AST in these anima...
Prophylactic efficacy of phenytoin, acetazolamide and hydrochlorothiazide in horses with hyperkalaemic periodic paralysis. Horses with hyperkalaemic periodic paralysis were challenged with an oral dose of potassium chloride, and the prophylactic efficacy of phenytoin, acetazolamide and hydrochlorothiazide was evaluated, with at least three weeks separating the trials of each drug. After the administration of potassium chloride without prophylactic medication the horses' clinical signs ranged from generalised fine muscle fasciculations to gross tremors, and weakness with occassional prolapse of the nictitating membrane; plasma potassium concentration increased significantly (P < 0.01) from 4.0 +/- 0.2 to 6.0 +/-...
Indwelling cecal catheters for fluid administration in ponies. Two different fluid solutions were infused through percutaneous cecal catheters in 6 healthy ponies to determine the effects on body weight; CBC; packed cell volume (PCV); total plasma protein concentration; plasma fibrinogen concentration; abdominal fluid analysis; concentrations of blood urea nitrogen (BUN), serum creatinine, Ca, total CO2 (TCO2), Na, Cl, K, and P; and fractional clearance (FC) of Na, Cl, K, and P. During intracecal administration of solution 1, FCNa and FCCl were significantly increased, whereas FCK and BUN were significantly decreased. During administration of solution 2, ...
Ventricular tachycardia associated with exhaustive exercise in a horse. 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...
Hyperkalaemic periodic paralysis in Australian quarter horses. Three Quarter Horse stallions and 5 of their 11 tested progeny were diagnosed as affected with the inherited autosomal dominant defect hyperkalaemic periodic paralysis in Victoria in 1992. The diagnoses were based on the appearance of clinical signs and associated increased plasma potassium concentrations in response to oral potassium loading. All affected horses were descendants of the American Quarter Horse Impressive. Indirect evidence indicates that at least 3 other affected Quarter Horse stallions have stood or are standing at stud in Australia. The clinical details of the affected horses...
Acid-base variables during incremental exercise in sprint-trained horses fed a high-fat diet. 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,...
Effect of phenytoin on skeletal muscle from quarter horses with hyperkalaemic periodic paralysis. The contractile activity, the threshold for calcium-induced calcium release in fractions of sarcoplasmic reticulum and the potassium concentration were determined in preparations of semimembranosus muscle from normal quarter horses and quarter horses with hyperkalaemic periodic paralysis before and after they were treated with phenytoin. Before the treatment there was no difference in caffeine contracture or electrically elicited twitch response between the two groups. For one week after the treatment, the time to peak tension of caffeine contractures was significantly (P < 0.005) reduced i...
Comparative treatment of mares susceptible to chronic uterine infection. Four intrauterine treatment strategies were evaluated for effectiveness in mares that were confirmed to be susceptible to chronic uterine infection. Pretreatment samples were obtained at detection of estrus, and a genital strain of Streptococcus zooepidemicus was infused into the uterus when a preovulatory (> 35 mm) follicle was detected. At 12 hours after inoculation, mares were assigned to 1 of 4 selected treatment groups: autologous plasma, 100 ml (n = 5); potassium penicillin, 5 million U in 100 ml of phosphate-buffered saline solution (PBSS; n = 5); 10 mg of prostaglandin F2 alpha in 1...
Voltage-gated ion channelopathies: inherited disorders caused by abnormal sodium, chloride, and calcium regulation in skeletal muscle. The pathological genetic defects in the inherited myotonias and periodic paralyses were recently elucidated using molecular genetic studies. These disorders are usually transmitted as a dominant trait from an affected parent to a child. The many clinical symptoms include cold-induced uncontrollable contraction of muscle, potassium-induced contraction and paralysis, myotonia with dramatic muscular hypertrophy, muscle stiffness, and insulin-induced paralysis (in males). Horses afflicted with the disorder can suddenly collapse, despite an impressive physique. In the past three years, these clinic...
[Renal tubular acidosis (type 2) in a Friesian mare]. A 2-year-old Friesian mare was examined because she had been sluggish for a few weeks. Blood biochemistry showed that concentrations of creatinine (136 mumol.L-1) and urea nitrogen (6.1 mmol.L-1) in plasma were within their normal limits. Severe metabolic acidosis was apparent; the venous pH was 7.154 and the bicarbonate concentration was 13 mmol.L-1. The base excess amounted to -15.3 mmol.L-1 and the venous pCO2 measured 5.1 kPa. Plasma sodium was normal (135 mmol.L-1) and plasma chloride (113 mmol.L-1) was slightly elevated, but there was a hypokalaemia (2.9 mmol.L-1). The urine had a specif...
Modulation of K(+)-Cl- cotransport in equine red blood cells. Potassium transport was measured in equine red blood cells, using 86Rb+ influx as a convenient assay. A significant component of volume- and pH-sensitive K(+)-Cl- cotransport to the overall K+ flux was observed in all blood samples studied, although fluxes were variable between animals, and within individuals when measured at intervals over a period of weeks. The aryloxyacetic acid [(dihydroindenyl)oxy]alkanoic acid (DIOA), at a final concentration of 100 microM, inhibited most (> 95%) of the Cl(-)-dependent K+ flux, and DIOA sensitivity was therefore used to define the activity of the K(+)...
