Metabolic acidosis in horses is a condition characterized by an imbalance in the body's acid-base status, resulting in a lower than normal blood pH. This condition arises when there is an accumulation of acid or a significant loss of bicarbonate in the body, which can occur due to various factors such as intense exercise, gastrointestinal disturbances, or renal dysfunction. In horses, metabolic acidosis can affect cellular function and overall metabolic processes. The condition is typically assessed through blood gas analysis, measuring parameters such as blood pH, bicarbonate levels, and carbon dioxide concentration. This page compiles peer-reviewed research studies and scholarly articles that explore the causes, physiological impacts, and management strategies of metabolic acidosis in equine health.
Carvalho JRG, Sales NAA, Littiere TO, Costa GB, Castro CM, Polisel EEC, Orsi JB, Ramos GV, Santos IFC, Gobatto CA, Manchado-Gobatto FB, Ferraz GC.Several studies have explored alternatives to enhance the performance, health, and safety of sports horses. One promising method involves the use of vibrating platforms (VP), which offer passive exercise stimulation via mechanical oscillations distributed throughout the body. This type of exercise is referred to as whole-body vibration (WBV) and is an emerging strategy for accelerating muscle recovery. This study examined the dynamics of proteins responsible for transporting monocarboxylates (MCT1 and MCT4), and their relationship with lactatemia and acid-base balance in connection with WBV re...
Milner PI, Bardell D.Predicting outcome in horses presenting with colic remains challenging. Objective: To test whether arterial blood samples in horses admitted for colic predict outcome to hospital discharge for different colic types. Methods: Arterial blood samples collected on admission from 358 horses undergoing medical or surgical management of colic were evaluated for pH, PaO, PaCO, Na, K, iCa, Cl, HCO (P), HCO (P, set), Base (B), Base (ecf) and anion gap. Categories were small intestinal non-strangulating (SINS) or strangulating (SIS) lesions, large colon non-volvulus (LCNV) or volvulus (LCV), small colo...
Daradics Z, Bungărdean D, Lupșan AF, Popescu M, Bulmez O, Ciulu-Angelescu V, Chelaru VF, Morar I, Mircean M, Cătoi C, Tripon MA, Crecan CM.Ethylene glycol toxicosis is a common occurrence in dogs and cats but has been reported in other species as well. Up to date, only one case of ethylene glycol toxicosis has been described in horses, and specific guidelines for treating ethylene glycol intoxication in this species are not available. Here we describe the case of 39 sport horses that ingested water contaminated with ethylene glycol. The main clinical sign was apathy, but more severely affected individuals also developed abdominal pain and laminitis. Treatment was initiated around 24 h after the exposure, using ethanol as an antid...
François AC, Renaud B, Kruse CJ, Marcillaud-Pitel C, Votion DM.Anne-Christine François, Benoît Renaud, Caroline-Julia Kruse, Christel Marcillaud-Pitel and Dominique-Marie Votion of the Atypical Myopathy Alert Group discuss insights from 20 years of research and surveillance on equine atypical myopathy.
Loos CMM, Zhao S, Li L, Li J, Han W, Vanzant ES, McLeod KR.The objective of this study was to investigate the effect of essential oil (EO) supplementation on insulin sensitivity (IS) and the plasma metabolome in insulin dysregulated (ID) horses. Horses were blocked by degree of IS and assigned randomly to treatment: oral daily bolus (50 mL) of either a plant derived EO supplement or carrier (CON). Mares were housed in dry lots with access to grass hay and supplemented individually twice daily with a concentrate to meet nutrient requirements for mature horses. Before and after 6 wks of treatment, mares underwent a combined glucose-insulin tolerance ...
Davis MS, Bayly WM, Hansen CM, Barrett MR, Blake CA.The intracellular environment of skeletal muscle can develop pronounced hyperthermia and acidosis during strenuous exercise, and these alterations in the typical intracellular conditions have been shown to alter mitochondrial respiration. However, the impact of these conditions on ATP synthesis is poorly understood. We used Thoroughbred racehorses to test the hypothesis that both hyperthermia and acidosis decrease the rate of ATP synthesis, but that athletic conditioning mitigates this loss of phosphorylation capacity. Isolated mitochondria were harvested from skeletal muscle before and after ...
Brito PHS, Ferreira MA, Rusch E, Arantes JA, Carregaro AB, Valadão CAA, Ghantous GF, Dória RGS.Submitting late-term pregnant mares to anesthesia for non-obstetric surgery raises concerns about the survival of the mother and fetus. This study aimed to evaluate and describe transient maternal and fetal hemodynamic changes during general inhalation anesthesia in mares during the last month of gestation. Nine adult mares in the last month of gestation were subjected to general inhalation anesthesia and dorsal recumbency for 90 minutes. Trans-anesthetic vital parameters, arterial hemogasometry, cardiac output, pulmonary arterial pressure, central venous pressure, and fetal heart rates were a...
Hepworth-Warren KL, Goldsmith D, Tsoi M, Gerras A, Noll C, Pinn-Woodcock T, Moreira A, Penttila K, Ballou ME, Dembek KA, Valberg SJ.To describe the clinical findings, outcomes, and muscle histopathology in warmblood horses that developed severe rhabdomyolysis in the perianesthetic period despite remaining stable while under general anesthesia. Methods: 7 warmblood horses, 6 geldings and 1 mare, with a median age of 9 years (range, 4 to 18 years) and median weight of 615 kg (range, 550 to 703 kg). Records from the Valberg Neuromuscular Diagnostic Laboratory and Michigan State University were reviewed (2016 to 2023) to identify warmbloods with postanesthetic myopathy (PAM). Methods: Warmblood horses with no history of myopat...
Monteiro LC, Costa CM, Ermita PAN, Júnior SJPG, Mattos FS, Mansur FC, Dos Santos MO, Alves SR, Mafort EG, Fidélis CF, Avanza MFB, Teixeira RBC....In adult horses, the development and evaluation of enteral electrolyte solutions containing sodium acetate for correcting hyperchloremic metabolic acidosis are still lacking, although these electrolyte and acid-base imbalances are commonly observed. The objective of this study was to evaluate the alkalinizing effect of two enteral electrolyte solutions containing different concentrations of acetate, administered via nasogastric tube in continuous flow, in adult horses with experimental hyperchloremic metabolic acidosis. Unassigned: Six mares aged between 3 and 10 years were used in a 6×2 cr...
Safaee Firouzabadi MS, Paidar Ardakani A.Many studies have shown a strong correlation between Hindgut Acidosis (HGA) and the occurrence of laminitis in horses; therefore, the early diagnosis of HGA is essential. In this study, we investigated changes in the plasma concentrations of lipopolysaccharide-binding protein (LBP) and serum amyloid A (SAA) as inflammatory markers in horses with laminitis. Sixteen healthy male Arabian horses that had cecal cannulation without visible laminitis or general symptoms were randomly divided into two groups. The horses were fed two different diets in a forage-to-concentrate ratio. Blood samples were ...
Giraldo AF, Carballo R, Serrenho RC, Tran V, Valverde A, Renaud DL, Gomez DE.Metabolic acidosis (MA) is the most common acid-base disorder reported in horses with colitis but its association with survival is yet to be determined. Investigate the types of MA in horses with colitis to determine effects of various anions on fatality rates. We studied 158 horses with colitis. Horses were classified into 4 groups depending on the anion contributing to MA: i) no MA, ii) lactic acidosis (LA), iii) unmeasured strong ion (USI) acidosis, and iv) hyperchloremic acidosis (HA). Sixty percent (95/158) of horses had no MA, 22% (34/158) had LA, 12% (19/158) had HA, and 6% (10/158) had...
Waller AP, Lindinger MI.Oral electrolyte supplementation may influence acid-base state during exercise due to the intestinal absorption of administered water and electrolytes used to mitigating sweat losses. This study examined the effect of pre-exercise electrolyte supplementation (3 and 8 L) on plasma acid-base variables at rest, during moderate intensity exercise and during recovery. It was hypothesized that electrolyte supplementation will result in improved acid-base state compared to the alkalosis typical of prolonged exercise. In randomized crossover fashion, four horses were administered 3 L or 8 L of a hypot...
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: ...
Lindinger MI, Waller AP.The present study determined the independent contributions of temperature, strong ion difference ([SID]), total weak acid concentration ([Atot]) and PCO2 to changes in arterial and mixed venous [H+] and total carbon dioxide concentration ([TCO2]) during 37 min of moderate intensity exercise (~50% of heart rate max) and the first 60 min of recovery. Six horses were fitted with indwelling carotid and pulmonary artery (PA) catheters, had PA temperature measured, and had blood samples withdrawn for immediate analysis of plasma ion and gas concentrations. The increase in core temperature during exe...
Smanik LE, Moser DK, Rothers KP, Hackett ES.Prospective clinical study of blood lactate concentration in horses undergoing colic surgery is needed to determine utility in outcome prediction. Objective: To evaluate venous lactate measurements in horses following colic surgery, including immediately after anesthetic recovery and daily throughout hospitalization, as well as to determine if lactate concentrations were significantly higher in horses that developed postoperative complications or did not survive to hospital discharge. Methods: Horses > 1 year of age undergoing surgery for colic and recovered from general anesthesia were sample...
Mullen KR.This article overviews metabolic disorders associated with renal disease. Included is a discussion of the pathophysiology, clinical signs, and treatment of hyperchloremic metabolic acidosis associated with renal tubular acidosis. Conditions affecting the central nervous system including uremic encephalopathy and hyponatremic encephalopathy secondary to renal disease are presented. Finally, a discussion of the unique features of calcium and phosphorus homeostasis in horses is provided with special emphasis on a recently described syndrome of calcinosis and calciphylaxis of unknown etiology.
Hurcombe SDA, Radcliffe RM, Cook VL, Divers TJ.Hemorrhagic shock in horses may be classified in several ways. Hemorrhage may be considered internal versus external, controlled or uncontrolled, or described based on the severity of hypovolemic shock the patient is experiencing. Regardless of the cause, as the severity of hemorrhage worsens, homeostatic responses are stimulated to ameliorate the systemic and local effects of an oxygen debt. In mild to moderate cases of hemorrhage (<15% blood volume loss), physiological adaptations in the patient may not be clinically apparent. As hemorrhage worsens, often in the uncontrolled situation suc...
Lanier CJ, Taintor JS, Christopherson PW, Spangler EA.Acidemia in sick or injured horses is often due to lactic acid accumulation. Alterations in platelet function and hemostasis are among numerous deleterious effects caused by decreased physiologic pH. Objective: We aimed to evaluate the effect of hyperlactatemia and resultant acidemia on platelet aggregation in equine whole blood using impedance aggregometry. Methods: Platelet aggregation was measured using the Multiplate analyzer in whole blood from 34 healthy horses at baseline and after in vitro addition of lactic acid to adjust the pH. Platelet aggregation of each sample was quantified by t...
Davies J, Thomas C, Rizwan M, Gwenin C.The pH drop in the hindgut of the horse is caused by lactic acid-producing bacteria which are abundant when a horse's feeding regime is excessively carbohydrate rich. This drop in pH below six causes hindgut acidosis and may lead to laminitis. Lactic acid-producing bacteria and have been found to produce high amounts of L-lactate and D-lactate, respectively. Early detection of increased levels of these bacteria could allow the horse owner to tailor the horse's diet to avoid hindgut acidosis and subsequent laminitis. Therefore, 16s ribosomal ribonucleic acid (rRNA) sequences were identified a...
Bernick A, Nieth J, Wehrend A.Uroperitoneum is a typical disease in newborn foals. An accumulation of urine develops in the abdominal cavity in consequence to a congenital or acquired leakage in the urinary tract. Colts are more frequently affected than fillies. The most common cause of uroperitoneum is a rupture of the dorsal urinary bladder wall. The urinary bladder is affected in 73.1 %, the urachus in 21.6 % and the ureter in 5.2 % of cases. Typical clinical signs occur 2-5 days postpartum, and encompass reduced general condition, abdominal distention, mild colic symptoms and unphysiologic micturition. Ultrasou...
Gomez DE, Buczinski S, Darby S, Palmisano M, Beatty SSK, Mackay RJ.Use of different analyzers to measure electrolytes in the same horse can lead to different interpretation of acid-base balance when using the simplified strong ion difference (sSID) approach. Objective: Investigate the level of agreement between 2 analyzers in determining electrolytes concentrations, sSID variables, and acid-base disorders in sick horses. Methods: One hundred twenty-four hospitalized horses. Methods: Retrospective study using paired samples. Electrolytes were measured using a Beckman Coulter AU480 Chemistry analyzer (PBMA) and a Nova Biomedical Stat Profile (WBGA), respectivel...
Arfuso F, Giannetto C, Giudice E, Fazio F, Panzera F, Piccione G.The aim of this study was to assess whether acid-base profile exhibits changes in regularly trained show jumping horses undergoing increasing exercise workloads. Seven female Italian saddle horses were subjected to three different physical exercise trials of increasing workload identified as three exercise phases (EPs). During EPI horses were subjected to a standardized exercise test consisting of 15 minutes of treadmill, during EPII horses were subjected to a show jumping test (height, 0.9-1.1 m; course length, 300 m), during EPIII horses underwent two jumping sessions carried out over two...
Kirsch K, Sandersen C.Early recognition and management of acid-base, fluid, and electrolyte disorders are crucial for the maintenance of health and performance in equine athletes. Objective: To analyze changes in acid-base and electrolyte status associated with exercise during cross-country competitions at different levels using traditional and quantitative approaches. Methods: Thirty-eight eventing horses. Methods: Prospective observational study. Jugular venous blood samples were collected before and after the cross-country test of 25 international eventing competitions ranging from 2-star (formerly 1-star) to 5-...
Kopper JJ, Bolger ME, Kogan CJ, Schott HC.Obtaining commercial fluids for intravenous administration (IVF) was challenging during a recent shortage. This necessitated use of custom-made non-sterile fluids for intravenous administration (JUGs) in some hospitals. There are no studies comparing outcome of horses treated with JUG versus IVF and limited information is available about adverse effects of JUGs. Objective: To evaluate death, complications, blood pH, and plasma electrolyte concentrations of horses that received JUG versus IVFs. Methods: One hundred eighty-six horses that received IVFs and 37 that received JUGs. Methods: A retro...
Melchert M, Aurich C, Aurich J, Gautier C, Nagel C.Stress at foaling has been demonstrated to delay birth. In this study, we followed the hypothesis that even a short delay of foaling increases catecholamine and cortisol release in foals, induces acidosis and impairs neonatal adaptation. Foaling was prolonged for 5 min by transferring mares to an unfamiliar environment at rupture of the allantochorion (group delay, n = 6) while control mares (n = 5) were left undisturbed. In their foals, times from birth to first standing and first suckling, heart rate, heart rate variability (HRV) and salivary cortisol concentration were analysed. B...
Rosenstein PG, Tennent-Brown BS, Hughes D.To review the current literature pertaining to the use of lactate as a prognostic indicator and therapeutic guide, the utility of measuring lactate concentrations in body fluids other than blood or plasma, and the clinical management of hyperlactatemia in dogs, cats, and horses. Methods: Articles were retrieved without date restrictions primarily via PubMed, Scopus, and CAB Abstracts as well as by manual selection. Unassigned: Increased plasma lactate concentrations are associated with increased morbidity and mortality. In populations with high mortality, hyperlactatemia is moderately predicti...
Kimura Y, Aoki T, Chiba A, Nambo Y.Dystocia is often lethal for neonatal foals; however, its clinicopathological features remain largely unknown. We investigated the effect of dystocia on the foal blood profile. Venous blood samples were collected from 35 foals (5 Percheron and 30 crossbreds between Percheron, Belgian, and Breton heavy draft horses) at 0 hr, 1 hr, 12 hr and 1 day after birth. Dystocia was defined as prolonged labor >30 min with strong fetal traction with or without fetal displacement. The dystocia group (n=13) showed lower mean values for pH (P<0.01), bicarbonate (P<0.01), total carbon dioxide (P<0....
Zeyner A, Romanowski K, Vernunft A, Harris P, Müller AM, Wolf C, Kienzle E.The provision of NaCl, according to current recommendations, to horses in moderate work has been shown to induce immediate postprandial acidosis. The present study aimed to clarify whether this NaCl induced acidosis i) persists beyond the immediate postprandial period, and ii) is still present after a 2 week adaptation period. Six adult warmblood mares in moderate work received daily 1.00 kg hay per 100 kg body weight (bwt) only together with 0.64 kg unprocessed cereal grains/100 kg bwt.d as fed basis. Using a 3x3 Latin Square, either 0 (NaCl-0), 50 (NaCl-50) or 100 (NaCl-100) g NaCl/d were fe...
Petersen MB, Tolver A, Husted L, Tølbøll TH, Pihl TH.The objective of this study was to investigate the prognostic value of single and repeated measurements of blood l-lactate (Lac) and ionised calcium (iCa) concentrations, packed cell volume (PCV) and plasma total protein (TP) concentration in horses with acute colitis. A total of 66 adult horses admitted with acute colitis (<24 h) to a referral hospital in the 2002-2011 period were included. The prognostic value of Lac, iCa, PCV and TP recorded at admission and 6 h post admission was analysed with univariate analysis, logistic regression, classification and regression trees, as well as ran...
Viu J, Armengou L, Ríos J, Cesarini C, Jose-Cunilleras E.Acid-base imbalances observed in human paediatric patients are associated with outcome. Likewise, neonatal foals may have different acid-base imbalances associated with diagnosis or prognosis. Objective: To determine acid-base imbalances by the quantitative method in ill neonatal foals and assess their association with diagnosis and prognosis. Methods: Observational prospective clinical study. Methods: This study included 65 ill neonatal foals (32 septic, 33 nonseptic) admitted to an equine referral hospital from 2005 to 2011with acid-base parameters determined on admission and a control group...
Biddle AS, Black SJ, Blanchard JL.Laminitis is a chronic, crippling disease triggered by the sudden influx of dietary starch. Starch reaches the hindgut resulting in enrichment of lactic acid bacteria, lactate accumulation, and acidification of the gut contents. Bacterial products enter the bloodstream and precipitate systemic inflammation. Hindgut lactate levels are normally low because specific bacterial groups convert lactate to short chain fatty acids. Why this mechanism fails when lactate levels rapidly rise, and why some hindgut communities can recover is unknown. Fecal samples from three adult horses eating identical di...
Constable PD.The Henderson-Hasselbalch equation and Stewart's strong ion model are currently used to describe mammalian acid-base equilibria. Anomalies exist when the Henderson-Hasselbalch equation is applied to plasma, whereas the strong ion model does not provide a practical method for determining the total plasma concentration of nonvolatile weak acids ([Atot]) and the effective dissociation constant for plasma weak acids (Ka). A simplified strong ion model, which was developed from the assumption that plasma ions act as strong ions, volatile buffer ions (HCO-3), or nonvolatile buffer ions, indicates th...
Corley KT, Donaldson LL, Furr MO.Blood lactate concentration has been shown to be a useful clinical indicator in human patients, but has not been formally investigated in critically ill foals. Objective: To investigate the association of blood lactate with hospital survival, markers of cardiovascular status, metabolic acid base status, sepsis and systemic inflammatory response syndrome (SIRS). Methods: A database containing clinical, haematological, plasma biochemical and hospital outcome data on neonatal foals referred to an intensive care unit in 2000-2001 was analysed. Seventy-two foals for which arterial lactate was measu...
Bayly WM, Hodgson DR, Schulz DA, Dempsey JA, Gollnick PD.The effects of exercise intensity and duration on blood gases in thoroughbred horses were studied to characterize the apparent exercise-induced failure in pulmonary gas exchange that occurs in these animals. In response to 2 min of exercise, arterial CO2 tension (PaCO2) decreased in mild and moderate exercise, returned to normocapnic levels in moderate to heavy exercise, and rose 5-10 Torr above resting values during very heavy exercise when CO2 production (VCO2) exceeded 20 times the resting value, and mixed venous CO2 tension approximated 140 Torr. Exercise-induced hypoxemia occurred at the ...
Constable PD.The strong ion approach provides a quantitative physicochemical method for describing the mechanism for an acid-base disturbance. The approach requires species-specific values for the total concentration of plasma nonvolatile buffers (A(tot)) and the effective dissociation constant for plasma nonvolatile buffers (K(a)), but these values have not been determined for human plasma. Accordingly, the purpose of this study was to calculate accurate A(tot) and K(a) values using data obtained from in vitro strong ion titration and CO(2) tonometry. The calculated values for A(tot) (24.1 mmol/l) and K(a...
Milner PI, Fairfax TP, Browning JA, Wilkins RJ, Gibson JS.To determine the effects of varying O(2) on pH homeostasis, based on the hypothesis that the function of articular chondrocytes is best understood at realistic O(2) tensions. Methods: Cartilage from equine metacarpophalangeal/tarsophalangeal joints was digested with collagenase to isolate chondrocytes, and then loaded with the pH-sensitive fluorophore 2',7'-bis-2-(carboxyethyl)-5(6)-carboxylfluorescein. The radioisotope(22)Na(+) was used to determine the kinetics of Na(+)/H(+) exchange (NHE) and the activity of the Na(+)/K(+) pump, and ATP levels were assessed with luciferin assays. Levels of ...
Staempfli HR, Townsend HG, Prescott JF.Clinical and hematological changes observed on presentation of 47 horses referred to the Ontario Veterinary College with acute idiopathic colitis were analyzed for their prognostic features. Cases of acute enterocolitis were characterized by fever, dehydration, abnormalities of serum electrolyte concentrations, azotemia, hypoalbuminemia, and increased serum concentrations of muscle enzymes. Severely dehydrated horses were seven times more likely to die or be euthanized than those that were not dehydrated. Other factors associated with failure to survive included the following: increased hemato...
Gomez DE, Arroyo LG, Stämpfli HR, Cruz LE, Oliver OJ.The quantitative effect of strong electrolytes, pCO2 , and plasma protein concentration in determining plasma pH and bicarbonate concentrations can be demonstrated with the physicochemical approach. Plasma anion gap (AG) and strong ion gap (SIG) are used to assess the presence or absence of unmeasured anions. Objective: The physicochemical approach is useful for detection and explanation of acid-base disorders in horses with colitis. AG and SIG accurately predict hyperlactatemia in horses with colitis. Methods: Fifty-four horses with acute colitis and diarrhea. Methods: Retrospective study. Ph...
Moore JN, Owen RR, Lumsden JH.Blood lactate levels were evaluated in 36 horses (43 cases) presented with colic. A correlation between increasing blood lactate levels and decreasing percentage survival has been shown. An appreciable anion gap was found in 7 of 10 cases analyzed in detail but in each case the entire gap could not be accounted for by lactate alone. Proposals are offered to account for the unmeasured anions. Blood lactate determination is suggested as a prognostic rather than a diagnostic aid for the equine practitioner and should be used to augment other clinical findings in the horse exhibiting colic.
Magdesian KG, Hirsh DC, Jang SS, Hansen LM, Madigan JE.To determine molecular characteristics of Clostridium difficile isolates from foals with diarrhea and identify clinical abnormalities in affected foals. Methods: Retrospective study. Methods: 28 foals with C difficile-associated diarrhea. Methods: Toxigenicity, molecular fingerprinting, and antibiotic susceptibility patterns were determined. Information on signalment, clinical findings, results of clinicopathologic testing, whether antimicrobials had been administered prior to development of diarrhea, and outcome was obtained from the medical records. Results: Twenty-three (82%) foals survived...
Le Moyec L, Robert C, Triba MN, Billat VL, Mata X, Schibler L, Barrey E.During long distance endurance races, horses undergo high physiological and metabolic stresses. The adaptation processes involve the modulation of the energetic pathways in order to meet the energy demand. The aims were to evaluate the effects of long endurance exercise on the plasma metabolomic profiles and to investigate the relationships with the individual horse performances. The metabolomic profiles of the horses were analyzed using the non-dedicated methodology, NMR spectroscopy and statistical multivariate analysis. The advantage of this method is to investigate several metabolomic path...
Constable PD, Hinchcliff KW, Muir WW.To compare the accuracy of anion gap (AG) and strong ion gap (SIG) for predicting unmeasured strong ion concentration in plasma and serum from horses. Methods: 6 well-trained Standardbred horses undergoing high-intensity exercise (experimental study) and 78 horses and ponies that underwent i.v. administration of lactic acid or endotoxin, and endurance, submaximal, or high-intensity exercise. Methods: Anion gap was calculated as AG = (Na+ + K+) - (Cl- + HCO3-), and SIG was calculated, using the simplified strong ion model, whereby SIG (mEq/L) = 2.24 x total protein (g/dl)/(1 + 10(6.65-pH)) - AG...
Sernetz M, Gelléri B, Hofmann J.Organisms and bioreactors are open, dissipative systems in steady state. They are functionally equivalent with respect to turnover and kinetics, and structurally analogous with respect to fractal organization and self-similar scaling. As heterogeneous catalytic systems both are governed by interaction of mass transport and reaction. The structural equivalent to turbulence in the reactor, yielding high efficiency, is the fractal folding and branching of the transport systems of the organism. Dimensionally and in terms of fractals, organisms and reactors are therefore area-volume hybrids. The ph...
Bazzano M, Giannetto C, Fazio F, Arfuso F, Giudice E, Piccione G.Pregnancy represents a specific physiological status characterized by continuous adjustments that affect maternal metabolism of all nutrients. In the last trimester of pregnancy, mare's nutrient requirements greatly increase and most pregnancy-associated diseases are likely to occur. Therefore, we aimed to assess the metabolic profile of broodmares focusing on the last 3 months of pregnancy and the early post-partum. Fifteen pregnant mares (Group A) were monitored from 263 ± 3 days of pregnancy until 21 days after foaling. Seven non-pregnant mares (Group B) were used as the control group...
Fielding CL, Magdesian KG, Rhodes DM, Meier CA, Higgins JC.To describe the clinical and clinicopathologic abnormalities in endurance horses eliminated from competition and requiring emergency medical treatment. Methods: Retrospective study over a 2-year period (2005-2006). Ten horses that successfully completed the ride in 2006 were included for comparison. Methods: Temporary equine emergency field hospital. Methods: All horses (n=30) that were removed from endurance competition and treated for a metabolic abnormality were studied. Methods: Horses were treated with IV fluids and analgesics. Monitoring included lab work (PCV, total protein, and electro...
Rosenstein PG, Tennent-Brown BS, Hughes D.To review the current literature pertaining to the use of lactate as a prognostic indicator and therapeutic guide, the utility of measuring lactate concentrations in body fluids other than blood or plasma, and the clinical management of hyperlactatemia in dogs, cats, and horses. Methods: Articles were retrieved without date restrictions primarily via PubMed, Scopus, and CAB Abstracts as well as by manual selection. Unassigned: Increased plasma lactate concentrations are associated with increased morbidity and mortality. In populations with high mortality, hyperlactatemia is moderately predicti...
Gollnick PD, Bertocci LA, Kelso TB, Witt EH, Hodgson DR.The effect of high-intensity exercise on the respiratory capacity of skeletal muscle was studied in horses which ran five 600-m bouts on a track with 2 min of rest between exercise bouts, or once to fatigue on a treadmill at an intensity that elicited the maximal oxygen uptake. Venous blood and biopsy samples of the middle gluteal muscle were collected at rest, after each exercise bout, and 30 and 60 min post-exercise. Blood samples were analyzed for lactate concentration and pH and muscle samples for metabolites, pH, and respiratory capacity. Venous blood and muscle pH declined to 6.91 +/- 0....
Navarro M, Monreal L, Segura D, Armengou L, Añor S.The purpose of this study was to compare traditional and quantitative approaches in analysis of the acid-base and electrolyte imbalances in horses with acute gastrointestinal disorders. Venous blood samples were collected from 115 colic horses, and from 45 control animals. Horses with colic were grouped according to the clinical diagnosis into 4 categories: obstructive, ischemic, inflammatory, and diarrheic problems. Plasma electrolytes, total protein, albumin, pH, pCO2, tCO2, HCO3-, base excess, anion gap, measured strong ion difference (SIDm), nonvolatile weak buffers (A(tot)), and strong io...
Viu J, Jose-Cunilleras E, Armengou L, Cesarini C, Tarancón I, Rios J, Monreal L.Acid-base disturbances are traditionally assessed using the Henderson-Hasselbach equation. The simplified strong ion approach describes more accurately the complex acid-base and electrolyte abnormalities present in endurance horses. Objective: To describe acid-base and electrolytes changes in fit horses competing in a FEI*** 120 km endurance race and to compare the traditional vs. strong ion approaches. Methods: Thirty horses were initially enrolled in the study. Venous blood samples were obtained before the race (n = 25), at the second (n = 29; 65.4 km) and third vet-gates (n = 23, 97.4 km) a...
Tennent-Brown B.Admission blood lactate concentration is widely used as a prognostic indicator in equine medicine and can be a useful indicator of disease severity but typically fails to completely discriminate survivors from nonsurvivors. Increased admission lactate concentrations in adult horses typically return to normal within 12 to 24 hours. Lactate concentrations in neonatal foals are higher than adult concentrations for the first 24 to 72 hours of life. Serial measures reflecting both the magnitude and duration of hyperlactatemia might enable more accurate prognostication and provide insight into dis...
Rose RJ, Ilkiw JE, Martin IC.The effects of prolonged strenuous exercise on arterial and venous oxygen tension, carbon dioxide tension, pH, bicarbonate, standard bicarbonate, base excess, haemoglobin, packed cell volume and total plasma protein were studied in 36 horses during a 100 km endurance ride. There were significant changes in many parameters when pre-ride values were compared with both mid-ride and end of ride values. The prominent changes were the development of dehydration and a metabolic alkalosis. At the mid-ride sampling time those horses with higher heart rates had a greater degree of metabolic alkalosis th...
Petersen MB, Tolver A, Husted L, Tølbøll TH, Pihl TH.The objective of this study was to investigate the prognostic value of single and repeated measurements of blood l-lactate (Lac) and ionised calcium (iCa) concentrations, packed cell volume (PCV) and plasma total protein (TP) concentration in horses with acute colitis. A total of 66 adult horses admitted with acute colitis (<24 h) to a referral hospital in the 2002-2011 period were included. The prognostic value of Lac, iCa, PCV and TP recorded at admission and 6 h post admission was analysed with univariate analysis, logistic regression, classification and regression trees, as well as ran...
Gossett KA, Cleghorn B, Adams R, Church GE, McCoy DJ, Carakostas MC, Flory W.Increased anion gap (AG) was due, in part, to L-lactic acidosis in 14 of 14 horses with intestinal disorders. In a few horses, increased whole blood concentrations of D-lactate made a minor contribution to the AG. However, the increase in AG was often greater than the sum of the increases in these 2 acid anions. This unexplained increase was not a result of increases in whole blood pyruvate, 3-hydroxybutyrate, or acetoacetate concentrations or serum albumin or phosphate concentrations. Identification of other anions causing increased AG could lead to better understanding, diagnosis, and treatm...
Borchers A, Magdesian KG, Halland S, Pusterla N, Wilson WD.Tyzzer's disease is a rapidly progressive and highly fatal hepatitis of foals caused by Clostridium piliforme. Survival of a confirmed case has not been reported previously. Objective: Successful therapy of C. piliforme infection in foals is possible. Polymerase chain reaction (PCR) can be used to diagnose Tyzzer's disease antemortem or postmortem. Methods: Seven foals were included in the study. Methods: Retrospective study was made to evaluate the clinical and pathologic characteristics of foals with Tyzzer's disease. Medical records of the Veterinary Medical Teaching Hospital at University ...
Rose RJ, Sampson D.Total and individual non-esterified fatty acids (NEFA), pyruvate, lactate, alpha ketoglutarate, acetoacetate, beta hydroxybutyrate, glucose and insulin were measured in horses during an 80 km endurance ride and during four days of food deprivation. In the latter group venous blood-gas and acid-base parameters, and plasma cortisol concentrations were also measured. During exercise and food deprivation the NEFA became considerably elevated, the predominant of which were oleic (35 per cent), palmitic (24 per cent), linoleic (19 per cent) and linolenic (10 per cent). By one hour after feeding tota...
Grosche A, Morton AJ, Graham AS, Polyak MM, Freeman DE.To determine the effect of large colon ischemia and reperfusion on concentrations of the inflammatory neutrophilic protein calprotectin and other clinicopathologic variables in jugular and colonic venous blood in horses. Methods: 6 healthy horses. Methods: Horses were anesthetized, and ischemia was induced for 1 hour followed by 4 hours of reperfusion in a segment of the pelvic flexure of the large colon. Blood samples were obtained before anesthesia, before induction of ischemia, 1 hour after the start of ischemia, and 1, 2, and 4 hours after the start of reperfusion from jugular veins and ve...
Stämpfli HR, Schoster A, Constable PD.Profiles from serum biochemical analyzers include the concentration of strong electrolytes (including l-lactate), total carbon dioxide (tCO2 ), and total protein. These variables are associated with changes in acid-base balance. Application of physicochemical principles may allow predicting acid-base balance from serum biochemistry without measuring whole blood pH and pCO2 . Objective: The purpose of the study was to determine if the acid-base status of critically ill horses could be accurately predicted using variables included in standard serum biochemical profiles. Methods: Two jugular veno...
Tennent-Brown BS.In hospitalized horses, hypovolemia and the resulting decrease in tissue perfusion is the most common cause of hyperlactatemia. Therefore, measurement of blood lactate concentration can be a useful tool for guiding fluid therapy. Similarly, measuring blood lactate concentration can be used to assess the need for and adequacy of transfusions in horses receiving whole blood. Inflammatory leukocytes within closed body cavities consume glucose and produce lactate. Simultaneous measurement of blood lactate concentration and lactate concentration of peritoneal, pleural, or synovial fluid has been us...
