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.
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...
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.
Rose RJ, Rossdale PD, Leadon DP.Six spontaneously delivered foals, 8 Thoroughbred foals induced at term with fluprostenol and 17 Pony foals induced prematurely with fluprostenol and oxytocin at a gestational age of 270 to 330 days were studied to determine PO2, PCO2, pH, base excess and HCO3 values in arterial blood between birth and 7 days of age. The Pony foals were subdivided into those that survived greater than 24 h (N = 9) and less than 9 h (N = 8). Blood gas and acid base values in the term-induced foals were similar to those in spontaneously delivered foals. The induced premature foals surviving greater than 24 h had...
Fessler JF, Bottoms GD, Roesel OF, Moore AB, Frauenfelder HC, Boon GD.A study was made of flunixin meglumine (FM), an analgesic agent with antiprostaglandin activity, in the management of endotoxin-induced changes in ponies. Three groups of 5 ponies each were used: A--controls, B--nontreated ponies with endotoxin-induced shock, and C--ponies with endotoxin-induced shock treated with FM. Shock was induced in anesthetized ponies with IV injections of Escherichia coli endotoxin. Disruption of glucose homeostasis, insulin levels, hemograms, aerobic metabolism, and cell damage as indicated by plasma enzymes were observed. Treatment with FM (5 minutes) after shock was...
Littlejohn A, Bowles F.The haemoglobin concentration, the partial pressures of oxygen and carbon dioxide, the oxygen content and the pH were determined in the arterial and mixed venous blood of 5 normal and 3 horses with chronic obstructive pulmonary disease (COPD) at 3 stages of an exercise distance of 1200 m. Arterial and mixed venous samples were collected simultaneously by means of an automatic technique during the walk, trot and gallop at 0-100 m, at 500-600 m and at 1100-1200 m. The standard bicarbonate and the lactic and pyruvic acid concentrations were also determined in arterial and mixed venous blood. High...
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...
Arnbjerg J.Peroral application of iron salts in various types of anemia was previously considered atoxic. The increased use of iron has, however, led to an increasing number of poisoning in children, taking iron tablets for candy. There have only been reported a few number of spontaneous intoxications in animals, but experimentally it has been possible to produce fatal intoxications in various kinds of animal species. The clinical findings are quite similar in the various animals, starting with vomiting, bloody diarrhoea and metabolic acidosis. If the intoxication is severe, shock and coma may develop, a...
Rose RJ.In this article a physiological approach to fluid therapy is discussed, commencing with examination of fluid distribution in the normal horse. The functions of individual plasma electrolyte concentrations are considered and practical causes of acid-base disturbances discussed. When fluid administration is necessary, selection of the route for fluid administration as well as the type of fluid are important considerations and these must be adjusted to the needs of the individual case. Balanced polyionic solutions appear to be most suitable for general use because normal saline can produce hypoka...
Moore JN, Garner HE, Shapland JE, Hatfield DG.Effects of a sublethal IV dose (10 micrograms/kg of body weight) of Escherichia coli endotoxin were studied in 7 conscious ponies. Arterial blood gases and plasma lactic acid were determined periodically throughout the 180 minutes of the study. Arterial hypoxemia occurred within 5 minutes despite intense hyperventilation. Colic and diarrhea occurred in all ponies within 30 minutes after endotoxin administration. Metabolic acidosis developed within 30 minutes and persisted throughout the study, indicating widespread reduced tissue perfusion.
Rose RJ, Ilkiw JE, Sampson D, Backhouse JW.Sixteen horses competing in a three-day event had venous blood samples collected during the speed and endurance test (day 2) to examine changes in blood gas ands acid-base balance, and the concentrations of lactate, pyruvate, beta-hydroxybutyrate, acetoacetate, alpha-ketoglutarate and cortisol. Following the roads and tracks and steeplechase phases there was a significant metabolic and respiratory alkalosis despite a rise in lactate. After completion of the cross country section, although there was a significant decrease in total base, there was no significant change in pH from pre-event value...
Hjortkjaer RK, Svendsen CK.Experimental closed loop small intestinal volvulus was studied in the anesthetized horse. Volvulus was simulated by ligation of the mesenterial veins to a segment of small intestine. Physical signs and hemodynamic, hematologic, clinical chemical, bacteriologic and peritoneal fluid values were examined. Compared to conscious horses anesthesia highly delayed and modified the clinical signs of shock (changes in mucosal colour, dehydration, decreased skin temperature, elevated pulse rate, low blood pressures) and of small intestinal volvulus (altered peristalsis, gastric dilation). Plasma glucose ...
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...
Assal AN, Poulsen JS.The changes in pH, pCO2, pO2, BE, SBC, and lactic during storage of equine venous and arterial blood in 24 hours at different temperatures were measured (tables I, II), and illustrated (fig, 1, 2, 3). Correction tables (tables VI, VII) for determination of the initial acid-base data are constructed based on regression equations (tables IV, V) of the in vitro changes of the blood. The changes in the acid-base values of equine blood differ from that of bovine and canine blood (table III).
Harkema JR, Robinson NE, Scott JB.Twelve Shetland ponies were fed a high-starch ration. Seven ponies which had a transitory metabolic acidosis developed laminitis 56 hours (+/- 3.5, SEM) after overfeeding. These ponies also developed persistent hypokalemia, hyperthermia, and increased heart rate 24 hours before the onset of lameness. Serum sodium, serum chloride, hematocrit, plasma volume, and blood volume were unchanged. At the onset of clinical signs of laminitis, cardiac output and blood pressure increased, but total peripheral resistance was unchanged. None of the measured or calculated values predicted the onset of lamini...
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.
Krzywanek H, Milne DW, Gabel AA, Smith LG.Blood gases, lactic acid concentrations, and pH were measured in arterial and mixed venous blood in moderately conditioned Standardbred horses after a standardized exercise load of 1.6 km in 2 minutes, 40 seconds. Samples were obtained at rest, immediately after exercise, and at 3, 6, 15, 30, and 60 minutes after exercise. Arterial oxygen tension and mixed venous oxygen tension increased after exercise, reaching peak values at 6 minutes. Arterial oxygen tension returned to the resting (preexercise) value by 15 minutes, and mixed venous oxygen tension by 30 minutes. Arterial carbon dioxide tens...
Komárek J, Stros K, Sýkora I, Kynclová I, Jadrný L, Selinger P.By means of the Astrup equilibration method the values of the acid-base balance of the blood were determined in 104 cows, 99 horses, 100 pigs, 15 sheep, 20 goats, and in 101 dogs. The pH values of the blood, the partial pressure of CO2, the base excess, the base buffer, the standard bicarbonate, the actual bicarbonate, and the total CO2 were processed statistically and are presented in tables.
Hillidge CJ, Lees P.Respiratory function and acid-base variables were studied in Welsh Mountain ponies before and at predetermined times after the intravenous injection of Immobilon and Revivon.A marked depression of respiratory rate was accompanied by large reductions in arterial blood oxygen tension and saturation and the development of a mild respiratory acidosis following the injection of Immobilon. It was concluded that at least three factors contributed to the hypoxic hypoxia produced by Immobilon; the posture of lateral recumbency, the decrease in respiratory rate and the laboured character of the respirat...
Datt SC, Usenik EA.Physical signs and blood changes were studied in horses with artificially produced obstructions of the duodenum and the small colon and simulated volvulus of the ileum. Horses with obstruction of the duodenum had the most violent physical signs and the shortest survival time. Blood changes were an initial rise in pH followed by acidosis, hyperkalemia and a decrease in HCO3 minus, Na+ and C1 minus. Obstruction of the small colon resulted in mild physical signs. The blood parameters recorded were normal. Simulated volvulus resulted in continuous colic. Blood changes were acidosis and hyperkalemi...
Boles C.Adequate post-operative management of equine abdominal patients is as necessary to patient survival as the most heroic corrective surgery. Post-operative management must begin during the anaesthesia recovery phase to insure adequate oxygen supply, ventilation, and minimize any abdominal discomfort. The animal's physiological status must be constantly monitored to detect and determine the degree of abnormalities concerning serum electrolytes, fluid balance, and acid-base abnormalities. The most commonly observed serum electrolyte imbalance is hypokalaemia. Replacement potassium is usually suppl...
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...
Tate LP, Corbett WT, Foreman JH, Bishop BJ, Sweeney CL.A device was constructed of easily obtained medical supplies, and hardware and could be used to obtain multiple arterial samples when manually triggered. The right carotid arteries in five normal horses were surgically elevated, thereby permitting percutaneous cannulation. Each horse was galloped on a 1.6-km test track at approximately 500 m/min, and the rider triggered the mechanism at each 0.4-km mark. Each horse underwent 10 test gallops, and a mean and standard error was determined for each sampling mark including preexercise and postexercise samples. The results indicated that horses ridd...
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...
Raisbeck MF, Garner HE, Osweiler GD.Gram negative endotoxins play a contributory role in the syndrome which results from over consumption of carbohydrates by horses and ponies. Since the antibiotic polymyxin B exerts a direct anti-endotoxin effect by chemically modifying the active lipid A moiety of endotoxin, it might be expected to protect horses after carbohydrate overload and provide a new therapeutic and experimental tool for this condition. The present study was undertaken to evaluate the effect of polymyxin B on hemostatic, hemodynamic, acid-base, and clinical aspects of the syndrome resulting from carbohydrate overload. ...
Steffey EP, Dunlop CI, Cullen LK, Hodgson DS, Giri SN, Willits N, Woliner MJ, Jarvis KA, Smith CM, Elliott AR.Cardiovascular and respiratory changes that accompany markedly long periods (12 hours) of halothane anesthesia were characterized. Eight spontaneously breathing horses were studied while they were positioned in left lateral recumbency and anesthetized only with halothane in oxygen maintained at a constant end-tidal concentration of 1.06% (equivalent to 1.2 times the minimal alveolar concentration for horses). Results of circulatory and respiratory measurements during the first 5 hours of constant conditions were similar to those previously reported from this laboratory (ie, a time-related sign...
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...
Manohar M, Goetz TE, Hassan AS.Work is required to establish the role of endogenous nitric oxide (NO) in metabolism of resting and exercising horses. Objective: To examine the effects of NO synthase inhibition on O2 extraction and anaerobic metabolism at rest, and during submaximal and maximal exertion. Methods: Placebo and NO synthase inhibition (with Nomega-nitro-L-arginine methyl ester [L-NAME] administered at 20 mg/kg bwt i.v.) studies were performed in random order, 7 days apart on 7 healthy, exercise-trained Thoroughbred horses at rest and during incremental exercise leading to 120 sec of maximal exertion at 14 m/sec ...
Klein HJ, Schulze E, Deegen E, Giese W.In 5 horses, 13CO2/12CO2 ratios in expired air were determined using isotope mass spectroscopy to investigate metabolism of naturally occurring [13C]glucose. Oral glucose tolerance tests (OGTT) were performed using maize or beet glucose. Maize has a higher 13C concentration than that of most plants. The 13CO2/12CO2 ratios after OGTT was performed using maize glucose were compared with 13CO2/12CO2 ratios in expired air after OGTT was performed using beet glucose. The ratio also was determined during the period horses were not fed. Using OGTT, all horses were glucose tolerant. The OGTT performed...
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...
Spurlock GH, Landry SL, Sams R, McGuirk S, Muir WW.Plasma volume, extracellular fluid volume (ECFV), and total body water (TBW) were measured before and after endotoxin (Escherichia coli) administration in 6 conscious adult horses. Evan's blue dye, sodium thiocyanate, and antipyrine were the test substances used to estimate plasma volume, ECFV, and TBW, respectively. Pharmacokinetic analysis of plasma concentration vs time was used to determine changes in body fluid compartments. The pathophysiologic effects of endotoxin were monitored by clinical evaluation, blood chemical changes, and blood gas determinations. All horses became dyspneic with...
Orr JA, Erichsen DF, Shirer HW, Allen PL, Payne PA.The aim of this study was to determine whether increases in ventilation would occur during intravenous acid infusion even if systemic arterial pH was held constant. In six awake ponies, HCl (500 ml, approximately 0.312 M) was infused into the right atrium at a total dose of 1.0 meq/kg over 18 min while an equivalent dose of NaOH was infused into the left heart to restore systemic arterial pH to normal. Total ventilation increased at the onset of the infusion and remained elevated although systemic arterial pH was normal to slightly alkaline. The increase in ventilation during the initial 2 min...
Maisi P, Paananen M, Koivunen AL.Seventeen trotters, eight healthy and nine with a mild respiratory disease, underwent a submaximal treadmill exercise. Heart rate, breathing frequency, intrapleural pressure difference (IP difference) as well as haematocrit and concentration of lactic acid in blood were monitored before exercise, during exercise and during recovery. The activities of beta-glucuronidase and plasmin, total proteolytic activity and trypsin inhibitory capacity were measured from the tracheal fluid before and after exercise. IP difference significantly increased during exercise and returned to normal values within ...
Gossett KA, McCoy DJ, Jowett PL, Kearney MT.Nitrofurazone solution containing 0.2% nitrofurazone and 99.8% polyethylene glycol was given to 4 healthy horses (2 L in 2 L of lactated Ringer solution, intraperitoneally). Horses developed hypovolemia, hyperosmolality, and mixed respiratory and metabolic acidosis. These changes were largely attributable to polyethylene glycol, but a contribution of nitrofurazone cannot be excluded. Intraperitoneal infusion of nitrofurazone solution in horses is contraindicated.
Manohar M, Goetz TE, Nganwa D.Diaphragmatic O2 and lactate extraction were examined in seven healthy ponies during maximal exercise (ME) carried out without, as well as with, inspiratory resistive breathing. Arterial and diaphragmatic venous blood were sampled simultaneously at rest and at 30-s intervals during the 4 min of ME. Experiments were carried out before and after left laryngeal hemiplegia (LH) was produced. During ME, normal ponies exhibited hypocapnia, hemoconcentration, and a decrease in arterial PO2 (PaO2) with insignificant change in O2 saturation. In LH ponies, PaO2 and O2 saturation decreased well below tha...
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...
Soma LR, Uboh CE, Nann L, Gerber AL.The administration of sodium bicarbonate (NaHCO3) or 'milk shakes' to Standardbred horses before racing is widespread. This study analysed nonrace day (CTL) and prerace venous acid-base values from Standardbred horses racing in Pennsylvania (PA) and New Jersey (NJ). Mean +/- s.d. CTL bicarbonate (HCO3) and base excess (BE) values, for a group of horses stabled during the 1993 racing season at Pocono Downs, Pennsylvania, were 28.6 +/- 1.9 and 2.6 +/- 1.7 mmol/l, respectively. In the same population of horses, mean +/- s.d. values for prerace HCO3- and BE values were 33.1 +/- 2.8 and 7.0 +/- 2.3...
Gasthuys F, Vandamme R, De Moor A, De Meurichy W.A commercial neuroleptanalgesic acepromazine-etorphine combination administered intramuscularly to four horses produced a severe tachycardia and an increase in muscular tone, together with hypoxaemia, hypercapnia, metabolic acidosis associated with an increase in the packed cell volume and hyperglycaemia. No electrolyte changes were found. After reversal of the action of etorphine with diprenorphine, there was a prolonged decrease in the calcium and phosphorus serum concentrations and decreases in the packed cell volume and the total protein serum concentration. In a second experiment on the s...
Wolter R, Durix A, Letourneau JC, Carcelen M, Henry N.One pony has been subjected to the intravenous injections of L-lactic acid. Two other ponies have been trained to intracaecal administration of L-lactic acid or sucrose. The obtained results show that: Intravenous injection of lactic acid increases the concentration of histamin and lactic acid, decreases the level of magnesium and reduces the pressure of carbon dioxide in the blood (the control animals and the treated animals) without the clinical symptoms of lactic acidosis. Intracaecal administration of lactic acid induces a high liberation of histamin in the caecum (the control animals and ...
Meyer C, Gerber R, Guthrie AJ.A 4-year-old Thoroughbred gelding racehorse was referred to the Onderstepoort Veterinary Academic Hospital (OVAH) with a history of post-race distress and collapse. In the absence of any obvious abnormalities in the preceding diagnostic work-up, a standard exercise test was performed to determine an underlying cause for the post-race distress reported. In this particular case oxygen desaturation became evident at speeds as slow as 6 m/s, where PO2 was measured at 82.3 mm Hg. Similarly at a blood pH of 7.28, PCO2 had dropped to 30.0 mm Hg indicating a combined metabolic acidosis and respiratory...
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...
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 ...
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...
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...
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 ...
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...
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...
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...
Hisaeda K, LE NAT, Kadekaru S, Ono T, Hiasa Y, Ohzawa E, Hata A, Kutara K, Sugimoto K, Une Y, Iwata E, Kunieda T, Zhang C, Kitagawa H.We evaluated metabolic abnormalities in six neonatal Noma foals (Nos. 54-57, 62, and 66) that died shortly after birth, using laboratory tests, pathological examinations, serum amino acid (AA) analyses, gas chromatography/mass spectrometry (GC/MS), and genetic analyses. Nonspecific clinical symptoms, such as poor suckling and weakness, were commonly observed at birth. Sepsis caused by various bacterial infections was detected in foal Nos. 54, 62, and 66, while a heart malformation was identified in foal No. 57. Laboratory tests showed high aspartate transaminase, lactate dehydrogenase, and cre...
Crosby CE, O'Connor A, Munsterman AS.Colic is a significant source of morbidity and mortality in horses, and no single biomarker can distinguish surgical from medical colic or predict mortality. Alactic base excess (ABE) has shown an association with mortality and renal insufficiency in humans but has not been evaluated in veterinary species. The purpose of this study was to determine the value of ABE as a diagnostic tool for horses treated for gastrointestinal disease. Unassigned: This retrospective case series evaluated horses admitted for acute gastrointestinal disease over a 5-year period (2019-2024). Signalment, physical exa...
Mazur SE, Toribio RE.Complications in critically ill equine patients are often related to the underlying disease process but can also be a consequence of diagnostic and therapeutic interventions. Complications can be specific to the affected organ or body system; however, in critically ill patients, they frequently affect the vasculature, acid-base, electrolyte, and fluid balance, energy homeostasis, and coagulation, with systemic consequences. Infrequent monitoring, late detection, failure to adapt therapies, hematologic and biochemical abnormalities, coagulopathies, and systemic inflammation can all contribute t...
Skelton G, Wulster-Bills K, Ciamillo S, Anishchenko S, van Eps A.To characterize healthy foot perfusion patterns under static weight-bearing load using 18F-fluorodeoxyglucose (18F-FDG) PET. Unassigned: In 8 healthy adult light-breed horses (from May 2021 through September 2024), 18F-FDG was injected while horses stood continuously weight-bearing (CWB) for a 20-minute scan period. A repeat scan was then performed after 20 minutes of ambulation. On a separate occasion, scans were performed with ambulation allowed between injection and scanning (Amb_Control). 18F-fluorodeoxyglucose uptake was quantified via metabolic volume and standardized uptake values for c...
