Lactate is a byproduct of anaerobic metabolism, produced when glucose is broken down for energy in the absence of sufficient oxygen. In horses, lactate levels can increase during intense physical exertion, such as racing or other high-performance activities. Elevated lactate concentrations are often associated with muscle fatigue and can provide insights into a horse's exercise physiology and conditioning status. Monitoring lactate levels can aid in assessing the horse's fitness, recovery, and adaptation to training. This page compiles peer-reviewed research studies and scholarly articles that explore the production, regulation, and implications of lactate in equine exercise physiology and performance.
Peloso JG, Cohen ND.To determine the value of serial measurements of peritoneal fluid lactate concentration (PFL) for detecting strangulating intestinal lesions (SLs) in referred horses with signs of colic. Methods: Retrospective cohort study. Methods: 94 horses with signs of colic. Methods: Medical records of horses evaluated between September 2006 and February 2010 because of signs of colic were reviewed. All included horses had ≥ 2 peritoneal fluid samples collected, including one at admission and another within 1 to 6 hours after admission. Of the 94 horses, 26 were assigned to the SL group on the basis of ...
Jansson A, Lindberg JE.Most athletic horses are fed a high-starch diet despite the risk of health problems. Replacing starch concentrate with high-energy forage would alleviate these health problems, but could result in a shift in major substrates for muscle energy supply from glucose to short-chain fatty acids (SCFA) due to more hindgut fermentation of fibre. Dietary fat inclusion has previously been shown to promote aerobic energy supply during exercise, but the contribution of SCFA to exercise metabolism has received little attention. This study compared metabolic response with exercise and lactate threshold (VLa...
Botha M, Botes M, Loos B, Smith C, Dicks LM.Lactobacillus equigenerosi strain Le1, a natural inhabitant of the equine gastrointestinal tract, survived pH 3.0 and incubation in the presence of 1.5% (wt/vol) bile salts for at least 2 h. Strain Le1 showed 8% cell surface hydrophobicity, 60% auto-aggregation, and 47% coaggregation with Clostridium difficile C6. Only 1% of the cells adhered to viable buccal epithelial cells and invaded the cells within 20 min after contact. Preincubation of strain Le1 in a buffer containing pronase prevented adhesion to viable epithelial cells. Preincubation in a pepsin buffer delayed invasion from 20 min to...
Lindner A, Dag Erginsoy S, Kissenbeck S, Mosen H, Hetzel U, Drommer W, Chamizo VE, Rivero JL.The effects of three different blood-guided conditioning programmes on ultrastructural and histochemical features of the gluteus medius muscle of 2-year-old sport horses were examined. Six non-trained Haflinger horses performed three consecutive conditioning programmes of varying lactate-guided intensities [velocities eliciting blood lactate concentrations of 1.5 (v1.5 ), 2.5 (v2.5 ) and 4 (v4 ) mm respectively] and durations (25 and 45 min). Each conditioning programme lasted 6 weeks and was followed by a 5-week resting period. Pre-, post- and deconditioning muscle biopsies were analyse...
Kang OD, Ryu YC, Yun YM, Kang MS.The changes in physiologic parameters by swim exercise duration were examined in five female well-trained Jeju crossbred riding horses that had riding experience of more than three years without swim training experience. The horses were performed with swim exercise for 10 min (60.0 m/min) once a day for 14 days. Physiologic characteristics and haematic parameters were measured before swimming, immediately after swimming, and after a 10 min rest at first day (D0), 7 days (D7), and 14 days (D14) of training. After 14 days of swim training, heart rate (p<0.05), blood glucose (p<0.05), lacta...
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...
Muñoz A, Riber C, Trigo P, Castejón F.In order to assess which laboratorial parameters need specific age- and/or gender-related reference values, hematological and biochemical profiles (including hormones) were performed in 205 Spanish foals of 5 groups: A (1-2 months; 20 fillies, 10 colts), B (2-3 months; 24 fillies, 18 colts), C (3-6 months; 25 fillies, 16 colts), D (6-9 months; 20 fillies, 23 colts) and E (9-12 months; 25 fillies, 15 colts). Additionally, 120 adult horses were sampled in order to establish baseline data for this breed in our laboratory. Group E had lower red blood cell number and mean cell volume than B, C and ...
Tennent-Brown BS.Blood lactate concentration can be easily measured by practitioners using inexpensive point-of-care meters. Anaerobic tissue metabolism resulting from inadequate oxygen delivery (DO2) is the most important cause of an increase in blood lactate concentration in equine patients. However,hyperlactatemia also occurs under conditions of apparently adequate DO2, usually in association with sepsis and an intense inflammatory reaction. Numerous mechanisms have been proposed for aerobic hyperlactatemia, including increased Na+/K+-ATPase activity in response to inflammatory mediators; inhibition of pyru...
Hashimoto-Hill S, Magdesian KG, Kass PH.Serial measurement of lactate concentration is utilized for therapeutic and prognostic purposes in human critical care. The prognostic value of serial lactate measurement in equine acute colitis warrants investigation. Objective: Serial lactate concentrations are predictive of outcome in horses with colitis. Methods: A total of 101 horses with colitis. Methods: Retrospective study. Plasma L-lactate concentrations were measured at admission and at 4-8 and 24 hours after admission. Associations between admission, early (4-8 hours) and late (24 hours) lactate concentrations, and survival status w...
Koho NM, Mykkänen AK, Reeben M, Raekallio MR, Ilves M, Pösö AR.MCT1-CD147 complex is the prime lactate transporter in mammalian plasma membranes. In equine red blood cells (RBCs), activity of the complex and expression of MCT1 and CD147 is bimodal; high in 70% and low in 30%. We studied whether sequence variations contribute to the bimodal expression of MCT1 and CD147. Samples of blood and cremaster muscle were collected in connection of castration from 24 horses. Additional gluteus muscle samples were collected from 15 Standardbreds of which seven were known to express low amounts of CD147 in RBCs. The cDNA of MCT1 and CD147 together with a promoter regi...
Daly K, Proudman CJ, Duncan SH, Flint HJ, Dyer J, Shirazi-Beechey SP.We aimed to determine the effects of variations in dietary composition on equine gut microbiota and their fermentation products, and proposed that dietary modifications profoundly affect microbial ecosystems and their metabolites. Bacterial communities within the large intestine of three groups of horses were compared using oligonucleotide-RNA hybridisation methodology. Each group consisting of six horses was maintained on (1) a grass-only diet, (2) a concentrate diet (i.e. supplemented with hydrolysable carbohydrates) and (3) a concentrate diet but horses were affected by simple colonic obstr...
Yamout SZ, Nieto JE, Beldomenico PM, Dechant JE, leJeune S, Snyder JR.To evaluate the association between peritoneal fluid and plasma d-lactate concentration with variables used in the diagnosis and prognosis of horses with colic. Methods: Clinically healthy horses (n=6) and 90 horses with colic. Methods: Prospective cross-sectional study. Methods: D-lactate concentration was determined in peritoneal fluid and plasma of all horses. Information on other blood and peritoneal fluid variables, signalment, results from the physical examination, outcome, need for surgery, lesion location, and type was retrieved from medical records. Results: Peritoneal D-lactate conce...
Kitaoka Y, Hoshino D, Mukai K, Hiraga A, Takemasa T, Hatta H.To examine the changes in monocarboxylate transporter (MCT) 1 and MCT4 content and in indicators of energy metabolism in the gluteus medius muscle (GMM) of Thoroughbreds during growth. Methods: 6 Thoroughbreds (3 males and 3 females). Methods: Samples of GMM were obtained when horses were 2, 6, 12, and 24 months old. Muscle proteins were separated via SDS-PAGE; amounts of MCT1 and MCT4 and peroxisome proliferator-activated receptor-γ coactivator-1α content were determined by use of western blotting. Muscle activities of phosphofructokinase and citrate synthase were measured biochemically; la...
Dechant JE, Symm WA, Nieto JE.To compare agreement between a portable clinical analyzer and laboratory-based bench-top analyzer for analysis of pH, lactate, and glucose concentrations in synovial fluid. Methods: Prospective experimental study. Methods: Clinically normal horses (n=8); 6 horses euthanatized for reasons unrelated to the study; 11 horses that had synoviocentesis for reasons other than sepsis; 7 horses that had synoviocentesis for evaluation of sepsis; and 2 horses without recorded clinical data. Median age of horses was 8 years (range, 1 day to 24 years). Methods: Supernatant from each synovial fluid sample wa...
Lindner A, Wäschle S, Sasse HH.The blood lactate concentration (LA) and heart rate (HR) of 10 horses exercising in water on a treadmill were examined. With the water at 10 and 50% of the withers height (WH), the blood LA increased up to mean values around 1.9 mm during the standardized exercise test (SET) until after step 3 of 5 (each step lasted 5 min, speed increasing step by step). Thereafter, blood LA of horses remained constant, while with the water at 80% of WH, the blood LA decreased from the mean peak of 2.16 ± 0.62 mm after the 4th step. The HR of the horses increased to 132 ± 14 beats/min until the 3rd step of S...
Wendt-Hornickle EL, Snyder LB, Tang R, Johnson RA.To investigate changes in colloid osmotic pressure (COP), total protein (TP) and osmolality (OSM) during anesthesia in horses given intravenous lactated Ringer's solution (LRS) or LRS and hetastarch (HES). Methods: Prospective, clinical trial. Methods: Fourteen horses presented for surgery. Mean age 8.3 ± 1.9 years; mean weight 452 ± 25 kg. Methods: Horses were premedicated with xylazine intravenously (IV); anesthesia was induced with ketamine and diazepam IV, and maintained with sevoflurane. Butorphanol was administered IV with pre-medications or immediately after induction. Xylazine was ad...
Butudom P, Foreman JH, Kline KH, Whittem EL.Some methods of lactate (LA) measurement have not been validated appropriately for use in horses. Objective: To validate 2 LA analysers (YSI 2300 Stat Plus and TDx Lactic Acid Assay) for use with equine plasma and to compare plasma [LA] determined by the 2 methods. Methods: Both instruments were evaluated for linearity, parallelism, recovery and precision using serial dilutions of standard LA solutions and equine plasma and then comparing results with linear regression or paired t tests. Plasma [LA] results were compared in 275 blood samples collected from horses exercising at various intensit...
Mukai K, Hiraga A, Takahashi T, Ohmura H, Jones JH.Several studies have indicated that even low-intensity warm-up increases O(2) transport kinetics and that high-intensity warm-up may not be needed in horses. However, conventional warm-up exercise for Thoroughbred races is more intense than those utilised in previous studies of equine warm-up responses. Objective: To test the hypothesis that warm-up exercise at different intensities alters the kinetics and total contribution of aerobic power to total metabolic power in subsequent supramaximal (sprint) exercise in Thoroughbred horses. Methods: Nine well-trained Thoroughbreds ran until fatigue a...
Ohmura H, Mukai K, Takahashi T, Matsui A, Hiraga A, Jones JH.Accumulated O(2) deficit (AOD) and plasma lactate accumulation rate (PLAR) are alternative methods for estimating net anaerobic energy utilisation (NAEU) in exercising horses. How they compare or their accuracy is unknown. Objective: We hypothesised net anaerobic energy utilisation calculated by PLAR (NAUE(PLAR)) is equivalent to NAUE estimated by AOD (NAUE(AOD)). Methods: Six Thoroughbred horses ran at identical supramaximal speeds (118% aerobic capacity) until exhaustion for 2 runs while breathing normoxic (NO, 21% O(2)) or hyperoxic (HO, 26% O(2)) gas. Jugular blood was sampled at 15 s inte...
Revold T, Mykkänen AK, Karlström K, Ihler CF, Pösö AR, Essén-Gustavsson B.Muscular changes caused by training are breed-specific and studies on the Norwegian-Swedish Coldblooded Trotter (NSCT) are limited. Knowledge about lactate-transporters in muscle in this light draught breed used for harness racing is lacking. Objective: To identify muscular changes associated with training in young NSCTs and investigate muscular distribution of the monocarboxylate transporter 1 (MCT1) and its ancillary protein CD147, which facilitate lactate transport across membranes. Methods: Nine horses were followed from the start of their training period until the end of their 3-year-old ...
Fonseca RG, Kenny DA, Hill EW, Katz LM.Fitness assessment can be challenging. The use of global positioning systems (GPS) with heart rate (HR) monitors has been promising; however, evaluation of speed parameters during training has not been reported. Objective: To evaluate speed indices during training in Thoroughbreds using a GPS-HR monitor. Methods: Thoroughbreds (n = 102) were assessed during training with data collected each work day (WD; sprinting). Speed indices evaluated included maximal velocity (V(max)), duration at V(max) (V(maxt)), acceleration rate (m/s(2)) from 800 m to V(max) (Acc800-V(max)), the distance (m) 6 (V(max...
Borgia LA, Valberg SJ, Essen-Gustavsson B.Flexor tendon injury may be due to flexor muscle fatigue, contributing to fetlock joint hyperextension and tendon damage. A water treadmill provides resistance training on flexor tendon muscles, which might reduce the risk of tendon injury. Objective: To determine the effect of water treadmill training on the properties of the gluteal and superficial digital flexor (SDF) muscles and on cardiocirculatory response to a standardised exercise test. Methods: Five healthy unfit horses were trained on a water treadmill for 5 days/week for 4 weeks, starting with 5 min/day increasing to 20 min/day. Bef...
Kallings P, Persson SG, Essén-Gustavsson B.Since nonsteroidal anti-inflammatory drugs, such as flunixin, on account of their anti-inflammatory and analgesic properties, are used in both racing and equestrian sport horses, the question has been raised as to whether these drugs affect the physiological responses to exercise and thus performance potential. Objective: The aims of this investigation were to study the effects of flunixin on cardiorespiratory, metabolic and locomotor parameters in horses during intense treadmill exercise. Methods: Six Standardbred trotters underwent an incremental treadmill exercise test to fatigue, without d...
Courouce-Malblanc A, Deniau V, Rossignol F, Corde R, Leleu C, Maillard K, Pitel PH, Pronost S, Fortier G.Dorsal displacement of the soft palate (DDSP) is one of the most common obstructive conditions of the upper respiratory tract in the racehorse. This condition has a complex aetiology which may be caused or exacerbated by pharyngeal inflammation. Additionally, lower respiratory airway diseases may be associated with DDSP thereby contributing to exercise intolerance in these horses. Objective: The aim of this study was to measure physiological variables during a standardised exercise test and to assess the prevalence and consequences of lower respiratory airway disease in horses with DDSP. Metho...
Ferraz GC, Soares OA, Foz NS, Pereira MC, Queiroz-Neto A.This study was designed to consider the complexity of the physical effort inherent to horses in polo competitions and the absence of reports in the literature on the effort, intensity and electrolyte changes resulting from a collective team training session aimed at preparing for a polo championship. Objective: To determine the effort and ion changes caused by an outdoor polo training match for a 25 goal handicap (elite) based on physiological variables including acid-base status (venous pH, PCO(2) and HCO(3)(-)), packed cell volume (PCV), haemoglobin (Hb), lactate, glucose, sodium, chloride a...
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...
Mykkänen AK, Pösö AR, McGowan CM, McKane SA.In exercising horses, up to 50% of blood lactate is taken up into red blood cells (RBCs). Lactate transporter proteins MCT1, MCT2 and CD147 (an ancillary protein for MCT1) are expressed in the equine RBC membrane. In Standardbreds (SB), lactate transport activity is bimodally distributed and correlates with the amount of MCT1 and CD147. About 75% of SB studied have high lactate transport activity in RBCs. In other breeds, the distribution of lactate transport activity is unknown. Objective: To study whether similar bimodal distribution of MCT1 and CD147 is present also in the racing Finnhorse ...
McCoy AM, Hackett ES, Wagner AE, Mama KR, Hendrickson DA.To characterize pulmonary gas exchange and arterial lactate in horses with gastrointestinal disease undergoing anesthesia, compared with elective surgical horses, and to correlate these variables with postoperative complications and mortality. Methods: Prospective clinical study. Methods: Horses undergoing emergency laparotomy for acute intestinal disease (n = 50) and healthy horses undergoing elective surgery in dorsal recumbency (n = 20). Methods: Arterial blood gas analysis was performed at predetermined intervals on horses undergoing a standardized anesthetic protocol. Alveolar-arterial ox...
Rudi K.Mainly due to the lack of time-series data, we know very little about the underlying interactions leading to adverse states in the gut. I therefore investigate the host-bacteria dynamic interactions in a recently published acidotic state induction time-series experiment. Too high levels of fermentation in the hindgut may lead to elevated serum lactate levels, which is a characteristic of the acidotic state. The acidotic state was induced through injection of oligofructose directly into the caecum of five horses, with subsequent temporal measurements of host serum lactate, and a range of caecum...
Cravana C, Medica P, Ragonese G, Fazio E.To investigate the effects of training sessions on circulating β-endorphin changes in sport horses before and after competition and to ascertain whether competition would affect this response. Methods: A total of 24 trained jumping horses were randomly assigned to one of two training groups: Group A (competing) and Group B (not competing). To determined plasma β-endorphin concentrations, two pre- and post-competition training weeks at aerobic workout and two competitive show jumping event days at anaerobic workout were measured before, 5 and 30 min after exercise. Exercise intensity is descr...
Brunner J, Wichert B, Burger D, von Peinen K, Liesegang A.This study aims at the comparison of the actual feeding of horses with the recommendations from the literature, and it studies the effects of feeding and exercise on several blood metabolic parameters before and after exercise. Blood samples were collected from 25 horses during one-star eventing competitions and evaluated for blood glucose, insulin, lactate, free fatty acids and triglyceride levels. Questionnaires on the feeding practices of the horses were evaluated. The questionnaires revealed that during training, and on tournament days, horses received on average 4.3 kg of concentrate per ...
Revold T, Mykkänen AK, Karlström K, Ihler CF, Pösö AR, Essén-Gustavsson B.Muscular changes caused by training are breed-specific and studies on the Norwegian-Swedish Coldblooded Trotter (NSCT) are limited. Knowledge about lactate-transporters in muscle in this light draught breed used for harness racing is lacking. Objective: To identify muscular changes associated with training in young NSCTs and investigate muscular distribution of the monocarboxylate transporter 1 (MCT1) and its ancillary protein CD147, which facilitate lactate transport across membranes. Methods: Nine horses were followed from the start of their training period until the end of their 3-year-old ...
Harris P, Snow DH.To study the effect of short term high intensity exercise on plasma lactate, potassium, sodium and chloride concentrations, five Thoroughbred horses were galloped on a treadmill at a 5 degree incline. Following a standardised warm-up period, they were galloped at 8, 10, or 12 metres/sec for 2 mins. One horse also galloped at 14 metres/sec for 1.5 mins. Sequential arterial and/or venous blood samples were collected during exercise and recovery. At 12 metres/sec, the effect of different recovery modes, ie, standing, walking or trotting, on the electrolytes was also examined. There was a progress...
The Journal of physiologyOctober 6, 2000
Volume 528 Pt 1, Issue Pt 1 209-219 doi: 10.1111/j.1469-7793.2000.00209.x
Fowden AL, Taylor PM, White KL, Forhead AJ.1. Using the Fick principle and tracer methodology, the metabolic rates of chronically catheterized fetal foals (n = 24) were measured at different gestational ages during the second half of gestation and in response to maternal fasting for 36 h in late gestation (n = 4, term approximately 335 days). 2. Absolute rates of umbilical blood flow, fetal glucose utilization and umbilical uptake of oxygen (O2) and glucose increased from mid-gestation to 300 days and then plateauxed until term. The absolute rate of umbilical lactate uptake was significant after, but not before, 280 days of gestation. ...
Witkowska-Piłaszewicz O, Cywińska A, Michlik-Połczyńska K, Czopowicz M, Strzelec K, Biazik A, Parzeniecka-Jaworska M, Crisman M, Witkowski L.Breed specific reference ranges for selected blood parameters are recommended for proper interpretation of blood tests, but there are only few reports dealing with ponies. The purpose of this study was to investigate if blood parameters differ among ponies' classes and to check if general normal values for equine species are applicable to ponies. Results: All, except total protein concentration, biochemical parameter significantly (p < 0.05) differed among ponies' classes. The most pronounced difference was noted in blood lactate concentrations, higher (p < 0.001) in the sma...
Saulez MN, Gummow B, Slovis NM, Byars TD, Frazer M, MacGillivray K, Bain FT.Veterinary internists need to prognosticate patients quickly and accurately in a neonatal intensive care unit (NICU). This may depend on laboratory data collected on admission, the cost of hospitalisation, length of stay (LOS) and mortality rate experienced in the NICU. Therefore, we conducted a retrospective study of 62 equine neonates admitted to a NICU of a private equine referral hospital to determine the prognostic value of venous clinicopathological data collected on admission before therapy, the cost of hospitalisation, LOS and mortality rate. The WBC count, total CO2 (TCO2) and alkalin...
Koho NM, Hyyppä S, Pösö AR.Monocarboxylate transporters (MCT) facilitate the transport of lactate across membranes. In red blood cells (RBC) the transport activity varies interindividually due to differences in the amount of an ancillary protein CD147. Similar variations in muscles could have a great influence on lactate accumulation during exercise. Objective: To study the expression of MCT isoforms and CD147 in the middle gluteal muscle. Methods: Venous blood and muscle biopsy samples were taken from 14 Standardbred horses. Lactate transport activity in RBC and the amounts of MCT1, 2, 4 and CD147 were measured. Result...
Anderson MG, Aitken MM.Adrenaline was given intramuscularly to resting horses. It increased heart rate, sweating, blood levels of lactic dehydrogenase, aldolase, creatine kinase, glucose, lactate, free fatty acids and glycerol. Responses to isoprenaline, to noradenaline and to adrenaline after pretreatment with propranolol indicated that beta receptors were involved in stimulation of tachycardia, sweating, lipolysis and muscle glycogenolysis, and alpha receptors in stimulation of liver glycogenolysis and leakage of intracellular enzymes. The time course and relative magnitude of the effects on different enzymes was ...
Castejón F, Rubio D, Tovar P, Vinuesa M, Riber C.Aerobic capacity and fitness was studied in three different horse breeds (Andalusian, Arabian and Anglo-Arabian) using a four-level exercise test of gradually increasing intensity (15, 20, 25 and 30 km/h). The lactate concentration at the first three exercise levels was significantly lower for Arabian and Anglo-Arabian horses relative to Andalusian horses, but similar for the three breeds at the last level. Arabian and Anglo-Arabian horses reached a higher rate than Andalusian horses at plasma lactate concentration of 2 mmol/l (VLA2) and 4 mmol/l (VLA4). Andalusian horses exhibited a significa...
Sewell DA, Harris RC.Adenine nucleotide (AN) degradation has been shown to occur during intense exercise in the horse and in man, at or close to the point of fatigue. The aim of the study was to compare the concentrations of muscle inosine 5'-monophosphate (IMP) and plasma ammonia (NH3) during intense exercise with the concentrations of muscle and blood lactate. Seven trained thoroughbred horses were used in the study. Each exercised on a treadmill for periods of between 30 s and 150 s, at 11 and/or 12 m.s-1. Blood and muscle samples were taken and analysed for lactate and NH3 and adenosine 5'-triphosphate (ATP), ...
Rose RJ, Hodgson DR, Kelso TB, McCutcheon LJ, Bayly WM, Gollnick PD.Changes in blood gases, ions, lactate, pH, hemoglobin, blood temperature, total body metabolism, and muscle metabolites were measured before and during exercise (except muscle), at fatigue, and during recovery in normal and acetazolamide-treated horses to test the hypothesis that an acetazolamide-induced acidosis would compromise the metabolism of the horse exercising at maximal O2 uptake. Acetazolamide-treated horses had a 13-mmol/l base deficit at rest, higher arterial Po2 at rest and during exercise, higher arterial and mixed venous Pco2 during exercise, and a 48-s reduction in run time. Ar...
Yancik SA, McIlwraith CW, Wagner AE, Trotter GW.Creatine kinase (CK) and lactate dehydrogenase (LD) enzyme activities and isoenzymes were determined for synovial fluid, synovial membrane, and articular cartilage from 24 clinically normal equine tarsocrural (tibiotarsal) and femoropatellar joints. All 3 tissues contained LD isoenzymes LD1 to LD5, and CK isoenzymes BB and MM. The CK isoenzyme MB was not found. The similarities in isoenzyme composition of these 3 tissues made differentiation of the source of LD and CK impossible by isoenzyme pattern alone. Reference values for the total enzyme activities of specific joint tissues also had wide...
Evans DL, Priddle TL, Davie AJ.Relationships between racing performance and plasma lactate and uric acid concentrations after racing were investigated in pacing Standardbred racehorses. The study was undertaken in order to better understand factors that limit racing performance. Twenty horses were tested after races of 1760 m and 28 horses after races over 2160 m. Blood samples were taken 30-60 min before and 8 and 30 min after a race. There were no significant differences between the race distances for prerace and 8 min postrace plasma lactates. Significant low correlations were obtained for plasma lactate concentration 8 ...
Anderson MG.The effects of exercise of different intensities on blood concentrations of glucose, lactate, pyruvate, free fatty acids and glycerol were studied in a group of clinically normal horses. Blood lactate, pyruvate and lactate/pyruvate ratio increased during exercise, particularly during galloping. These changes occurred within the first 12-15 seconds of exercise indicating that anaerobic metabolic pathways are brought into use very quickly in the strenuously exercising horse. Since blood glycerol levels were significantly increased during exercise body lipids were also mobilised. At the same time...
Kollias-Baker C, Cox K, Jones J.Omeprazole is a proton-pump inhibitor recently approved in the United States for the treatment of gastric ulcer disease in horses. A study was designed to determine the effects of omeprazole treatment on the physiological indices of performance of horses during incremental treadmill exercise. In a crossover-design study carried out over 2 weeks, five horses completed standardized incremental exercise tests on a high-speed treadmill either with no treatment or treatment with omeprazole. No statistically significant effects of omeprazole were found on the mean maximum responses for specific oxyg...
Stefánsdóttir GJ, Ragnarsson S, Gunnarsson V, Roepstorff L, Jansson A.This study compared the effect of ridden tölt and trot at 3 speeds on physiological responses in trained adult (15.3 ± 1.6 yr) Icelandic horses. The experiment had a crossover design with 8 horses, 2 treatments (incremental exercise test in tölt and trot), and 2 riders. Each horse performed 2 tests per day (1 gait with 2 riders, minimum 4.5 h between) on 2 separate days, with 1 d of rest in between. The exercise test consisted of three 642-m phases at 3.0 m/s (Speed), 4.0 m/s (Speed), and 5.0 m/s (Speed) and was performed outdoors on a 300-m oval gravel riding track in northern Iceland in M...
Kȩdzierski W, Pluta M.Every year a new group of young Polish Konik colts are separated from the forest herds to be trained in the stable breeding system. The aim of this study was to evaluate how the young Polish Konik horses who had been born in a forest reserve adapt to and tolerate draft work. Two groups of 6 horses each were studied: (a) 3- to 4-year-old colts and (b) 7- to 13-year-old stallions. An effort response was estimated by heart rate (HR) registration and biochemical analysis of hematocrit; blood lactic acid (LA) level; and plasma concentration of glucose, triacylglycerols, uric acid, total protein, an...
Magdesian KG, Fielding CL, Rhodes DM, Ruby RE.To evaluate selected hemodynamic, blood gas, and biochemical responses to mild to moderate acute blood loss in standing, awake horses. Methods: Prospective study. Methods: 7 healthy mares. Methods: Each horse was restrained in standing stocks, and its head was maintained in a neutral position; sedatives and tranquilizers were not administered. During a 1-hour period, blood was collected into collection bags by use of a suction pump. The rate of blood collection was approximately 16 mL/kg/h (7.3 mL/lb/h). Thirty minutes after blood collection, the blood was readministered at the same rate. Cent...
Niimura Del Barrio MC, Bennett RC, Hughes JML.Influence of detomidine or romifidine constant rate infusion (CRI) on plasma lactate concentration and isoflurane requirements in horses undergoing elective surgery. Methods: Prospective, randomised, blinded, clinical trial. Methods: A total of 24 adult healthy horses. Methods: All horses were administered intramuscular acepromazine (0.02 mg kg) and either intravenous detomidine (0.02 mg kg) (group D), romifidine (0.08 mg kg) (group R) or xylazine (1.0 mg kg) (group C) prior to anaesthesia. Group D was administered detomidine CRI (10 μg kg hour) in lactated Ringer's solution (LRS), group...
Fortier J, Deley G, Goachet AG, Julliand V.An appropriate energy feeding management that ensures the optimal dietary energy supply according to the energy expenditure (EE) is a crucial component for the horse's performance. The main purpose of this study was to determine the EE during four specific exercises used in the training of Standardbred trotters (promenade, jogging, parcours and interval work-outs). A total of six Standardbred geldings performed four different testing situations on a track. The intensity (expressed in percentage of the maximal velocity over 500 m, i.e. v500) and volume (distance and duration) of the testing sit...
Siegers E, van Wijk E, van den Broek J, Sloet van Oldruitenborgh-Oosterbaan M, Munsters C.Friesian stallions have to complete a 10-week studbook approval test (70-day test) consisting of dressage and driving training for acceptance as a breeding stallion. Training response of the horses to this approval program was evaluated. External workload (EW) of 16 stallions (3.2 ± 0.4 years old) was registered during the 9 weeks preceding the 70-day test (preparation period) and during 70-day test. Ridden indoor standardized exercise tests (SET), measuring heart rate (HR) and plasma lactate concentration (LA) at walk, trot and canter, were performed in week 1 (SET-I), 6 (SET-II) and 10 (SET...
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...
Janiak M, Suska M, Dudzińska W, Skotnicka E.The aim of this study was to evaluate response of blood glutathione status and activity of glutathione-metabolizing antioxidant enzymes in erythrocytes of young trotters in basic training. Nine untrained trotters (aged 16-20 months) were exposed to a 4-month training program based on exercises at low-to-moderate intensity. The conditioning consisted of breaking the horses and running them on distances varying from 4 to 40 km a week. The workloads were increased on a 3-week basis. Exercise intensity was monitored by measuring heart rate and blood lactate. Blood samples were collected at rest, b...
Dembek KA, Hurcombe SD, Stewart AJ, Barr BS, MacGillivray KC, Kinee M, Elam J, Toribio RE.Critically ill foals often present to veterinary hospitals with impaired organ perfusion which can be demonstrated by increased blood L-lactate concentrations. As a compensatory mechanism to low blood pressure and electrolyte abnormalities, aldosterone and arginine vasopressin (AVP) are released to restore organ perfusion and function. Several studies have investigated the ability of blood L-lactate concentrations to predict severity of disease and outcome in critically ill human patients, adult horses and foals. However, information on the aldosterone and AVP response to hypoperfusion and its...
Van Dijk P, Lankveld D, Rijkenhuizen A, Jonker FH.To assess the hormonal, metabolic and physiological effects of laparascopic surgery performed under a sedative analgesic combination of detomidine and buprenorphine in standing horses. Methods: Prospective study. Methods: Eight healthy adult Dutch Warmblood horses and five healthy adult ponies undergoing laparoscopy were studied. Five healthy adult horses not undergoing laparoscopy were used as a control group. Methods: The sedative effect of an initial detomidine and buprenorphine injection was maintained using a continuous infusion of detomidine alone. The heart and respiratory rate, arteria...
Parry BW.Clinical pathology is a valuable adjunct to physical examination of cases of colic. The present review considers evaluation of cases of colic for three main purposes: (1) making a prognosis, (2) deciding whether to operate, and (3) making a diagnosis. Blood tests noted to be useful for prognostication were hematocrit, lactate and urea nitrogen concentrations, pH, anion gap, fibrin/fibrinogen degradation products, antithrombin III activity, prothrombin time, and thrombin time. Horses with a poor prognosis often have relative polycythemia, marked lactic acidosis, high anion gap, azotemia, and co...
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...
Mudge MC, Macdonald MH, Owens SD, Tablin F.To compare viability of equine whole blood stored by 4 different methods, and to establish optimal storage protocols for an equine autologous blood donation program. Methods: In vitro study of stored equine whole blood. Animals- Six healthy adult horses. Methods: Blood from each horse was collected into 4 different containers: glass bottles containing acid-citrate-dextrose solution (ACD), plastic bags containing ACD, citrate-phosphate-dextrose (CPD), and CPD with supplemental adenine (CPDA-1). Blood was stored for 5 weeks and sampled at 2-day intervals. Standard hematologic and biochemical var...
Ronéus N, Essén-Gustavsson B, Lindholm A, Persson S.Blood samples from the jugular vein and muscle biopsies (gluteus medius) in 25 Standardbred trotters were obtained 5-10 min after racing. The biopsies were analysed for fibre type composition and enzymatic profile and blood samples for plasma lactate and ammonia concentrations. Muscle characteristics, plasma lactate and ammonia concentrations after racing were compared with each horse's individual performance index (IPI). The IPI is calculated annually from the individual horse's racing performance (% placing 1, 2 or 3, total annual earnings, average earning per start, and best racing record),...
