bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intra‐ and Inter‐Day Variability in Plasma Bicarbonate Concentration in Sedentary Horses
Authors: Bergstrom B , Foreman J , Foreman C , Barger A 
Published: June 2014

IntroductionAlkalinizing agents have been given to horses before exercise to provide exogenous buffering effects. The objective of this experiment was to determine the intra‐ and inter‐day variability of resting plasma tCO2. The hypothesis was that tCO2 would vary measurably during a multi‐day quarantine.MethodsEight acclimated sedentary horses had jugular venous samples collected into 10‐ml heparinized evacuated glass tubes 3 times daily (7 AM, 11 AM, and 3 PM) for 5 consecutive days. Horses ate 5.3 kg alfalfa hay at both 7 AM and 3 PM after blood sampling. Plasma tCO2 was determined within 1–3 hours of sampling using an automated chemistry analyzer. Mean tCO2 for all 8 horses was calculated for each of the 15 sampling intervals. Results were compared by Repeated Measures ANOVA. When there was no apparent day‐to‐day effect, data for all horses were pooled by time‐of‐day (n = 40 samples for each of 3 times‐of‐day) and compared by the Student's t test to determine time‐of‐day effect. P<0.05 was considered significant.ResultsMean tCO2 over the 15 sampling intervals ranged from 28.9‐to‐31.6 mmol/L and was lower at 11 AM (Day 1) and 3 PM (Days 1, 3, and 4) compared to 7 AM on Day 1 (P<0.05). Individual plasma tCO2 ranged over 4‐to‐7 units (low 26, high 34, widest range 26–32, narrowest 28–31). Mean pooled tCO2 differed by time‐of‐day, with 11 AM (30.1 ± 0.2, P = 0.011) and 3 PM (29.8 ± 0.2, P<0.001) values lower than 7 AM values (31.0 ± 0.2).ConclusionsPlasma tCO2 differed significantly by time‐of‐day with considerable intra‐ and inter‐individual variability.Ethical Animal ResearchThe study was approved by the University of Illinois Institutional Animal Care and Use Committee. Sources of funding: Fédération Equestre Internationale and Maria Caleel Fund for Equine Sports Medicine Research. Support for Dr. Bergstrom was provided by the Merial Veterinary Scholars Program. Competing interests: none.
Lactate Transport in Red Blood Cells by Monocarboxylate Transporter MCT1 and Its Accessory Protein CD147 In Brazilian Sport Horses of Different Performance Levels
Authors: Feringer Junior WH , Carvalho JRG , Almeida MLM , Queiroz‐Neto A , Ferraz GC 
Published: June 2014

IntroductionThe Brazilian sport horse (BH) was specifically developed for jumping competition. Monocarboxylate transporters are key regulators of cell pH and therefore facilitate co‐transport of protons and lactate. Lactate transport in red blood cells (RBCs) is bimodal (high [HT] and low transport [LT]) and is related to CD147 levels. This study aimed to quantify MCT1 and CD147 protein levels in BH after an incremental jumping test (IJT).MethodsSixteen horses were distributed into two groups: low‐level jumpers (LL, n = 8), able to jump up to 1.00 m, and high‐level jumpers (HL, n = 8), able to jump up to 1.20 m. The IJT consisted of three steps, each with forty jumps at increasing heights (0.40, 0.60, and 0.80 m). Blood samples were collected before and after the IJT. The YSI 2300 method was used to determine plasma lactate concentration [Lac]p. RBC membranes were purified, and MCT1 and CD147 levels were measured by Western blotting. A Student's t‐test and Pearson's correlation (P<0.05) were employed.ResultsThe HL group displayed lower [Lac]p, indicating prevalence of the aerobic pathway in this group. The results showed no difference in the expression of the transporters between times or groups and a positive correlation (r = 0.67, P<0.0001) between MCT1 and CD147. In both groups [Lac]p didn't correlate with the amount of MCT1 or CD147. Most of the horses appeared to have high lactate transport activity. The CD147/MCT1 ratios for LL and HL were equal.ConclusionsBH showed no difference in MCT1 and CD147 expression between conditioning levels.Ethical Animal ResearchAll procedures were approved by the institutional animal care and use committee of the university (CEUA, Process: 019281/13). Explicit owner informed consent for participation in this study is not stated. Sources of funding: FAPESP ‐ Fundação de Amparo à Pesquisa do Estado de São Paulo (Process 2011/11080‐0). Competing interests: none.
“Positive” Plasma tCO2 Tests in Racehorses in New York, Maine, and California Result from Day‐to‐Day Instrument Variability
Authors: Foreman J , Foreman C 
Published: June 2014

IntroductionMany jurisdictions measure plasma tCO2 to determine if racehorses may have been administered exogenous alkalinizers illegally (“milkshakes”). Our hypothesis was that plasma tCO2 test results vary within a racing jurisdiction due to inter‐day instrument variability.MethodsIndividual or daily mean plasma tCO2 test results from New York (n = 584) and Maine (n = 443) Standardbreds and California Thoroughbreds (n = 23,686) were obtained through legal discovery in adjudicated cases where trainers were accused of tampering with horses resulting in tCO2 concentrations ≥37.0 mmol/L. Daily results were grouped by days on which no horse tested ≥37.0 mmol/L (LOW) or days on which at least one horse tested ≥37.0 mmol/L (HIGH). HIGH days were further subsampled by eliminating “positive” test results ≥37.0 mmol/L (MODIFIED HIGH). With P<0.05 considered significant, differences between groups were compared by Student's t test for means and Mann‐Whitney Rank Sum Test for medians.ResultsHIGH tCO2 means (32.9 ± 2.6, 35.2 ± 3.4, 32.6 ± 2.7) and medians (32.9, 35.4, 32.6) for all 3 jurisdictions were higher than LOW means (31.7 ± 2.3, 31.9 ± 4.3, 31.5 ± 0.7) and medians (31.8, 32.9, 31.5) (P<0.001). Even when “positive” tests ≥37.0 were eliminated, MODIFIED HIGH means (32.5 ± 2.2, 33.6 ± 2.6, 32.4 ± 2.5) and medians (32.7, 34.2, 32.5) were still higher than LOW (P<0.001).ConclusionsUnless the population tCO2 mean varies significantly daily, it must be concluded that instrument variability resulted in day‐to‐day differences in plasma tCO2 test results. Without appropriate quality control including correction of individual suspect results to a contemporaneous standard curve, horse trainers may be accused unfairly of tampering when day‐to‐day instrument variability contributes to positive plasma tCO2 test results.Ethical Animal ResearchThis was a retrospective study investigating laboratory results obtained through adjudication of legal cases before various racing commissions. Sources of funding: none. Competing interests: none.
Preliminary Results on CD147 Expression in Red Blood Cells of Arabian Horses
Authors: Regatieri IC , Almeida M LM , Teixeira Neto AR , Ferraz GC , Queiroz‐Neto A 
Published: June 2014

IntroductionDuring anaerobic glycolysis for energy production, lactate and H+ ions accumulate in muscle fibers and pass into the bloodstream. Monocarboxylate transporter type 1 and its ancillary protein CD147 transport H+ and lactate ions from the plasma into red blood cells, thereby maintaining acid/base homeostasis and retarding systemic acidosis and fatigue. The aim of this study was to compare the levels of CD147 protein in the red blood cells of Arabian horses with different levels of athletic ability.MethodsBlood samples were taken from 12 Arabian horses before exercise. The horses were divided into two groups: untrained horses (UH, n = 6) and 160‐km endurance horses (FEI, n = 6). The amount of CD147 in the plasma membranes of their red blood cells was determined by Western blotting analysis using a human‐specific anti‐CD147 antibody previously validated for horses. The medians were compared by Mann‐Whitney Rank Sum test at 5%.ResultsCD147 protein with a molecular mass of approximately 45 kDa was found in the red blood cell membranes of the studied horses. The CD147 expression levels of the two groups were not different (P = 0.065). The observed median values (min–max) were 0.50 (0.37–1.26) and 0.27 (0.09–0.69) arbitrary optical density units for the FEI and UH group respectively.ConclusionsStudies must be performed with more horses to determine if a different level of CD147 expression exists in FEI horses related to their intensive training programs or to the genetic traits of each horse.Ethical Animal ResearchAll procedures were approved by the institutional animal care and use committee of the university (CEUA, Process: 019314/13). Explicit owner informed consent for participation in this study is not stated. Sources of funding: FAPESP ‐ Fundação de Amparo à Pesquisa do Estado de São Paulo. Process: 2012/24193‐0. Competing interests: none.
Real‐Time Monitoring of the Core Body Temperature of Endurance Horses During Field Exercise
Authors: Verdegaal E , Jonas S , Caraguel C , Franklin S 
Published: June 2014

IntroductionContinuous monitoring of core body temperature may provide useful information about the thermal response to metabolic heat load and environmental challenges. The aim of this study was to evaluate a telemetric gastrointestinal (GI) pill (Equivital®) measuring gastrointestinal temperature (GT) during endurance exercise. It was hypothesised that a temperature and metabolic heat profile could be established.MethodsTheGIpill was administered to 6 horses by nasogastric tube (n = 3) or modified‐drench gun (n = 3), the day before competition. During competition,GT, skin temperature and heart rate (HR) were recorded (by Equivital® belt). Other data collected included body weight and rectal temperature (RT),GPS/HRmonitor information, and environmental conditions using a data logger. Metabolic heat production was calculated [1] andGTcorrelations were explored using simple correlation estimates (P<0.05).ResultsData were collected from 6 horses during 80 km (n = 4 horses) and 100 km (n = 2) competition days with mean data loss of 7.4% (±2.4%).GTprofiles showed increasing temperature with cumulative metabolic heat production, and time to reach maximumGTwas 2.14–6.29 h (maximumGTrange: 38.4–39.5°C). During exercise (7 h 6 min ± 1 h 3 min duration), mean and maximum speeds ranged from 10.1–14.5 km/h and 23.5–30.8 km/h, respectively. No correlation was found betweenGTandHR, skin, or environment temperature. MaximumGTincreased with bodyweight (r = 0.775, P = 0.08).GTwas systematically higher thanRT(mean difference +0.46°C).ConclusionsGTwas recorded successfully during competition with minimal data loss. TheGIpill has great potential as a method to further investigate thermoregulation in horses under field conditions.Ethical Animal ResearchAll studies were performed under the AdelaideAnimalEthicsCommittee,University of Adelaide.Explicit owner informed consent for participation in this study is not stated.Sources of funding: The equipment for the project was funded by the Faculty of Science ‘Grant for minor equipment’,University of Adelaide,Australia.Competing interests: none.
Pre‐Race Administration of Furosemide Induces a Linear Dose‐Dependent Increase in Plasma Total CO2 Concentration in Thoroughbred Racehorses
Authors: Demaree A , Couetil L , Constable P 
Published: June 2014

IntroductionFurosemide is widely administered in North America for the prophylactic treatment of exercise‐induced pulmonary hemorrhage. Plasma total CO2 concentration (ctCO2) provides a clinically useful screening test for the presence of metabolic acid‐base disturbances, including the pre‐race administration of alkalinizing agents to racehorses. Some racing jurisdictions account for the metabolic alkalosis and increased plasma ctCO2 induced by furosemide administration. The purpose of this study was to determine the relationship between pre‐race furosemide dose and pre‐race plasma ctCO2 in Thoroughbred racehorses.MethodsJugular venous blood was collected anaerobically into 3 mL partially evacuated plastic tubes containing lithium heparin from 226 Thoroughbred horses administered a variable dose of furosemide (150–500 mg IV, n = 217) 3–4 hours previously or not administered furosemide (n = 9).Plasma ctCO2 was calculated from the measured values for pH and pCO2 using a blood gas and pH analyzer [Radiometer ABL 700] and the Henderson‐Hasselbalch equation. Data was analyzed using multivariable linear regression and P<0.05 was significant.Plasma ctCO2 in mmol/L increased linearly (P = 0.0006) with furosemide dose in milligrams adjusted for sex (female, stallion, gelding), such that ctCO2 = 33.38 − 0.71(if female) − 0.63(if stallion) + 0.0040 × (furosemide dose).ConclusionsIntravenous administration of furosemide (150–500 mg) produces a linear dose‐dependent increase in ctCO2 in plasma. High intravenous doses of furosemide (500 mg) have the potential to increase plasma ctCO2 to near the threshold value used to identify the pre‐race administration of alkalinizing agents. This finding supports an allowance of 2.0 mmol/L for furosemide administration used by some racing jurisdictions in North America.Ethical Animal ResearchSamples and data were collected during race day procedures currently in place. Explicit owner informed consent for participation in this study is not stated. Sources of funding: Indiana Horse Racing Commission. Competing interests: none.
Experimental Determination of the Apparent Value for the First Dissociation Constant (pK1′) of the Plasma Carbonic Acid – Bicarbonate Buffer System in 115 Trained Standardbreds
Authors: Constable P , Tinkler S , Demaree A , Couetil L 
Published: June 2014

IntroductionCalculating the total plasma concentration of carbon dioxide (ctCO2) from the results of blood gas and pH analysis assumes that the value for pK1′ is constant and approximates 6.095. The objective of this study was to verify both assumptions in equine plasma.MethodsDuplicate jugular blood samples were collected pre‐race from 115 trained Standardbreds into 3 mL partially evacuated plastic tubes containing lithium heparin. Blood pH (pHb) and partial pressure of CO2 (pCO2) were measured in one tube using a blood gas and pH analyser (Radiometer ABL‐700). The second tube was anaerobically centrifuged and ctCO2 was measured (Beckman EL‐ISE analyser). Plasma pK1′ was calculated for each horse using the Henderson‐Hasselbalch equation, measured values for pHb, pCO2, and plasma ctCO2, and the value for the solubility of CO2 in plasma at 37C (S = 0.0307 {mmol/L}/mmHg) whereby: pK1′ = (pHb + 0.01)–log10({ctCO2‐S × pCO2}/{S × pCO2}), with the term (pHb + 0.01) representing the pH in plasma. The calculated value for pK1′ was standardized to pHb = 7.40 using the Severinghaus equation such that dpK1′/dpH = −0.044. Non‐parametric statistical procedures were used to determine the median value and 95% confidence interval (CI) for pK1′.ResultsThe median value for pK1′ at pHb = 7.40 was 6.097, and the 95% CI for pK1′ was 6.063–6.123.ConclusionsThe 95% CI for pK1′ in equine plasma from trained Standardbreds is narrow and includes the assumed fixed value of 6.095. Our findings support the use of blood gas and pH analysis to calculate plasma ctCO2 in order to detect the pre‐race administration of alkalinizing agents in horses.Ethical Animal ResearchThe study was approved by the Institutional Animal Care and Use Committee at Purdue University. Sources of funding: Supported, in part, by a grant from the Indiana Horse Racing Commission. Competing interests: none.
The Prevalence of Abnormal Breathing Patterns During Exercise and Associations with Dynamic Upper Respiratory Tract Obstructions
Authors: Fitzharris L , Franklin S , Allen K 
Published: June 2014

IntroductionDuring canter and gallop most horses maintain a locomotor‐respiratory coupling (LRC) ratio of one breath every stride. Occasional big respiratory cycles (BRC) are described when a single breath is taken over two strides. This is considered a transient but normal feature of ventilation. However, a change to a more persistent 2:1 LRC ratio is considered to be ‘abnormal’. It has been suggested that upper respiratory tract (URT) disorders could result in a horse adopting an abnormal breathing pattern, although current information is limited.MethodsSimultaneous audio and URT endoscopy recordings from 365 horses referred for treadmill evaluation were analysed. Breathing pattern at canter and gallop was categorised at each one minute speed step:

Normal: 1:1 with <2 BRC

Normal: 1:1 with 2 BRC

Abnormal: breathing pattern disrupted by repetitive and frequent BRC's

Abnormal: alternating between periods of 2:1 and 1:1

Abnormal: 2:1 throughout
Data analysis was performed using PASW 18.0. A chi‐square test was used to identify associations between breathing pattern and presence of URT obstructions.ResultsDuring the entire exercise test 30% of horses had an abnormal breathing pattern at canter or gallop, of which 23% had a 2:1 breathing pattern. The prevalence of abnormal breathing patterns was higher at low canter speeds than during strenuous exercise. There was a significant association between breathing pattern during strenuous exercise and the presence of an URT obstruction (P = 0.008).ConclusionsLoss of a 1:1 LRC ratio during canter and gallop is more common than previously realised and may be associated with dynamic URT obstructions.Ethical Animal ResearchRetrospective analysis of case records. Sources of funding: none declared. Competing interests: none.
Big Respiratory Cycles During Treadmill Exercise
Authors: Green C , Bayly W , Sides R 
Published: June 2014

IntroductionBig respiratory cycles (BRCs) are a sporadic but normal occurrence during galloping exercise. Their relationship to performance capacity as reflected by maximal oxygen consumption (VO2max) is unclear.Methods7 Thoroughbreds completed multiple incremental exercise tests up to 13 m/s on a treadmill to determine their VO2max while wearing a mask that measured inspired and expired volumes (VI, VE) and VO2 on a breath‐by‐breath basis. Frequency and duration of BRCs were related to speed and VO2max using regression analysis. Numbers of BRCs for each test were counted and the duration, VI, VE and VO2 of each BRC determined and compared to the corresponding average values of the 5 breaths following the BRCs, and VO2max for the exercise bout. Significance was set at P<0.05.ResultsThe frequency of BRCs was 64% when all speeds and runs were considered. The number and appearance of BRCs varied considerably between horses. BRC numbers were greatest at 6 and 13 m/s and least at 9 m/s, and significantly related by polynomial regression (r2 = 0.90). BRC duration was not related to breathing frequency when all BRCs were considered due to the existence of two distinct clusters of BRCs. The duration of those lasting <1.25 s was inversely related to speed (r2 = 0.77) as were those >1.25 s in length (r2 = 0.55). BRC VI and VE were greater than normal VI and VE and the difference increased linearly (r2 = 0.89 and 0.87, respectively) as speed increased from 6 m/s (VI: 8.0 ± 0.6%; VE: 8.9 ± 0.7% greater) to 13 m/s (VI: 42 ± 2%; VE: 57 ± 3% greater). Individual VO2max was not related to the number, length or volume of BRCs.ConclusionsThe frequency, duration and size of BRCs do not affect VO2max and vary considerably within a given treadmill test and between horses.Ethical Animal ResearchProcedures were approved by the Institutional Animal Care and Use Committee (protocol #3807). Sources of funding: Funding was provided by the home department. Competing interests: none.
Comparison of Bronchoalveolar Lavage and Tracheal Aspirate Results in 64 Non‐Thoroughbred Horses Presenting with Respiratory Signs or Exercise Intolerance
Authors: Koskinen H , Raekallio M , Rahkonen E , Rajamäki M , Mykkänen A 
Published: June 2014

IntroductionIt has been debated which airway sampling method, bronchoalveolar lavage (BAL) or tracheal aspirate (TA), is superior in evaluating equine respiratory disease. Most studies suggest BAL is the best sampling method due to better correlation with lung histopathology. In this study we compared BAL and TA results of athletic non‐Thoroughbred horses with chronic respiratory signs or exercise intolerance during 2009–2013.Methods64 horses, 2–25 years of age (16 Coldbloods, 30 Warmbloods, 11 Standardbreds, 7 ponies) with recurrent or chronic (duration >1 month) respiratory signs or exercise intolerance that were subject to both BAL and TA sampling at rest were included. Neutrophil counts >5% in BAL and >20% in TA were considered abnormal. Statistical analysis was performed with Spearman's correlation coefficient.ResultsBoth BAL and TA were abnormal in 29 horses and normal in 26 horses. 7 horses had only abnormal TA and 2 horses only abnormal BAL. Correlation was found between the amount of mucus in the trachea and both BAL (P = 0.002) and TA (P<0.001) neutrophil percentage. Neutrophil (P<0.001), eosinophil (P<0.001), lymphocyte (P = 0.008) and macrophage (P = 0.004) percentages correlated between BAL and TA.ConclusionsIn our university hospital population, mucus in the trachea was a good indicator of airway neutrophilia. Unlike previous studies, in only 14% of the horses the interpretation of BAL and TA result was different with TA being slightly more sensitive at detecting neutrophilia. However, a gold standard for detecting inflammation in the equine airways is still lacking and the type and severity of the disease may greatly influence the best choice of sampling method.Ethical Animal ResearchRetrospective analysis of case records. Sources of funding: none. Competing interests: none.
Cardiac Morphology and Heart Murmurs in Elite Eventing and Dressage Horses
Authors: Wijnberg ID , Maarsse J , van Kampen W , Veraa S 
Published: June 2014

IntroductionTraining related cardiac adaptation is documented in Standardbreds and Thoroughbreds, including an increased incidence of AV valve regurgitation. In Warmbloods less is known about training effects on cardiac function or subclinical valve regurgitation.MethodsFifteen adult untrained Warmbloods (aged 3.8 ± 0.7 years) were compared with fifteen adult Warmblood eventers (aged 11.4 ± 0.9 years) competing at CIC2* (group 1, n = 5) and CCI2*, CIC3*, CCI3* and CCI4*levels (group 2, n = 9) and fifteen healthy adult Warmbloods competing at advanced dressage (group 3, n = 5), Prix Saint Georges, Intermediate or Grand Prix (group 4, n = 10) levels (mean age 10.3 ± 0.7 years). The presence of heart murmurs, valve regurgitation and echocardiographic parameters were evaluated, and training intensity was scored. A correlation was found between bodyweight and not height. Differences in cardiac morphology were compared using General Linear Models with post‐hoc Bonferroni correction (SPSS version 20), using group and bodyweight as covariates. Significance was set at P<0.05.Prevalence of audible heart murmurs and valvular regurgitation was higher in eventers (0–20% and 29–79%, respectively and dressage horses (7–40% and 7–60%, respectively) than controls (0–20% and 7–20%, respectively). Interventricular septum in diastole (IVSd, left ventricular mass (LVM) and LV mean wall thickness (LVMWT) were greater in groups 2 and 4 than controls; group 4 also had a greater pulmonary artery diameter (PAD) and LV posterior wall (LVPWd). Group 1 showed a greater LVMWT; group 4 a greater end point septal separation (EPSS). Training intensity influenced in both categories IVSd and MWT; in eventers also the right ventricular diameter in diastole and in dressage horses also LVPWd, LVM, EPSS and PAD.Elite eventers and dressage horses showed an increased prevalence of audible murmurs and valvular regurgitation. Cardiac adaptations resembled those associated with resistance and endurance training. Increased performance level and training intensity accompanied increased cardiac muscle thickness and volume. These effects should be considered during sales and performance evaluations.Ethical Animal ResearchEvaluated by the Animal Ethics Committee of Utrecht University and owner consent was obtained. Sources of funding: Faculty of Veterinary Medicine, Utrecht University. Competing interests: none.