Elevated Serum Cardiac Troponin I in Cattle with Theileriosis

Background

Theileria annulata is a blood parasite affecting ruminants. Hemolytic anemia, secondary hypoxia, and vasculitis are the most important features of tropical theileriosis.

Objectives

Evaluation of electrocardiographic findings and changes in cardiovascular biochemical markers including cTnI concentrations in cattle naturally infected with theileriosis in the absence of acute cardiac failure.

Animals

Ninety adult Holstein cattle (>1 year) with clinical and laboratory evidence of theileriosis and 30 healthy cattle served as controls.

Methods

Case‐control study in which blood samples were collected and randomized after clinical, hematologic, parasitologic examination and laboratory confirmation and electrocardiographic recording on all animals, serum cardiac troponin I (cTnI), aspartate aminotransferase (AST), and creatine kinase‐MB (CK‐MB) were evaluated.

Results

Serum concentration of cTnI was significantly higher in cattle with theileriosis (mean: 0.028 ng/mL; range: 0.005–0.21 ng/mL; control mean: 0.011; range: <0.005–0.09 ng/mL; P = .003). There was significant correlation between serum level of cTnI and PCV (r = ?0.257; P < .001) and also between cTnI and parasitemia (r = 0.515; P < .001). Mean serum activities of AST and CK‐MB were 107 ± 46 and 301 ± 103 U/L in sick animals, which were significantly higher than healthy cattle (P = .002 and P = .041, respectively). There were no pathologic arrhythmias detected in sick animals.

Conclusions and Clinical Importance

Theileriosis is a risk factor for elevation of cardiac biomarkers in naturally infected Holstein cattle. Severity of anemia and parasitemia might contribute to the pathophysiology of myocardial damage. The prognostic significance of increased serum cardiac troponin I concentrations in cattle with hemolytic anemia merits further investigation.

     

Resting concentrations of cardiac troponin I in fit horses and effect of racing

ObjectivesTo determine normal resting values for cardiac troponin I (cTnI) in healthy Standardbred, Thoroughbred and Warmblood horses and investigate if racing has an influence on cTnI concentrations.BackgroundMeasuring cTnI concentrations in plasma is the gold standard for detecting myocardial injury in humans. Cardiac troponin I is highly conserved between species and has gained interest as a marker for cardiac injury in horses. Increased levels of cTnI have been reported in association with endurance and short-term strenuous exercise on a treadmill in horses. However, the effect of true racing conditions has not yet been reported.Animals, materials and methodsBlood samples for analysis of cTnI concentrations in plasma were collected from 67 Standardbred racehorses, 34 Thoroughbred racehorses and 35 Warmblood dressage horses at rest. Blood samples were also collected prior to and after racing in 22 Standardbred racehorses and 6 Thoroughbred racehorses.ResultsAll horses except one had resting plasma cTnI concentrations <0.022 μg/L. Mild increases in cTnI concentrations were seen in some horses 1–2 h after the race (1/17 Standardbreds and 2/6 Thoroughbreds) as well as 10–14 h after the race (4/21 Standardbreds and 1/6 Thoroughbreds).ConclusionsResting cTnI concentrations in horses are low but mildly elevated cTnI concentrations may be detected in some horses 1–14 h after racing. These findings could be of importance when evaluating horses with suspected cardiac disease that recently have performed hard exercise.     

The Effect of Different Physical Exercise on Plasma Leptin,Cortisol, and Some Energetic Parameters Concentrations in Purebred Arabian Horses

Leptin is a hormone that coordinates food intake, energy expenditure, and metabolic rate; it is, however, unknown how exercise influences plasma leptin concentration in horses. The aim of the study was to evaluate the exercise-induced changes in plasma leptin concentration in purebred Arabian horses competing in races and endurance rides. A total number of 26 horses (12 purebred Arabian racehorses aged 3–5 years and 14 endurance horses aged 7–14 years) were studied during performing routine physical exercise. From each horse, blood samples were collected at rest and immediately after the exercise session. Concentrations of plasma leptin, cortisol, lactic acid, uric acid, triacylglycerols, glycerol and free fatty acids were determined. Exercise-induced increase in cortisol and free fatty acid values were higher in endurance horses than in racehorses. Neither endurance nor race exercises influenced the plasma leptin concentration. Further research is needed to elucidate the effects of different types of exercise on leptin synthesis and secretion in horses.     

Usefulness of a Point-of-Care Analyzer to Measure Cardiac Troponin I and D-Dimer Concentrations in Critically Ill Horses With Gastrointestinal Diseases

Point-of-care (POC) systems for the joint measurement of Troponin and D-dimers have not been studied in horses. The aim of this study was to perform the validation of a POC system (AQT90 FLEX) for the measurement of cardiac troponin I (cTnI) and D-dimers in the serum of horses with gastrointestinal diseases. The main objective was to evaluate whether or not this system can distinguish healthy animals from diseased animals. A sample of 33 horses was included in the study: control group (n = 10) and horses with gastrointestinal disorders (n = 21), which were classified according to their outcome in survivors (subgroup A = 9) and nonsurvivors (subgroup B = 12). Considering the diagnosis of the process, ill horses were classified into three groups: inflammatory (I = 7), obstructive (O = 9), and strangulating diseases (S = 5). The clinical usefulness of AQT90 FLEX was validated by the study of linearity, coefficient of variation, and detection limits. Later, concentrations of D-dimers and cTnI were measured. A significant increase in both parameters was detected in ill animals (cTnI: control: 0.014 ± 0.01 μg/mL, survivors: 0.27 ± 0.37 μg/mL, nonsurvivors: 0.60 ± 1.21 μg/mL; D-dimers: control: 104.90 ± 30.82 ng/mL, survivors: 1,217.22 ± 1,213.28 ng/mL, nonsurvivors: 1,613.67 ± 1,426.75 ng/mL), although there were no statistically significant differences in concentrations according to diagnosis and outcome. In conclusion, AQT90 FLEX POC analyzer can be used in horses with gastrointestinal diseases to measure cTnI and D-dimer concentrations. It is a quick, practical, and minimally invasive tool that helps in determining the severity of illness.     

Cardiac Troponin I as Compared to Troponin T for the Detection of Myocardial Damage in Horses

Background

Different cardiac troponin I (cTnI) assays give different results. Only 1 manufacturer has marketed troponin T (cTnT) assays. Therefore, cTnT often is preferred for detection of myocardial infarction in human patients. Studies of cTnT in horses are limited.

Objectives

To compare a cTnI and a high‐sensitive cTnT assay (hs‐cTnT) in horses.

Animals

Cardiac troponin I and cTnT were determined in 35 healthy horses (group 1), 23 horses suspected to have primary myocardial damage (group 2a), and 41 horses with secondary myocardial damage caused by structural heart disease (group 2b).

Methods

All cTnI samples were analyzed at laboratory A (limit of detection [LOD]: 0.03 ng/mL), whereas cTnT samples were analyzed at 2 laboratories with the same hs‐cTnT assay (laboratory B, LOD: 10.0 pg/mL; laboratory C, LOD: 4.0 pg/mL).

Results

The median cTnI concentration in group 2a (0.90 ng/mL; range, 0.03–58.27 ng/mL) was significantly higher (P < .001) than in group 1 (0.03 ng/mL; range, 0.03–0.09 ng/mL) or group 2b (0.05 ng/mL; range, 0.03–30.92 ng/mL), and the optimal cut‐off for detection of primary myocardial damage was 0.095 ng/mL (sensitivity: 90.5%, specificity: 100%). Using an LOD of 10.0 pg/mL for all cTnT samples, a cut‐off value of 10.5 pg/mL was found, but sensitivity was low (42.9%). When only samples analyzed at laboratory C (n = 58) were included, a cut‐off of 6.6 pg/mL was found (sensitivity: 81%, specificity: 100%).

Conclusions and Clinical Importance

Despite large quantitative differences, cTnI and cTnT are both useful for detection of myocardial damage in horses.     

Effect of Transvenous Electrical Cardioversion on Plasma Cardiac Troponin I Concentrations in Horses with Atrial Fibrillation

Background: Whether electrical cardioversion of cardiac arrhythmias results in cardiomyocyte damage is unknown.
Objective: To describe effect of transvenous electrical cardioversion (TVEC) on plasma cardiac troponin I (cTnI) concentration in horses.
Animals: All horses presented to the Cornell University Hospital for Animals for cardioversion of atrial fibrillation between May 2006 and October 2008 were eligible for inclusion in the study. Owners of 14 horses elected for TVEC and each horse was then enrolled (16 procedures).
Methods: Prospective observational study measuring concentrations of plasma cTnI before and after TVEC.
Results: Median cTnI concentration increased from 0.045 ng/mL at baseline (range 0.0–0.20 ng/mL) to 0.11 ng/mL after TVEC (range 0.0–3.73 ng/mL) ( P = .036). This increase was not associated with the number of shocks delivered, maximal energy delivered, cumulative energy delivered, chronicity of atrial fibrillation before cardioversion, or positioning of the pulmonary artery catheter.
Conclusions: The increase in cTnI is unlikely to be clinically important. The increase might be correlated with persistent atrial dysfunction after TVEC, suggesting that a longer convalescent period after the procedure could be warranted.     

冷热刺激对犬血清皮质醇、促肾上腺皮质激素及血液生理指标的影响

对体重为4 5±0 5kg的雄性京巴、沙皮和杂种宠物犬,随机分成2组,每组9只,由桡静脉采取自身对照血液后,冷应激组置于0℃的冰水混合物中30min,分别于刺激结束后0h、1h、2h采血;热应激组置于41～42℃的环境中1h,分别于刺激30min和60min时,刺激结束后1h和2h采血。测定血样中的红细胞数、白细胞数、血红蛋白含量、红细胞比容、血沉、红细胞脆性等血液指标,并用放射免疫法测定血清中的皮质醇、促肾上腺皮质激素(ACTH)的浓度。结果表明:在热刺激条件下,各试验期皮质醇和ACTH的浓度均高于各自对照期,但热刺激30min和60min时,与各自对照期相比,皮质醇浓度和ACTH浓度差异均极显著(P<0 01);刺激结束后1h,皮质醇浓度与对照期相比差异仍极显著(P<0 01),ACTH浓度差异显著(P<0 05);刺激结束后2h二者虽都高于对照期,但差异不显著(P>0 05)。冷刺激条件下,各试验期皮质醇和ACTH的浓度均高于各自对照期,其中冷刺激结束时均差异极显著(P<0 01),结束后1h差异显著(P<0 05),结束后2h差异不显著(P>0 05)。冷热刺激对各项血液生理指标也都有或多或少的影响。以上结果显示:上述神经内分泌和血液生理指标的改变与急性冷热应激反应有关,提高了机体对环境变化的适应能力,从而保证生命活动的正常进行。     

The Potential Role of Training Sessions on the Temporal and Spatial Physiological Patterns in Young Friesian Horses

This study compares the circulating adrenocorticotrophin hormone (ACTH), cortisol, lactate, glucose, heart rate, respiratory rate, rectal temperature, and blood count values in initially 2-year-old horses subjected to dressage training schedule during three consecutive days per 2 weeks. Sixteen healthy Friesian horses were used and were considered dressage group. Six healthy young horses not involved in training programs were used as control group. Blood sampling were collected from the jugular vein in baseline condition (dressage group and control group) and after exercise, within 5 minutes of the end of the training session (dressage group). Compared to baseline values, results showed higher ACTH concentrations after the first day of the first training week (P < .005) and after the third day of the second week (P < .005); higher lactate concentrations after the second and the third day of the second week (P < .01); lower glucose concentrations after the third day of the first week (P < .01); higher HR, RR, and RT values and lower PLT count after different time points during both training weeks. One-way ANOVA showed significant training effect for ACTH (F = 7.605; P < .0001) and glucose (F = 3.505; P < .001) concentrations over time points. Two-way ANOVA showed a significant effect of dressage training sessions between the first and the second week for ACTH (F = 6.508; P < .001) and cortisol (F = 5.559; P < .0001) concentrations. From obtained data, it seems that the use of ACTH and cortisol changes for the assessment of effects of training in initially 2-year-old horses could be an ideal measure of quantitative and qualitative stress responses. The quantification at the same time of functional responses to stressful stimuli may offer a more objective measurement of dressage training effects.     

Preliminary Investigation of the Area Under the l‐Lactate Concentration–Time Curve (LACAREA) in Critically Ill Equine Neonates

Background

A variety of measures of l‐lactate concentration ([LAC]) in the blood of critically ill neonatal foals have shown utility as prognostic indicators. These measures, evaluating either the severity of hyperlactatemia or the duration of exposure to hyperlactatemia, perform fairly well and have correctly classified 75–80% of foals examined in several studies. The area under the l‐lactate concentration versus time curve (LAC _Area) encompasses both severity and duration of hyperlactatemia and should improve correct classification of patient survival.

Hypothesis/Objectives

LAC _Area is larger in nonsurviving critically ill neonatal foals.

Animals

Forty‐nine foals admitted for critical illness to 1 of 4 referral hospitals.

Methods

Whole blood was obtained at admission and 6, 12, 18, and 24 hours after admission for measurement of l‐lactate using a handheld lactate meter. LAC _Area was calculated for: admission–6, 6–12, 12–18, 18–24 hours, and admission–24 hours using the trapezoidal method and summing the 6‐hours interval areas to determine total 24 hours area. Differences between survivors and nonsurvivors were determined using robust regression and Kruskal–Wallis testing, P < .05.

Results

LAC _Area was significantly larger in nonsurviving foals (n = 9) than in surviving foals (n = 40) at all time periods examined.

Conclusions and Clinical Importance

Differences in LAC _Area between surviving and nonsurviving critically ill neonatal foals are large and support further investigation of this method as an improved biomarker for survival in critically ill neonatal foals is indicated.     

Atrial Natriuretic Peptide as an Indicator of the Severity of Valvular Regurgitation and Heart Failure in Horses

Natriuretic peptides are cardiac biomarkers, routinely used for diagnosis, prognosis, and guidance for treatment in human and small animal cardiology. However, their diagnostic and prognostic value in horses has received little study. The aim of this study was to investigate the plasma atrial natriuretic concentration (ANP_Pl) in a large group of horses with various degrees of valvular regurgitation (VR) and congestive heart failure (CHF). Clinical examination and two-dimensional time-motion mode and Doppler echocardiography were performed on 91 horses admitted to the Equine Teaching Hospital of Liege University, with either no, mild, moderate, or severe VR and presenting various stages of CHF. Plasma atrial natriuretic concentration was measured using a commercially available human radioimmunoassay test. Mean values of body weight, age, ANP_Pl, and echocardiographic parameters were compared among horses with no, mild, moderate, and severe VR and among horses in different CHF stages. Correlation and linear regression of ANP_Pl with each echocardiographic parameter and with the percentage of dilation of each of cardiac chambers were assessed. Horses with severe or moderate VR had significantly higher ANP_Pl than those with mild or no VR. Plasma atrial natriuretic concentration was significantly higher in horses presenting CHF than those without CHF. Plasma atrial natriuretic concentration was significantly correlated with the left atrial diameter and its percentage of dilation. These results suggest a diagnostic value of ANP_Pl in horses with VR, especially with tricuspid or mitral insufficiency with dilation of the atria.     

Cardiac troponin I in dogs anaesthetized with propofol and sevoflurane: the influence of medetomidine premedication and inspired oxygen fraction

Objective

To investigate changes in serum cardiac troponin I (cTnI) concentrations in dogs in which medetomidine was used for sedation or for premedication prior to anaesthesia with propofol and sevoflurane.

The Influence of High‐Intensity Moderate Duration Exercise on Cardiac Troponin I and C‐Reactive Protein in Sled Dogs

Background: C‐reactive protein (CRP) and cardiac troponin I (cTnI) are biomarkers of systemic inflammation and cardiac damage, respectively. Objective: To investigate the effects of short‐duration high‐intensity exercise on plasma cTnI and serum CRP concentrations in sprint racing sled dogs. Animals: Twenty‐two Alaskan sled dogs of 2 different teams participating in a 2‐day racing event. Methods: In this prospective field study, cephalic venipuncture was performed on all dogs before racing and immediately after racing on 2 consecutive days. Plasma cTnI and serum CRP concentrations were evaluated at each time point. Results: There was a mild, significant rise (P < .01) in median cTnI concentrations from resting (0.02 ng/mL; 0.0–0.12 ng/mL) on both days after racing (day 1 = 0.06, 0.02–0.2 ng/mL; day 2 = 0.07, 0.02–0.21 ng/mL). Serum CRP concentrations showed a mild significant increase (P < .01) on day 2 after racing mean (9.2 ± 4.6 μg/mL) as compared with resting (6.5 + 4.3 μg/mL) and day 1 after racing (5.0 + 2.9 μg/mL). Neither cTnI or CRP concentrations exceeded the upper reference range for healthy dogs. Conclusions and Clinical Relevance: Strenuous exercise of short duration did not result in cTnI concentrations above the reference range for healthy dogs. Although increased after 2 days of short‐duration strenuous exercise, CRP did not reach concentrations suggestive of inflammation, as reported previously in the endurance sled dogs. Therefore, we surmise that moderate exercise does not present a confounding variable in the interpretation of cTnI and CRP concentrations in normal dogs.     

籽鹅生长期部分血液激素含量及IGF-I mRNA表达量的研究

试验选择健康1日龄籽鹅100只，相同条件下饲养到12周龄。分析血清中IGF—I、T3和T4变化规律。同时，利用RT—PCR技术研究IGF-I mRNA在不同组织中的表达量变化。结果表明：血清IGF—I水平在出生后30d内都较高，30日龄与其他日龄相比差异均显著（P〈0．05）；T3水平在出生时最高，60日龄时低于其他各日龄（P〈0．05）；T4水平出生时显著低于其他各日龄（P〈0．05）；肝脏中IGF—I mRNA在30日龄表达量极显著高于其他各日龄（P〈0．05）；30日龄各组织中IGF-I mRNA以肝脏和生殖器官表达量最高。     

Clinicopathologic features and outcome predictors of Leptospira interrogans Australis serogroup infection in dogs: a retrospective study of 20 cases (2001-2004)

BACKGROUND AND HYPOTHESIS: We retrospectively evaluated the clinicopathologic findings and outcome predictors in dogs with Leptospira interrogans Australis serogroup infections. ANIMALS AND METHODS: The medical records of 159 dogs that had a leptospiral microscopic agglutination test (MAT) performed between 2001 and 2004 were reviewed. RESULTS: Twenty dogs met serologic criteria for either symptomatic (16 dogs) or asymptomatic (4 dogs) infection caused by Leptospira interrogans Australis serogroup. Seven of 16 symptomatic dogs died or were euthanized and 9/16 recovered. Systemic inflammatory response syndrome (SIRS) was observed in 9/16 dogs. The presence of SIRS did not affect prognosis (P = .357). C-reactive protein (CRP) and haptoglobin (Hpt) concentrations were altered in all symptomatic dogs, but results did not differ significantly between survivors and nonsurvivors (P = .08 and P = .055, respectively). Conversely, the CRP to Hpt ratio (CRP/Hpt) was significantly increased in nonsurvivors. Disseminated intravascular coagulation (DIC) was diagnosed in 7/16 dogs. DIC did not significantly affect outcome (P = .126). Multiple organ involvement was present with renal failure in 16/16, liver damage in 12/16, cardiac damage in 11/16, and muscular damage in 8/16 dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Among the evaluated clinicopathologic biomarkers, serum albumin, cardiac troponin I, CRP/Hpt, urinary albumin, and urinary total protein to creatinine ratio were found to predict outcome and warrant evaluation in larger prospective studies.     

Competition Horses Housed in Single Stalls (II): Effects of Free Exercise on the Behavior in the Stable, the Behavior during Training, and the Degree of Stress

Although housing horses in single stalls limits their natural behavior to a great extent, this housing system is widespread in Germany, especially for competition horses. To improve the welfare of this system, free exercise on pastures or paddocks is deemed suitable, but it is also feared because of injuries and decreased willingness or motivation to perform. In the present study, three treatments were investigated with regard to their effect on the behavior of six competition horses in the stable, behavior during training, and on their degree of stress: daily training without free exercise (no turnout [NT]), solitary turnout for 2 hours after training, and 2-hour turnout in groups of two after training (group turnout). The horses’ behavior in the stable was continuously analyzed through video recordings (2 pm to 6 am) on 3 days at the end of each treatment. The degree of stress was evaluated daily by heart rate variability at rest. The behavior during training was evaluated by a questionnaire answered by the riders, and the distance covered during training was measured by global positioning system. When NT was allowed, the horses showed less lying in the stable compared with the treatments with turnout. Heart rate variability measurements resulted in great individual differences, but generally, there was a higher degree of stress shown with the treatment NT according to the following parameters: standard deviation of inter-beat-intervals (SDNN), square root of the mean of the sum of the squares of differences between successive inter-beat-intervals (RMSSD), and ratio between low frequency and high frequency (LF/HF). The willingness to perform was evaluated as being slightly better in the treatments with turnout than in the treatment without turnout.     

Preliminary Observations on the Concentrations of Serum Luteinizing Hormone and Follicle-stimulating Hormone during Gestation in Bactrian Camels (Camelus bactrianus)

The concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in the serum of the Bactrian camel (Camelus bactrianus) throughout pregnancy were analysed by radioimmunoassay. The samples were withdrawn at intervals of half a month. The serum LH concentrations varied significantly between 2.2±0.9 and 20.3±18.8 ng/ml during the pregnancy, with the highest value on the day of artificial insemination, which indicated that a preovulatory LH peak appeared. Thereafter, the LH concentration tended to fall, reaching a fairly constant low level by the eighth month of pregnancy. The serum FSH concentrations varied between 7.0±0.2 and 28.9±0.4 ng/ml during gestation, with the peak value being reached at 4.5 months, followed by a marked drop to 7.0±0.2 ng/ml at 7.5 months.     

Studies on growth cartilage in the horse and their application to aetiopathogenesis of dyschondroplasia (osteochondrosis)

The importance of osteochondrosis (dyschondroplasia) to the horse industry has been well documentedsince it was first recorded 50 years ago. The condition is known to be multifactorial in origin, arising from focal failure of endochondral ossification at predilection sites in articular/epiphyseal growth cartilage, but specific information on its aetiopathogenesis is sparse. This paper reviews the current knowledge of growth cartilate metabolism and the process of normal endochondral ossification in the horse. It highlights the localization of various protein products of chondrocytes and the differences in the zones of articular cartilage. In the early focal lesions (referred to as dyschondroplasia) there are alterations in the chondrocytes, extracellular matrix and some of the local protein products. The most obvious feature is an alteration in matrix metabolism which may be responsible for triggering a range of other factors leading to the development of a retained core of cartilage and a primary lesion of dyschondroplasia.Based on available evidence, a preliminary hypothesis for pathogenesis is presented. This suggests thatthere are a number of factors capable of initiating the condition. One of these involves high circulating insulin levels from high energy feeding which may affect chondrocyte maturation leading to altered matrix metabolism and faulty mineralization resulting in the formation of cartilage cores which characterize the condition. Further research to test this hypothesis is needed before there can be a rational basis for prophylaxis.