Impact of training and exercise intensity on blood antioxidant markers in healthy Standardbred horses

in Equine & Comparative Exercise Physiology (2004), 1(3), 211-220

This study investigated the effect of training and exercise intensity on blood antioxidant markers in six healthy Standardbred horses. Markers studied were uric acid (UA), ascorbic acid (AA), α-tocopherol ... [more ▼]

This study investigated the effect of training and exercise intensity on blood antioxidant markers in six healthy Standardbred horses. Markers studied were uric acid (UA), ascorbic acid (AA), α-tocopherol, vitamin A (Vit A), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione – reduced (GSH) and oxidized (GSSG), glutathione redox ratio (GRR), copper (Cu), zinc (Zn) and selenium (Se). The horses performed a standardized exercise test (SET) when they were untrained (T0), after 4 weeks of light training (T4) and after 8 weeks of interval training (T12). Forty-eight hours after SET T4 and SET T12, a SET with run up to fatigue (TTF4 and TTF12) was performed. Maximal oxygen consumption (V˙O2max) was determined within 3–5 days after TTF4 and TTF12. At each test (SET T(i) and TTF(i)), venous blood was sampled at rest (R), peak-exercise (Emax), 15 (E15) and 60 (E60) min after the test. UA, AA and GRR were increased significantly by the exercise, whereas GSH and Vit A were decreased significantly (P<0.05). Training-related increases (T0 vs. T4 vs. T12) were observed for UA, SOD, GPx and Se, whereas GSH, α-tocopherol and Zn decreased (P<0.05). Exercise intensity (TTF(i) vs. T(i)) increased UA and AA significantly and decreased GSH significantly (P<0.05). A significant correlation between ΔSOD and ΔV˙O2max (r=0.86, p<0.05) determined at SET T4 and SET T12 was found. Taken together, these results indicate that training and exercise intensity significantly influence blood antioxidant markers in healthy Standardbred horses [less ▲]

Functional effects of restrictive pulmonary diseases

in Dunlop, R. H.; Malbert, C. H. (Eds.) Veterinary Pathophysiology (2004)

Spécificités cardiorespiratoires des ânes

in Proceedings: Congrès de l'Association Vétérinaire Equine Française (AVEF) (2004)

A group of 22 donkeys underwent a series of non-invasive cardiorespiratory tests in order to establish the reference standards for this species and compare the results with those for horses. For ... [more ▼]

A group of 22 donkeys underwent a series of non-invasive cardiorespiratory tests in order to establish the reference standards for this species and compare the results with those for horses. For particular tests (haematology, measurement of arterial blood gases, electrocardiogram width phonocardiogram, thoracic radiographs, cardiac echocardiography), no major différences were found. However, the mechanical ventilation parameters differed from those for horses and were similar to those for food-producing animals (cattle). The conformation of the pharynx and larynx is slightly différent to that of horses making it more difficult to pass an endoscope through this area. The differencial leukocyte count from tracheal lavage includes a number of epithelial cells, and a higher percentage of eosinophils and neutrophils for donkeys compared to horses. These similarities and différences between donkeys and horses should be taken into account when performing ancillary tests. [less ▲]

Use of the impulse oscillometry system for testing pulmonary function during methacholine bronchoprovocation in horses.

in American Journal of Veterinary Research (2003), 64(11), 1414-1420

OBJECTIVE: To compare sensitivity of the impulse oscillometry system (IOS) with that of the conventional reference technique (CRT; ie, esophageal balloon method) for pulmonary function testing in horses ... [more ▼]

OBJECTIVE: To compare sensitivity of the impulse oscillometry system (IOS) with that of the conventional reference technique (CRT; ie, esophageal balloon method) for pulmonary function testing in horses. ANIMALS: 10 horses (4 healthy; 6 with recurrent airway obstruction [heaves] in remission). PROCEDURE: Healthy horses (group-A horses) and heaves-affected horses (group-B horses) were housed in a controlled environment. At each step of a methacholine bronchoprovocation test, threshold concentration (TC(2SD); results in a 2-fold increase in SD of a value) and sensitivity index (SI) were determined for respiratory tract system resistance (R(rs)) and respiratory tract system reactance (X(rs)) at 5 to 20 Hz by use of IOS and for total pulmonary resistance (RL) and dynamic lung compliance (C(dyn)), by use of CRT. RESULTS: Bronchoconstriction resulted in an increase in R(rs) at 5 Hz (R(5Hz)) and a decrease in X(rs) at all frequencies. Most sensitive parameters were X(rs) at 5 Hz (X(5Hz)), R(5Hz), and R(5Hz):R(10Hz) ratio; RL and the provocation concentration of methacholine resulting in a 35% decrease in dynamic compliance (PC(35)C(dyn)) were significantly less sensitive than these IOS parameters. The TC(2SD) for X(rs) at 5 and 10 Hz was significantly lower in group-B horses, compared with group-A horses. The lowest TC(2SD) was obtained for X(5Hz) in group-B horses and R(5Hz) in group-A horses. CONCLUSIONS AND CLINICAL RELEVANCE: In contrast to CRT parameters, IOS parameters were significantly more sensitive for testing pulmonary function.The IOS provides a practical and noninvasive pulmonary function test that may be useful in assessing subclinical changes in horses. [less ▲]

Effets fonctionnels respiratoires induits par l'inhalation de glycopyrrolate chez le cheval poussif en crise

in Pratique Vétérinaire Equine (2003), 35(139), 23-29

An acute respiratory attack with bronchospasm is associated with excessive stimulation of the parasympathic nervous system. It may be reduced by administration of anticholinergic agents. Atropine and ... [more ▼]

An acute respiratory attack with bronchospasm is associated with excessive stimulation of the parasympathic nervous system. It may be reduced by administration of anticholinergic agents. Atropine and ipratropium bromide have been tested. This study is to evaluate the efficacy of the synthetic antimuscarinic compound glycopyrrolate as a bronchodilator in horses. Respiratory crisis was induced in seven allergic horses by exposure to natural allergens. Prior to the study, it was established that the attack could be stopped using intravenous atropine sulphate. Pulmonary function tests (ventilation and arterial blood gas analysis) were performed on the horses before and then after aerosol administration of 1500 µg of glycopyrrolate (Robinul®). The attack was characterised by an increase in total pulmonary resis¬tance and maximum pleural pressure variation and by decreased compliance. This study demonstrates that glycopyrrolate exhibits affects that are just as rapid and effective as intravenous atropine or aerosol administration of 1200 µg dry powder Ipratropium. In addi¬tion the treatment was well tolerated and no side-effects were observed in contrast to those seen with intravenous administration of atro¬pine. Therefore this drug has an important role to play among the therapeutics available to practitioners for acute respiratory attacks in horses [less ▲]

Effets fonctionnels respiratoires induits par l’inhalation du glycopyrrolate chez le cheval poussif en crise.

in Congrès de l'Association Vétérinaire Equine Française (AVEF) (2003)

Sternal recumbency or suspension by the hind legs immediately after delivery improves respiratory and metabolic adaptation to extra uterine life in newborn calves delivered by caesarean section.

in Veterinary Research (2002), 33(6), 709-724

The aim of this study was to evaluate the effect of body positioning immediately after delivery on respiratory and metabolic adaptation to extra-uterine life in newborn calves. One hundred and one Belgian ... [more ▼]

The aim of this study was to evaluate the effect of body positioning immediately after delivery on respiratory and metabolic adaptation to extra-uterine life in newborn calves. One hundred and one Belgian White and Blue calves were delivered at term by an elective caesarean section and were assigned into three categories according to the body position imposed immediately after umbilical cord rupture: 71 calves were placed in lateral recumbency; 16 calves were placed in sternal recumbency and 14 calves were suspended by the hind legs for less than 90 seconds (75 +/- 5 s). Following this initial body position, the calves were allowed to move without restraint. They were examined at birth, 5, 15, 30, 45 and 60 minutes, and 2, 3, 6, 12 and 24 hours after birth by the following measurements: physical examination, heart rate, arterial blood gas analysis, pulmonary function tests using the esophageal balloon catheter technique, arterial and venous blood acid-base balance analysis, rectal temperature, jugular venous blood sampling for the determination of blood glucose, plasma lactate and serum cortisol concentrations, haematologic variables and passive immune transfer variables. Body positioning immediately after delivery clearly influenced respiratory and metabolic adaptation to extra-uterine life in term calves delivered by an elective caesarean section. Systematic sternal recumbency and suspension by the hind legs for less than 90 seconds immediately after umbilical cord rupture had a positive functional impact on postnatal pulmonary mechanics and gas exchange and on postnatal correction of mixed acidosis present at birth, contributing in turn to an enhanced passive immune transfer. These two body positions should be encouraged to improve adaptation at birth in healthy term calves delivered by an elective caesarean section. Evaluation of possible side-effects is required before application in severely asphyxiated calves. [less ▲]

Relationship between markers of blood oxidant status and physiological variables in healthy and heaves-affected horses after exercise

in Equine Veterinary Journal. Supplement (2002), 34

Exercise-induced oxidative stress is investigated as a potential performance-limiting factor in human sports medicine. Therefore, the present study aimed to assess whether physiological variables that ... [more ▼]

Exercise-induced oxidative stress is investigated as a potential performance-limiting factor in human sports medicine. Therefore, the present study aimed to assess whether physiological variables that change with exercise intensity were correlated with blood oxidant markers in healthy and heaves-affected horses. Seven healthy horses, 8 heaves-affected in remission and 7 heaves-affected in crisis performed a standardised exercise test (SET) of stepwise increasing intensity. Variables monitored during exercise were heart rate (HR), venous plasma lactate (LA), packed cell volume (PCV) and arterial oxygen tension (PaO2). Oxidant markers (uric acid [UA], 8-iso-PGF2alpha and reduced [GSH] and oxidised glutathione [GSSG]) were analysed in venous peripheral blood sampled at rest (R), at peak-exercise intensity (Emax), 15 (E15) and 60 (E60) min after SET. There was a significant effect of heaves on oxidant markers and, therefore, correlation analyses between physiological variables and oxidant markers were performed separately per horse group. In healthy horses, UA analysed at Emax was positively correlated with LA. Furthermore, GSH analysed at Emax and E15 was positively correlated with PaO2. In healthy and heaves-affected horses in remission, GSH and GSSG determined at Emax were negatively correlated with HR. There was no significant correlation between 8-iso-PGF2alpha and physiological variables. In conclusion, a correlation between the physiological response to exercise and some oxidant markers exists in healthy horses. However, in heaves-affected horses the blood oxidant status is probably more dependant on airway disease than on exercise. Future studies should be undertaken to assess whether antioxidant supplementation might positively influence the oxidant-antiodidant balance in exercising horses. [less ▲]

Pulmonary function in the exercising horse

in Lekeux, Pierre (Ed.) Equine Respiratory Diseases, IVIS Ithaca NY (2002)

Gestion environnementale des affections respiratoires du cheval

Conference given outside the academic context (2002)