Severity Of Exercise-induced Pulmonary Haemorrhage Research Articles

Racetrack exercise vs treadmill exercise with respect to exercise-induced pulmonary haemorrhage (EIPH): implications for studies of putative treatments of EIPH

Multiple treadmill-based studies using low numbers of horses have evaluated potential prophylactic treatments for exercise-induced pulmonary haemorrhage (EIPH) and found no effect. However, the relevance of these findings to racing is unclear. Because severity of EIPH incurred on treadmills has not been compared to that following high-speed racetrack exercise in the same horses, we retrospectively performed this comparison using bronchoalveolar lavage fluid red cell numbers (BALFRBC) due to the relative insensitivity of tracheobronchoscopy. Six race-fit Thoroughbreds with recent tracheobronchoscopic EIPH scores ≥2 were exercised to fatigue on a treadmill at 115% V̇O2max (5% incline, 12.3-14.2 m/s), and maximally on a racetrack over 800 m and 1,100 m with average speeds ranging from 16.4-16.7 and 15.5-16.6 m/s, respectively. Run order varied but was not randomised. Bronchoalveolar lavage (BAL) was performed blindly using Bivona tubes 45-60 mins post-exercise. BALFRBC were determined using a haemocytometer. Data were expressed as median and interquartile range, and analysed using RM ANOVA with significance set at P<0.05. BALFRBC were greater after both racetrack runs than after treadmill exercise (P<0.05; treadmill: 10,305/μl (3,871-26,079); 800m: 25,000/μl (17,175-73,400); 1,100m: 19,500/μl (8,962-800,600). Treadmill exercise resulted in lower numbers and a narrower range in BALFRBC than racetrack exercise. Thus, when a small number of horses is used to study EIPH treatments on a treadmill, a lower BALFRBC would be anticipated following the baseline run than with a similar study using racetrack exercise, and might reduce the likelihood of demonstrating significant treatment effects. Results of this retrospective study raise concern regarding the advisability of extrapolating conclusions regarding efficacy of EIPH treatments from treadmill studies to racetrack scenarios.

The application impact of an origanum, anise and citrus oils blend in horses nutrition

DOI: 10.15414/afz.2015.18.04.103–105 Received 1. July 2015 ǀ Accepted 28. August 2015 ǀ Available online 7. December 2015 The aim of the paper was to analyse the origanum, anise and citrus oils blend as a potential phytogenic feed additive in horse’s nutrition. Several studies in the World analyze the effect of plant origin aromatic additives on blood serum indicators and nutrients digestibility in horses. Origanum and anise contains many chemical compounds as carvacrol, thymol and anethol, which can be beneficially in metabolism and nutrients digestion. Some studies shows, that these additives have insignificant (P>0.05) effect on blood serum indicators, but there are some studies, which reported positive significant (P<0.05) effect on serum cholesterol and triglycerides contents. The main positive effect of origanum and anise is in nutrients digestibility improving. These herbs can improve the digestibility of dry matter, organic matter, nitrogen free extract, crude fibre, ADV and NDV (P<0.05), as well as Mg and K from feed rations (P<0.05). Some antagonistic results published in this area can be affecting in dosage of active compounds, which have often antinutritive effects. Keywords : equine, additives, aromatic plants, feed rations References CAPCAROVA, M. and KOLESAROVA, A. (2010) Beneficial substances affecting internal milieu of animals. Nitra: Slovak University of Agriculture. EPP, T.S. et al. (2005) The effect of herbal supplementation on the severity of exercise-induced pulmonary haemorrhage. In J. Equine and Comp. Exerc. Physiol., vol. 2, pp. 17-25. FORS, M. 2009. Herbs for horses. Uppsala: Swedish University of Agricultural Science. GALIK, B. et al. (2011) The effect of phytoadditives on macroelements digestibility of sport horses. In J. Centr. Europ. Agricul., vol. 12, pp. 390-397. DOI:http://dx.doi.org/10.5513/JCEA01/14.3.1308 GALIK, B. et al. (2012a) The effect of phytogenic additive on in vivo saccharides digestibility of sport horses. In Pharm. Comm., vol. 2, pp. 3-6. DOI: http://dx.doi.org/10.5530/pc.2013.1.2 GALIK, B. et al. (2012b) The effect of different macromineral intakes on mineral metabolism of sport horses. In Acta Vet. Brno, vol. 81, pp. 113-117. DOI: http://dx.doi.org/10.2754/avb201281020113 GALIK, B. (2012c) The effect of fytogenic feed addtives on nutrients utilization in non-ruminants: Assoc. Prof. thesis. Nitra: Slovak University of Agriculture (in Slovak) GALIK, B. et al. (2013) The effect of phytoadditives on biochemical indicators and nutrients digestibility in sport horses. In J. Centr. Europ. Agricul., vol. 14, pp. 219-227. DOI: http://dx.doi.org/10.5513/JCEA01/14.3.1308 KAMEL, C. (2000) Natural plant extracts: Classical remedies bring modern animal production solutions. In Proceedings of the 3rd Conference on sow feed manufacturing in the Mediterranean region, Reus, March 22-24, 2000. Reus: Spain, pp. 31-38. MORGAN, L.M. et al. (2007) Effect of yeast culture supplementation on digestibility of varying forage quality in mature horses. In J. Equine Vet. Sci., vol. 27, pp. 260-265. PEARSON, W. et al. (2007) Pilot study investigating the ability an herbal composite to alleviate clinical sings of respiratory dysfunction in horses with recurrent airway obstruction. In Can. J. Vet. Res., vol. 71, pp. 145-151. STRAKOVA, E. et al. (2007) Positive effect of plant-based diet on the performance and health of laying hens. In Acta Vet. Brno, vol. 76,pp. 31-37. DOI: http://dx.doi.org/10.2754/avb200776S8S031 STEINER, T. (2006) Managing gut health: Natural growth promoters as a key to animal performance. Nottingham: Nottingham University Press. Steiner, T. (2009) Phytogenics in animal nutrition: Natural concepts to optimize gut health and performance. Nottingham: Nottingham University Press. SUCHÝ, P. et al. (2002) Replacement of animal origin feed by plant origin feed in the diet of broiler chickens. In Czech J. Anim. Sci., vol. 47, pp. 365-373. TURNER, K.K. et al. (2006) Bee pollen product supplementation to horses in training seems to improve feed intake: a pilot study. In J Anim. Physiol. Nutr., vol. 90, pp. 414-420. DOI: http://dx.doi.org/10.1111/j.1439-0396.2006.00621.x WINDISH, W. et al. (2008) Use of phytogenic products as feed additives for swine and poultry. In J. Anim. Sci., vol. 86, pp. 140-148. DOI: http://dx.doi.org/10.2527/jas.2007-0459. ZENG, Z. et al. (2015) Essential oil and aromatic plants as feed additives in non-ruminant nutrition: a review. In J. Anim. Sci. Biotech, vol. 6, pp. 1-10. DOI: http://dx.doi.org/10.1186/s40104-015-0004-5

Bar shoes and ambient temperature are risk factors for exercise-induced pulmonary haemorrhage in Thoroughbred racehorses.

Ambient temperature has been identified as a risk factor for exercise-induced pulmonary haemorrhage (EIPH) in racing Thoroughbreds. This warranted a more expansive investigation of climatic conditions on the incidence and severity of EIPH. The impact of other variables such as the type of bit used, tongue ties and nonstandard shoes has not been reported and also warrant investigation. To examine the effect of various climatic variables as contributing risk factors for EIPH. Other previously uninvestigated variables as well as standard track and population factors will also be examined. Cross-sectional study. Thoroughbred racehorses competing at metropolitan racetracks in Perth, Western Australia were examined 30-200min post race with tracheobronchoscopy. Examination took place at 48 race meetings over a 12month period. Examinations were graded (0-4), independently by two experienced veterinarians. Univariable analyses were performed and variables with a P<0.25 were entered into a multivariable logistic regression analysis. The analysis was performed twice using the presence of blood (EIPH grade 0 vs. grades ≥1) and EIPH grades ≤1 vs. EIPH grades ≥2 as dependent variables. Exercise-induced pulmonary haemorrhage was diagnosed in 56.6% of observations. Lower ambient temperature was significantly associated with EIPH grades ≥1 (OR 0.95; 95% CI 0.93-0.98) and EIPH grades ≥2 (OR 0.97; 95% CI 0.94-1.0). Bar shoes were significantly associated with EIPH grades ≥1 (OR 6.35; 95% CI 2.17-18.54) and EIPH grades ≥2 (OR 2.72; 95% CI 1.3-5.68). Increasing race distance was significantly associated with EIPH grade ≥1 and increasing lifetime starts was significantly associated with EIPH grade ≥2. Ambient temperature is a risk factor for EIPH in Thoroughbred racehorses, with lower temperatures associated with increased risk. Bar shoes are a novel risk factor for EIPH in this population.

A systematic review and meta-analysis of the efficacy of furosemide for exercise-induced pulmonary haemorrhage in Thoroughbred and Standardbred racehorses.

Furosemide is the most commonly used medication for exercise-induced pulmonary haemorrhage (EIPH); however, critical evaluation of the strength of evidence for efficacy of furosemide is lacking and is warranted so that evidence-based treatment decisions can be made. To evaluate the efficacy of furosemide to reduce the severity or frequency of detection of EIPH in Thoroughbred and Standardbred racehorses. Systematic review with meta-analyses. Primary studies were identified via searches of electronic databases, relevant texts and reference lists of published articles. Studies were not restricted by date or publication status. Only studies published in English were eligible for inclusion. Searches were performed using a predetermined search string. Randomised controlled trials, nonrandomised trials and observational studies were included. Three authors independently assessed each study using the Cochrane collaboration guidelines and Grading of Recommendations Assessment, Development and Evaluation recommendations for rating quality of evidence. Meta-analysis of studies was performed with pooled data to determine whether furosemide reduced the frequency of detection of EIPH (yes or no) as evaluated by tracheobronchoscopy or bronchoalveolar lavage fluid red blood cell number, or if furosemide reduced the severity of EIPH by at least one tracheobronchoscopic grade. Seventeen studies fulfilled the inclusion criteria. The relative risk of detecting any EIPH by tracheobronchoscopy after administration of furosemide was 0.88 (pooled data from 11 studies, n = 5780; 95% confidence interval 0.79-0.97, P = 0.01). When data from only high-quality randomised controlled trials (2 studies, n = 405) were used, the relative risk of detecting endoscopically evident EIPH was 0.68 (95% confidence interval 0.58-0.79, P<0.001). The proportion of horses previously diagnosed with EIPH having a reduction of at least one EIPH grade after furosemide was 68% (2 studies, n = 405; 95% confidence interval 61-78%). There is high-quality evidence, albeit limited, that administration of furosemide reduces the incidence and severity of EIPH in Thoroughbred or Standardbred racehorses.

Prospective study of the association between exercise‐induced pulmonary haemorrhage and long‐term performance inThoroughbred racehorses

Exercise-induced pulmonary haemorrhage (EIPH) is associated with impaired short-term race performance but consequences to long-term race performance of Thoroughbred racehorses are unknown. Knowledge of effects of EIPH on performance over a prolonged time would inform the need for management and treatment of this disorder. To determine the relationship between EIPH detected on a single occasion and long-term athletic performance in Thoroughbred racehorses. Prospective, longitudinal, observational epidemiological study conducted from 2003 to 2012. Seven hundred and forty-four Thoroughbred racehorses underwent a single tracheobronchoscopic examination to determine presence and severity of EIPH in 2003. Following retirement of all the horses from racing, career after examination and lifetime performance data (including career duration, earnings, starts, wins and placings) were abstracted from a commercial database. The association between presence and severity of EIPH and individual performance variables were analysed using survival analysis, linear regression and negative binomial regression. No association was detected between the presence of any EIPH (grade ≥1) and all measures of long-term performance examined except that horses with EIPH (grade ≥2) had fewer earnings after endoscopic examination than did horses with mild EIPH or no EIPH (grades ≤1). Multiple associations were detected between the most severe form of EIPH (grade 4) and measures of long-term performance suggesting that the severity of EIPH commonly associated with epistaxis adversely affects either the horse's opportunity to race or physiologic capacity to race. We conclude that there is no association between EIPH grades 0, 1, 2 and 3 and long-term racing performance of Thoroughbred racehorses. These results are based on a single endoscopic evaluation of EIPH grade made during a horse's career. Further studies are required to determine the reasons for an association of severe (grade 4) EIPH with impaired long-term race performance.

Effects of intravenous aminocaproic acid on exercise‐induced pulmonary haemorrhage (EIPH)

The antifibrinolytic, 6-aminohexanoic acid, also named aminocaproic acid (ACA), has been used empirically as a treatment for exercise-induced pulmonary haemorrhage (EIPH) on the unsubstantiated basis that transient coagulation dysfunction may contribute to its development. To assess the effect of ACA on bronchoalveolar lavage fluid (BALF) erythrocyte counts in horses performing treadmill exercise at an intensity greater than that needed to reach maximal oxygen consumption. Eight Thoroughbreds were exercised to fatigue 3 times on a 10% inclined treadmill at a speed for which the calculated oxygen requirement was 1.15 times VO2max. Horses were treated with a saline placebo, 2 and 7 g ACA i.v. 4 h before exercise, with a crossover design being used to determine the order of the injections. Exercise-induced pulmonary haemorrhage severity was quantified via the erythrocyte count in BALF. Bronchoalveolar lavage fluid was collected 4 h before and 30-60 min post exercise. Results were expressed as mean ± s.e.m. and analysed by one way repeated measures ANOVA (P < 0.05). Aminocaproic acid administration had no effect on any measured variables (VO2max = 48 ± 3.0 [C]; 148 ± 3.0 [2 g ACA]; 145 ± 3.0 [7 g ACA] ml/kg bwt/min, respectively; run time = 77 ± 3 [C]; 75 ± 2 [2 g ACA]; 79 ± 3 [7 g ACA] seconds, respectively). All horses developed EIPH: 1691 ± 690 vs. 9637 ± 3923 (C); 2149 ± 935 vs. 3378 ± 893 (2 g ACA); 1058 ± 340 vs. 4533 ± 791 (7 g ACA) erythrocytes/µl pre- vs. post exercise recovered in BALF, respectively. Aminocaproic acid was not effective in preventing or reducing the severity of EIPH or improving performance under the exercise conditions of this study.

Pulmonary response to airway instillation of autologous blood in horses

Exercise-induced pulmonary haemorrhage (EIPH) occurs in the majority of horses performing strenuous exercise. Associated pulmonary lesions include alveolar and airway wall fibrosis, which may enhance the severity of EIPH. Further work is required to understand the pulmonary response to blood in the equine airways. To confirm that a single instillation of autologous blood into horse airways is associated with alveolar wall fibrosis, and to determine if blood in the airways is also associated with peribronchiolar fibrosis. Paired regions of each lung were inoculated with blood or saline at 14 and 7 days, and 48, 24 and 6 h before euthanasia. Resulting lesions were described histologically and alveolar and airway wall collagen was quantified. The main lesion observed on histology was hypertrophy and hyperplasia of type II pneumocytes at 7 days after blood instillation. This lesion was no longer present at 14 days. There were no significant effects of lung region, treatment (saline or autologous blood instillation), nor significant treatment-time interactions in the amount of collagen in the interstitium or in the peribronchial regions. A single instillation of autologous blood in lung regions is not associated with pulmonary fibrosis. Pulmonary fibrosis and lung remodelling, characteristic of EIPH, are important because these lesions may enhance the severity of bleeding during exercise. A single instillation of autologous blood in the airspaces of the lung is not associated with pulmonary fibrosis. Therefore the pulmonary fibrosis described in EIPH must have other causes, such as repetitive bleeds, or the presence of blood in the pulmonary interstitium in addition to the airspaces. Prevention of pulmonary fibrosis through therapeutic intervention requires a better understanding of these mechanisms.

The effect of herbal supplementation on the severity of exercise-induced pulmonary haemorrhage

AbstractExercise-induced pulmonary haemorrhage (EIPH) is a serious condition that affects the health and possibly the performance of all racehorses. However, only two treatments, furosemide and the Flair™ equine nasal strip, both of which reduce capillary transmural pressure, have been successful in reducing EIPH. Alternatively, transient impairment of platelet function and coagulation during exercise has been considered an additional contributor to EIPH. Consequently, herbal formulations designed to enhance platelet function, and hence coagulation, are hypothesized to reduce EIPH. To investigate the validity of this hypothesis, five Thoroughbred horses completed three maximal incremental exercise tests on a 10% inclined treadmill in a randomized cross-over design experiment. Treatments included twice daily oral administration (for 3 days) of a placebo (PL; cornstarch) and two herbal formulas, Yunnan Paiyao (YP) or Single Immortal (SI). Blood samples for coagulation profiles, complete blood counts and biochemistry profiles were collected before each exercise test. During each test, pulmonary arterial pressure, oxygen uptake, arterial blood gases, plasma lactate and time-to-fatigue were measured. Severity of EIPH was quantified via bronchoalveolar lavage (BAL) at 30–60 min post-exercise. The herbal formulations were not effective in decreasing EIPH (×106 red blood cells ml−1 BAL fluid: PL, 27.1±11.6; YP, 33.2±23.4; SI, 35.3±15.4, P&gt;0.05) or in changing any of the other variables measured with the exception of time-to-fatigue, which was slightly but significantly prolonged by Single Immortal compared with placebo and Yunnan Paiyao (PL, 670±9.6 s; YP, 665±5.5 s; SI, 685±7.9 s, P&lt;0.05). Thus, these results do not support the use of these herbal formulations in the prevention of EIPH.

Pulmonary vascular pressures of thoroughbred horses exercised 1, 2, 3 and 4 h after furosemide administration.

Furosemide premedication of horses 4 h prior to exercise significantly attenuates exercise-induced pulmonary capillary hypertension which may help diminish the severity of exercise-induced pulmonary haemorrhage. As pulmonary hemodynamic effects of furosemide may be mediated via a reduction in plasma volume (which is most pronounced 15-30 min postfurosemide administration, with plasma volume recovering thereafter), we hypothesized that administration of furosemide at intervals shorter than 4 h before exertion may be more effective in attenuating the exercise-induced rise in pulmonary capillary blood pressure. Thus, our objective was to determine whether furosemide-induced attenuation of exercise-induced pulmonary arterial, capillary and venous hypertension would be enhanced when the drug is administered at intervals shorter than 4 h before exercise. Using established techniques, right atrial, and pulmonary arterial, capillary and wedge (venous) pressures were ascertained in seven healthy, sound, exercise-trained Thoroughbred horses in a randomized split-plot experimental design. Measurements were made at rest and during exercise performed at maximal heart rate (217 +/- 3 beats/min) in the control (no medications) experiments and following furosemide administration (250 mg intravenously (i.v.)) at 1, 2, 3 and 4 h before exercise. Sequence of treatments was randomized and 7 days were allowed between experiments on each horse. Although furosemide administration in the four treatment groups caused only insignificant changes in the pulmonary arterial, capillary and wedge pressures of standing horses, furosemide-induced reduction in mean right atrial pressure achieved statistical significance in the 2 h postfurosemide experiments. In the control studies, exercise was attended by statistically significant increments in mean right atrial, as well as pulmonary arterial, capillary and wedge pressures. Although exercise in each of the four furosemide experiments was also attended by significant increments in right atrial as well as pulmonary vascular pressures, in the 1, 2 and 3 h postfurosemide experiments, mean right atrial pressure increased to a significantly lower value than in the control study. Exercise-induced changes in pulmonary vascular pressures in the 1 h postfurosemide experiments were not different from the pressures in the control study. There was a significant attenuation of exercise-induced pulmonary capillary and venous hypertension in the 2, 3 and 4 h postfurosemide experiments, but significant differences among these treatments were not found. Thus, these data did not support the contention that administration of furosemide at intervals shorter than 4 h before exercise is more effective in attenuating exercise-induced pulmonary capillary or venous hypertension in Thoroughbred horses.

Frusemide

SummaryFrusemide is administered to large numbers of North American racehorses because of its putative prophylactic effect on exercise induced pulmonary haemorrhage (EIPH). Two issues central to the use of frusemide in performance horses remain to be resolved: 1) Does frusemide reduce the incidence or severity of EIPH? and 2) does frusemide alter athletic performance or the capacity for muscular work, separate from any effect on EIPH? These issues are discussed, as is the reasoning that EIPH is, at least in part, a consequence of exertion induced high vascular transmural pressures and that reduction of these pressures by frusemide is the mechanism by which frusemide reduces the incidence or severity of EIPH. It is concluded that, on balance, it appears unlikely that frusemide reduces the incidence of EIPH, although it may reduce the severity of haemorrhage. The evidence that frusemide is ergogenic is evaluated and a potential mechanism for an effect of frusemide on athletic capacity, the frusemide induced reduction in body weight, is discussed.

Equine bronchoalveolar lavage cytology: survey of thoroughbred racehorses in training.

Sixty-two Thoroughbred horses aged between 1 and 7 years in training in Sydney had bronchoalveolar lavage (BAL) samples collected for cytological examination. All horses, except the yearlings and those with a cough, had raced at the time of the examination and the trainers reported satisfactory performance. Free erythrocytes were found in 73% of samples and haemosiderophages in 90% of the samples, indicating immediate or past occurrences of exercise-induced pulmonary haemorrhage (EIPH). Bronchoalveolar fluid from the yearlings contained significantly less (P < 0.05) erythrocytes and haemosiderophages than samples from horses in other age groups. In the older horses, there was also more haemosiderin within the macrophages. No differences in BAL cytology could be attributed to gender, and there was no relationship between BAL cytology and racing performance. The main cytological findings were (mean +/- sd): total nucleated cells--832 +/- 578/microL with the main cell types being: macrophages--59 +/- 10% (haemosiderophages--20 +/- 24%); neutrophils--9 +/- 6%; lymphocytes--31 +/- 9%. The erythrocyte count was 10.3 +/- 17.7% of the total cell count. Horses with chronic coughing had a higher proportion of macrophages and a lower proportion of lymphocytes in the leucocytes obtained from BAL. There was a higher occurrence of EIPH detected in BAL findings than that previously reported when endoscopic examination has been used to diagnose EIPH. The occurrence and severity of EIPH as indicated by the BAL findings was found to be related to exercise intensity. The cytological findings were similar to those reported in horses in the northern hemisphere.(ABSTRACT TRUNCATED AT 250 WORDS)