RESUMO

This study proposes the theoretical principles for the selection of a sample of horse races to study the relationship between air pollutants and performance. These criteria were then applied to an original dataset comparing the correlations between these variables obtained in "Handicap" versus "Conditional" type races. METHODS: The mean concentration of pollutants during the six hours prior to the race and the speed of the test were determined in 441 official races at a racecourse in Santiago, Chile, during the summer and winter months of 2012. Using layout, track condition and distance (1000, 1100 and 1200 m) as criteria, a homogeneous group of races ("Handicap"; n = 214) versus a heterogeneous group ("Conditional"; n = 95) were compared using simple correlations (Spearman's test). RESULTS: Race speed was related to greater levels of PM10, PM2.5, NO2, NO and SO2 and it was positively related to O3, a trend that was observed in the 1000, 1100 m races and in the total "Handicap" group. Similar results were observed only in 1000 m for the "Conditional" group with lower Rho, except for PM10 and PM2.5. The total races of the conditional group showed lower Rho values and significant associations of the same trend for CO, NO2, NO and SO2. CONCLUSIONS: Horse races between 1000 and 1200 m of the "Handicap" type appear to be an interesting group to study the relationship between air pollutants and the performance of racehorses. In the future, our observations should be expanded to other distances and other types of races.

RESUMO

The impact of some atmospheric pollutants (PM10, PM2.5, O3, NO2, NO, SO2, CO), humidity and temperature were studied on the performance of thoroughbred racehorses. The study included 162 official handicap races held in 2012 in Santiago de Chile, at distances of 1000, 1100 and 1200 m, on a track in good condition, with a layout that included a bend, during the summer and winter months. The environmental variables were measured at the time of the race and were obtained from a monitoring station located 470 m from the equestrian center. The environmental variables showed an autocorrelation of variables, so they were reduced using principal component analysis. Subsequently, the principal components were correlated with running speed using Pearson's method. Totals of 60.17 and 23.29% of the total variability of the data was explained by principal components 1 and 2 (PC1 and PC2), respectively. PC1 was mainly determined by NO, NO2, and CO (loadings~0.90) and secondarily by PM10, PM2.5, and SO2 (loadings~0.6), with which the data showed inverse associations, while with temperature and O3 it showed direct associations (loadings~0.7). In addition, this component correlated negatively with running speed (r = -0.50), while PC2 was not associated with this variable. In conclusion, using the principal component analysis strategy, it was determined that running speed is affected by air pollutants.

RESUMO

El propósito de esta investigación fue determinar la eficacia de la pentoxifilina en el tratamiento de la hemorragia pulmonar inducida por el ejercicio (HPIE) en equinos Purasangres de carreras. Para tal fin, se seleccionaron en forma aleatoria 146 animales con edades comprendidas entre 3 y 8 años de edad, los cuales fueron sometidos a dos ejercicios intensos (14,6 ± 0,4 m/s) en distancia de 1000 metros, procediéndose luego a realizar una evaluación endoscópica del tracto respiratorio superior, entre 30 y 90 minutos después de cada ejercicio, con el fin de determinar la presencia de la HPIE y caracterizar la intensidad del sangramiento. Posteriormente, del conjunto de animales que presentaron HPIE en ambos ejercicios, se seleccionó al azar una muestra representativa constituida por 40 equinos, los cuales fueron asignados a dos grupos, 20 animales (grupo I) a los cuales se les administró pentoxifilina (8,5 mg/kg, q 12 h, PO) por 7 días y 20 ejemplares (grupo II) que no recibieron tratamiento. Seguidamente el día posterior a la finalización del tratamiento, a cada uno de los animales (grupo I y II), se les realizó una tercera evaluación endoscópica del tracto respiratorio superior de 30 a 90 minutos después de un ejercicio intenso en distancia de 1000 metros, para determinar la ocurrencia y severidad de la HPIE. El análisis de los datos demostró diferencia estadísticamente significativa (P < 0,05) entre la presencia e intensidad de la HPIE y la administración de la pentoxifilina, observándose que 8 (40%) de los animales tratados no presentaron HPIE, mientras que 20 (100%) de los equinos a los cuales no se les suministró la droga evidenciaron HPIE. Igualmente se determinó que la ocurrencia de HPIE moderada, profusa y visible, respectivamente, fue mayor en los animales no tratados. Por lo tanto, el tratamiento con pentoxifilina ayuda a prevenir o disminuir la HPIE.

The purpose of this investigation was to determine the efficacy of the pentoxifylline in the treatment of exercise-induced pulmonary hemorrhage (EIPH) in Thoroughbred racehorses. One hundred forty six (146) animals were randomly selected with ages between 3 and 8 years old, they were subjected to two intense exercises (14.6 ± 0.4 m/s) on distances of 1000 meters each, the horses were submitted to endoscopic evaluation of the respiratory tract, between 30 and 90 minutes after each exercise, the objective was to determine the presence of the EIPH and to characterize the intensity of the bleeding. Later, the group of animals which presented EIPH on both exercises was selected in random order as representative sample of bleeding racehorses. They were 40 equines divided in two groups, 20 animals (group I) received pentoxifylline (8.5 mg/kg, q 12 h, PO) for 7 days and 20 horses (group II) that did not receive treatment. Subsequently, the day after the end of the treatment, on each one of the horses (group I and II), a third endoscopic evaluation of the upper respiratory tract was performed, 30 to 90 minutes after an intense exercise on 1000 meters distance, in order to see the occurrence and severity of the EIPH. The analysis of the data demonstrated statistically significant difference (P < 0.05) between the presence and intensity of the EIPH and the administration of the pentoxifylline. Eight (40%) of the pentoxifilline-treated animals showed not EIPH, 20 (100%) not treated horses had evidence of EIPH. It was determined that the occurrence of moderate, profuse and visible EIPH respectively was larger in the not treated animals. Therefore, the treatment with pentoxifylline helps to prevent or to diminish the EIPH.