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Introduction: Horse racing is a major sport practiced worldwide. The environment to which horses are exposed during race meetings can influence their behavior. However, to the best of our knowledge, a method for assessing a horse's response to its surroundings during the pre- and post-race periods has not yet been reported. This study aimed to create a standard list of descriptors for use in a qualitative behavioral assessment (QBA) focused on assessing the emotional expressivity of horses before and after racing events. Materials and methods: Seventy pre- or post-race 30-second videos of horses were randomly selected from our database of 700 videos. A panel of 8 experienced equine sports medicine specialist veterinarians watched a 60 min presentation on QBA. The panel then watched all videos randomly, simultaneously, individually, continuously, and without any verbal interaction, describing the descriptors related to the emotional expressivity of the horse after each video using a method known as free-choice profiling (FCP). Results: The initial selection of descriptors was based on those indicated by more than one evaluator in the same video, or descriptors with more than 20 occurrences. The second selection was performed based on the content validity index (CVR) to select the descriptors retained in the previous step. Another panel of six veterinarians scored each of the descriptors retained for content validity on a visual scale. Interobserver reliability was estimated using the intraclass correlation coefficient (ICC) and its respective 95% confidence intervals (CI). A natural language processing (NLP) algorithm was used to analyze the behavior (positive or negative polarity) of the descriptors based on the lexicoPT package of R software. Discussion/Conclusion: NLP analysis considered the descriptors "agitated," "troubled," "restless" and "irritated" to have a negative polarity, while "focused," "relaxed" and "peaceful" had a positive polarity. In the principal component analysis (PCA), descriptors in a negative state were associated with each other and inversely associated with descriptors in a positive state. We conclude with a fixed list of descriptors to be used in a QBA to assess emotional and welfare expressivity in racehorses' pre- and post-race environments.

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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.

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Racehorses are constantly exposed to stress. Aiming to verify the state of blood components and cortisol alterations during their routine and after races, phagocytosis and oxidative neutrophil burst assays, serum cortisol determination, erythrocytes apoptosis evaluation, lymphoproliferation assays, and blood count tests were performed in thirty Thoroughbred racehorses, which were divided in two groups. The samples were taken right after races (moment 0 d), during rest periods (-11 d, +1 d, +3 d), and after training (-8, +2, +5). In both groups, the phagocytosis showed a decrease in percentage and intensity immediately after the race when comparing samples collected during rest or training periods. In the mean values of oxidative burst on samples collected immediately after the race, group I animals demonstrated a decrease (524.2 ± 248.9) when compared with those samples collected in other moments. No significant differences were found between the results of different moments regarding the apoptotic cells and lymphoproliferation assays. The mean values of serum cortisol levels were increased immediately after racing. There was an increase in the percentage of neutrophils found immediately after the race. It was possible to conclude that, although a transient reduction was found in the number of neutrophils, the horses' adaptive function was not affected.

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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.

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The high prevalence of exercise-induced pulmonary hemorrhage (EIPH) in athletic horses constitutes to be a challenge to the racing industry and a source of major concern to animal welfare. Both experimental and clinical evidence indicate that the use of autologous platelet-rich plasma (PRP) is a promising effector of repair in a variety of pulmonary conditions. The present study evaluated the effect of intrabronchial instillation of PRP on EIPH endoscopic scores from 37 Thoroughbred racehorses. Inclusion criteria were for animals to be EIPH-positive in, at least, two consecutive post-exercise endoscopic exams and to receive 250mg of furosemide IV four hours before racing. Animals were randomly assigned into 3 groups: placebo, control, and PRP instillation. All 37 Thoroughbred racehorses included had EIPH endoscopic scores pre- and post- treatment compared by statistical analysis. The bleeding score from the group receiving PRP was significantly lower than in the control and placebo groups. No adverse effects were observed in any animal during or after the experiment. It was possible to conclude that the intrabronchial instillation of autologous PRP was effective in reducing EIPH scores in racehorses receiving furosemide and that this bioproduct can be considered as a promising coadjuvant in controlling EIPH in athletic horses.(AU)

A alta prevalência de hemorragia pulmonar induzida por exercício (HPIE) em cavalos atletas é um desafio de longa data para a indústria de corridas, além de figurar como grande preocupação sobre o bem-estar animal. As evidências experimentais e clínicas indicam que o uso do plasma rico em plaquetas (PRP) de fonte autógena é promissor na terapêutica de diversas lesões pulmonares. O presente estudo objetivou avaliar as mudanças após corrida no escore endoscópico de HPIE de 37 cavalos Puro-Sangue Inglês que receberam instilação intrabronquial de PRP autólogo. Os animais selecionados eram HPIE-positivos em, ao menos, dois exames endoscópicos consecutivos e recebiam 250mg de furosemida IV administrado quatro horas antes de cada corrida. Na comparação dos escores endoscópicos pré e pós-tratamento, verificou-se que o escore de HPIE do grupo tratado com PRP foi significantemente menor que o dos grupos controle e placebo. Nenhum efeito adverso foi observado nos animais durante ou após o experimento. Concluiu-se que a instilação intrabronquial de PRP autólogo foi efetiva na redução do escore de HPIE de cavalos de corrida usuários de furosemida e que este bioproduto pode ser considerado uma alternativa promissora no controle de HPIE em cavalos atletas.(AU)

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Reproductive phenology is an important trait subjected to natural selection. Current horses in America belong to the Palearctic original populations after being introduced by European colonizers. Photoperiod variation is the main environmental factor for the adjustment of reproductive timing in horses, but is absent in equatorial areas. Here we hypothesize that seasonality of green-grass availability may influence breeding phenology in equatorial regions. We used data of 929 services to mares from 2006 to 2011 in a thoroughbred equine exploitation in Ecuador that experienced strong grass seasonality. Actual births could not be used to infer natural phenology because they were influenced by management decisions. Instead, we used variations in the probability of pregnancy after a service as a measure of the natural tendency of mares to show breeding phenology. We found that although managers tended to schedule pregnancies in two periods within the year, mares were more prone to become pregnant after the increase in grass greenness that takes place at the beginning of the year (February). Our finding has potential applications to improve the success of services and the welfare of animals, by providing green-grass stimuli in the appropriate season.

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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.