Effect of Training Thoroughbred Foals on the Angle of Their Electrical Cardiac Axis and Magnitude of the Ventricular Vector

Abstract

Hanak J.: Effect of Training Thoroughbred Foals on the Angle of Their Electrical Cardiac Axis and Magnitude of the Ventricular Vector. Acta vet. Bmo, 51, 1982: 69-73. Effect of training upon the angle of the electrical cardiac axis and magnitude of the ventricular vector was investigated in 40 foals from the age of 13 -15 months until their transfer to a training centre at 17 - 20 months of age. A second group of 40 un­ trained foals served as control. Our study failed to show a significant effect of training on the angle ofthe electrical cardiac axis. Training did, however, affect the magnitude of the ventricular vector due to considerable bilateral ventricular hypertrophy. Foals, age, heart ventricle, hypertrophy. Better performance of race horses is a goal of breeders in countries with developed husbandry of thoroughbred horses. Great attention is also paid to rearing thoroughbred foals. Its part is a re­ gular, systematic and controlled physical activity of foals, often termed pre-training. Many schemes have been elaborated for training of foals. However, only few studies take into consideration also the clinical and physiological aspects. In an experiment of Ocsag (1971), foals were trained from the age of 13 -14 months on a racing course with 16 - 24 hurdles up to 80 em high. During the training period, the hemoglobin content and hematocrit value increased in experimental animals. The later performance of these horses was better as compared to an untrained group. Another method of pre-training was elaborated by Karlson et al. (1973) designed for trotters and based on clinico-physiological grounds. His experimental group, too, showed a better performance than the untrained control group. Elucidation of changes in the body of a foal during an early started training will undoubtedly contribute to the knowledge of the physiological basis of pre-training. Such knowledge would then serve better organization of training aimed at improved performance of race horses. The objective of the present study was to pay attention to the cardiovascular apparatus - a limi­ ting factor of performance in the horse. In context with the previous work (Hanak 1981) the dif­ ferences in vectorcardiogram of regularly trained vs. untrained foals are analysed.