Influência da fármaco-acupuntura nas respostas de estresse de equinos durante o transporte rodoviário

Abstract

Transport is a potential stressor for horses. Repeated, prolonged or exaggerated reactions to stress are associated with the onset of several diseases. Thus, it is essential to use strategies that can reduce the potential stressor of transport in horses. Acupuncture has shown beneficial effects in reducing stress responses in studies in animals and humans. The pharmacoacupuncture is a technique of the acupuncture that involves the injection of low doses of drugs to acupuncture points, aiming the therapeutic effect without the unwanted side effects of the total dose of the drug. Acepromazine (ACP) is a phenothiazine, commonly used to produce sedation in clinical or surgical procedures and animal transport. This experiment compared the effect of pharmaco-acupuncture (Group-VG 1- ACP 1 / 10; injection of 1/10 the usual dose of acepromazine at the acupoint VG 1), the aquapuncture (VG 1-SAL, saline injection at the acupoint VG 1), acepromazine (CTL-ACP; 0.1mg/Kg, IM in the neck) and the injection of saline in the neck (CTL-SAL) in the stress responses of healthy horses undergoing the stress of road transport (2,5 hours). The treatments were carried out immediately prior to loading and were evaluated the behavioral responses (activity score) and body temperature, respiratory rate, heart rate (measured using a heart monitor) and serum cortisol level (measured by radioimmunoassay). Sixteen male horses were used, 8 animals being transported per trip, where each animal was transported twice with one week interval between trips, totalizing 4 trips and 8 animals per group. The position on the truck and the treatments were fully randomized. The road transport increased heart rate (HR Med, HR Max and HR Min), respiratory rate, body temperature and serum cortisol levels. The pharmacoacupuncture (VG 1-ACP 1/10) was able to reduce the stress-induced increase of HR Med, without changing other parameters. The aquapuncture (VG 1-SAL) did not alter any of the parameters studied. Acepromazine (0.1 mg / kg, IM) produced significant sedation and blocked the increase in respiratory rate induced by stress, which may suggest respiratory depression. In addition, acepromazine did not prevent the stress-induced increase of the cortisol levels. These results suggest that the use of acepromazine in horses in transport should be considered with caution. Other types of stimulation of acupuncture points should be tested to verify the beneficial effect of this therapy to reduce stress in horses.