Electroacupuncture

A set of “Baihui,” “Santai,” “Ergen,” and “Sanyangluo” points (here using the Pinyin Naming System instead of the Meridian Numbering System because animal’s meridians are not completely recorded) were selected, which were traditionally used in veterinary medicine to achieve effective analgesia in cattle (Peng et al., 1982) and goats (Liu et al., 2009). The anatomic location and use of these points have been described in detail in veterinary medicine (Klide and Kung, 1982). The “Baihui” point was identified on the dorsal midline between the spinous processes of the last lumbar and the first sacral vertebrae (but Baihui point in humans is located at the top of the skull). The “Santai” point was identified on the dorsal midline between the spinous processes of the fourth and fifth thoracic vertebrae. The “Ergen” points were identified bilaterally, with each at the pit ventrocaudal to the ear base between the ear base and the cranial border of the transverse process of the atlas on each side. The “Sanyangluo” points were also identified bilaterally, with each at approximately 5 cm ventral to the lateral tuberosity of the radius in the groove between the common digital extensor and the lateral digital extensor muscles of the forelimb. The “Baihui” and “Santai” points on the dorsal midline and the “Ergen” and “Sanyangluo” points on the right side of the body were used in this study. The acupoint sites were shaved and disinfected. The acupuncture needle (0.45 mm in diameter and 5 cm in length) was inserted perpendicularly into the “Baihui” point at a depth of approximately 3 cm. For the “Santai” point, the needle was inserted at a 45° angle at a depth of approximately 4 cm. These two needles shared a pair of wires from one output of the WQ-6F Electronic Acupunctoscope (Beijing Xin dong hua Electronic Instrument Co., Ltd., Beijing, China). One needle (0.45 mm in diameter and 7.5 cm in length) was inserted into the right “Ergen” point to reach the subcutaneous tissue of the right temporal fossa. Another needle was inserted at a 30° angle in a ventromedial direction into the right “Sanyangluo” point to reach the subcutaneous tissue of the medial side of the right forelimb. The two needles shared a pair of wires from another output of the same machine, and the parallel output option was selected. EA parameters were set according to the report by Qiu et al. (2015). The goats were stimulated with EA at 60 Hz; the intensity (3.2 V) remained constant during the entire EA procedure. The goats that were only dealt with needles left in the acupoints without electricity were used as the sham control. The goats in the blank control group were not treated with either needles or electricity. The goats in the blank and sham control groups were restrained as the EA-treated goats for consecutive 6 h, and then unlashed. The needles were withdrawn immediately.