acupuncture on woman's backThey really were careful to only use 3 dogs.  This is a collaborative study between China and Austria as is typical of the Litscher group. This is a good example of why this works so well.  In China they are able to get around animal issues easier… Free article here.

Their results are pretty interesting in that, according to this study, the nervous system at the cervical level is key to the autonomic response of acupuncture not the peripheral autonomic nervous system.

Evid Based Complement Alternat Med. 2013;2013:419212. doi: 10.1155/2013/419212
Effects of acupuncture on heart rate variability in beagles; preliminary results.
Wang H, Litscher G, Shi X, Jiang YB, Wang L.
Department of Acupuncture, People’s Liberation Army General Hospital, Beijing 100853, China.
Evidence-based animal experimental research concerning the effects of acupuncture on autonomic function was performed by two research teams from China and Austria. This study describes measurements in beagles. Heart rate variability (HRV) recordings were performed under stable conditions in Beijing, China, and the data analysis and interpretation were completed in Graz, Austria. The electrocardiograms were recorded during bilateral body acupuncture (PC6, Neiguan). Power of the low frequency (LF), high frequency (HF), and the ratio (LF/HF) changed significantly during acupuncture stimulation in beagles after injection of atropine and ß -blocker. However, there was no significant change in HF power after needling the Neiguan acupoint when a cervical vagotomy has been performed. Our findings show that acupuncture can mediate the HRV even after pharmaceutical blocking of autonomic function. Acupuncture effects on HRV should rely not only on autonomic nervous system but on complete central nervous system.