The return to consciousness of 24 electrically stunned lambs was assessed by measurement of physiological reflexes and electroencephalography (EEG) recordings.
The physical activity of the lambs after head-only electrical stunning included one tonic phase and two clonic phases.
The results suggest that during the tonic phase and the first clonic phase, the animal was unconscious, whereas during the second clonic phase the return of some conscious function began. Spontaneous breathing returned at about 29 s post-stun, whereas the corneal reflex returned at about 38 s. It is therefore suggested that the return of spontaneous breathing is the safest indicator that the animal is close to recovering consciousness.
Velarde, A. et. Al., UFAW, Volume 11, Number 3, November 2002 , pp. 333-341(9)
