Table 21.

ABMs for assessment of ‘State of consciousness’ after Head‐only electrical stunning.

ABMs	Description
Tonic/clonic seizures	Effective head‐only electrical stunning leads to the onset of tonic–clonic seizures soon after immediate collapse of the animal. The tonic seizure, which may be recognised from the tetanus, lasts for several seconds and is followed by clonic seizures lasting for seconds and leading to loss of muscle tone (EFSA AHAW Panel, 2013)
Breathing	Effective electrical stunning will result in immediate onset of apnoea (absence of breathing). Ineffectively stunned animals and those recovering consciousness will start to breath in a pattern commonly referred to as rhythmic breathing, which may begin as regular gagging and involves respiratory cycle of inspiration and expiration Rhythmic breathing can be recognised from the regular flank and/or mouth and nostrils movement. Recovery of breathing, if not visible through these movements, can be checked by holding a small mirror in front of the nostrils or mouth to look for the appearance of condensation due to expiration of moist air (EFSA AHAW Panel, 2013)
Palpebral and/or corneal reflex	The palpebral reflex is elicited by touching or tapping a finger on the inner/outer eye canthus or eyelashes. Correctly stunned animals will not show a palpebral reflex. Ineffectively stunned animals and those recovering consciousness will blink in response to the stimulus The corneal reflex is elicited by touching or tapping the cornea. Ineffectively stunned animals and those recovering consciousness will blink in response to the stimulus. Unconscious animals may also intermittently show a positive corneal reflex (EFSA AHAW Panel, 2013)
Spontaneous blinking	Conscious animals may show spontaneous blinking, and therefore, this sign can be used to recognise ineffective stunning or recovery of consciousness after electrical stunning. However, not all the conscious animals may show spontaneous blinking (EFSA AHAW Panel, 2013)
Posture	Effective head‐only electrical stunning will result in immediate collapse or loss of posture in animals that are not restrained or prevented from doing so. Ineffectively stunned animals, on the other hand, will fail to collapse or will attempt to regain posture after collapse (EFSA AHAW Panel, 2013)
Vocalisations	Conscious animals may vocalise, and therefore purposeful vocalisation can be used to recognise ineffective stunning or recovery of consciousness after electrical stunning. However, not all conscious animals may vocalise (EFSA AHAW Panel, 2013)
Muscle tone	Head‐only electrically stunned animals will show general loss of muscle tone after the termination of tonic–clonic seizures coinciding with the recovery of breathing and the corneal reflex if not previously stuck. Loss of muscle tone can be recognised from the completely relaxed legs, floppy ears and tail and relaxed jaws with protruding tongue. Ineffectively stunned animals and those recovering consciousness will show a righting reflex and attempts to raise the head (EFSA AHAW Panel, 2013)