Humane-Slaughter-Guidelines

ence of the animal and competence of the personnel
performing slaughter. Proper handling is vital to minimizing
pain and distress in animals and to ensuring the
safety of the person performing slaughter, any bystanders,
and other animals that are nearby.
Selection of the most appropriate method of humane
slaughter in any situation will depend on the species
and number of animals involved, available means
of animal restraint, skill of personnel, and other considerations.
Personnel who slaughter animals for food
must demonstrate proficiency in the use of the technique
in a closely supervised environment. Each facility
where slaughter is performed is responsible for appropriately
training its personnel. Experience in the humane
restraint of the species of animal is critical. Training
should include familiarity with the normal behavior
of the species, an appreciation of how behavior affects
handling and restraint, and an understanding of the
mechanism by which the selected technique induces
loss of consciousness and death.
Death must be verified before invasive dressing begins
(or before disposal of the animal for meat-quality
reasons). Personnel must be sufficiently trained to recognize
the cessation of vital signs of different animal
species.
The POHS gave serious consideration to the following
criteria in their assessment of the appropriateness
of slaughter methods: 1) ability to induce loss
of consciousness followed by death with a minimum
of pain or distress, 2) time required to induce loss of
consciousness and the behavior of the animal during
that time, especially for religious slaughter, 3) reliability
and irreversibility of the methods resulting in death
of the animal, 4) safety of personnel, 5) compatibility
with intended animal use and purpose (ie, meat consumption),
6) potential psychological or emotional impacts
on personnel, 7) ability to maintain equipment
in proper working order, and 8) legal and religious requirements.
These Guidelines do not address every contingency.
In circumstances that are not clearly covered by
these Guidelines, a veterinarian experienced with the
species in question should apply professional judgment
and knowledge of clinically acceptable techniques in
selecting a humane method of slaughter or euthanasia
(if required) to end an animal’s life in the best way possible.
The veterinarian should consider whether 1) the
procedure results in the best outcome for the animal,
2) their actions conform to acceptable standards of
veterinary practice and are consistent with applicable
federal, state, and local regulations, and 3) the choice
of slaughter or euthanasia technique is consistent with
her or his professional obligations and ethical commitment
to society.
I4 Stress and Distress, Unconsciousness, and Pain
These Guidelines acknowledge that a humane approach
to the slaughter of any animal is warranted,
justifiable, and expected by society. The overall goal
should be to minimize or eliminate anxiety, pain, and
distress prior to loss of consciousness. Therefore, both
the induction of unconsciousness and handling prior
to slaughter must be considered. Criteria for determining
the humaneness of a particular slaughter method
can be established only after the mechanisms of pain,
distress, and consciousness are understood. For a more
extensive review of these issues, the reader is directed
to the AVMA Guidelines for the Euthanasia of Animals:
2013 Edition.
Humane slaughter methods produce unconsciousness
through four basic mechanisms: 1) physical disruption
of brain activity (eg, blunt cranial trauma,
penetrating captive bolt, gunshot), 2) hypoxia (eg,
controlled low atmospheric pressure for poultry, N 2
, Ar,
exsanguination), 3) direct depression of neurons necessary
for life function (eg, CO 2
), or 4) epilepitiform
brain activity (eg, electric stunning). Because loss of
consciousness resulting from these mechanisms can
occur at different rates, the suitability of a particular
agent or method will depend on the species and whether
an animal experiences pain or distress prior to loss of
consciousness.
Distress during slaughter may be created by the
method itself or by the conditions under which the
method is applied and may manifest behaviorally (eg,
overt escape behaviors, approach-avoidance preferences
[aversion]) or physiologically (eg, changes in heart
rate, sympathetic nervous system activity, hypothalamic-pituitary
axis activity). Stress and the resulting responses
have been divided into three phases. 6 Eustress
results when harmless stimuli initiate adaptive responses
that are beneficial to the animal. Neutral stress results
when the animal’s response to stimuli causes neither
harmful nor beneficial effects to the animal. Distress
results when an animal’s response to stimuli interferes
with its well-being and comfort. 7 Although sympathetic
nervous system and hypothalamic-pituitary axis activation
are well accepted as stress response markers, these
systems are activated in response to both physical and
psychological stressors and are not necessarily associated
with higher-order CNS processing and conscious
experience by the animal. Furthermore, use of sympathetic
nervous system and hypothalamic-pituitary axis
activation to assess distress during application of CAS
methods is complicated by continued exposure during
the period between loss of consciousness and death. 1
Ideally, humane stunning and slaughter methods
result in rapid loss of consciousness and the associated
loss of brain function. The perception of pain is defined
as a conscious experience 8 and requires nerve impulses
from peripheral nociceptors to reach a functioning
conscious cerebral cortex and the associated subcortical
brain structures. The International Association for
the Study of Pain describes pain as “an unpleasant sensory
and emotional experience associated with actual
or potential tissue damage, or described in terms of
such damage. Activity induced in the nociceptor and
nociceptive pathways by a noxious stimulus is not pain,
which is always a psychological state, even though we
may well appreciate that pain most often has a proximate
physical cause.” 9 Pain is therefore subjective in
the sense that individuals can differ in their perceptions
of pain intensity as well as in their physical and behavioral
responses to it.
Distress during administration of CO, CO 2
, and
the inert gases N 2
and Ar has been evaluated by use
AVMA Guidelines for the Humane Slaughter of Animals: 2016 Edition 7