Dignity in Death: Our Role in Wildlife Euthanasia

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Dignity in Death Our Role in Wildlife Euthanasia

• Patrice N. Klein, MS VMD DACPV DACVPM
• Veterinary Consultant
• Second Chance Wildlife Center, Gaithersburg, MD

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A Wildlife Rehabilitators Code of
EthicsNWRA-IWRC Minimum Standards for Wildlife
Rehabilitation 2000

• A wildlife rehabilitator should strive to
  provide professional and humane care in all
  phases of wildlife rehabilitation, respecting
  wildness and maintaining the dignity of each
  animal in life and in death. Releasable animals
  should be maintained in a wild condition and
  released as soon as appropriate.
• Non-releasable animals that are inappropriate
  for education, foster-parenting, or captive
  breeding have a right to euthanasia.

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Responsibilities

• Welfare of the animals
• Needs of the patient
• Release to the wild
• Non-release options

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Life and Death Decisions

• The essential role of the wildlife rehabilitator
  is as an advocate for wildlife in their care
• We ensure that they are treated humanely
• We ensure their right to euthanasia if that is
  more humane than attempting treatment
• A captive life can be so diminished in quality
  that its maintenance would be an act of cruelty
• Euthanasia is a compassionate, moral alternative

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Impacts

• We lose our ability to help when
• Exhausted, overwhelmed trying to save every
  animal
• Money, Staffing, Time are limiting resources
• We should
• Direct our efforts to save animals with the best
  chance for return to the wild
• Provide other animals with a dignified, humane
  death
• We are the caretakers and advocates for wildlife
• We educate and influence the public on wildlife
  conservation and habitat preservation

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We Need to Understand.

• Why we should perform euthanasia
• When it is the best course of action
• How to do it humanely

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The Quality of Life for Wildlife

• Freedom
• Independence
• Ability to make choices
• Availability of shelter and refuge
• Potential to reproduce and evolve
• Restoration of liberty if potentially lost by
  injury, disease, orphaning, displacement

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Criteria for Release

• Age and health
• Physical capability
• Survival skills
• Food, hunting
• Shelter, nest building
• Waterproofing
• Behavior (tame, habituated, imprinted)
• Release location and habitat
• Season (climate, temperature, migration)

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What about Non-releasable Animals?

• Considerations for permanent placement
• Type and quality of the facility
• Temperament of the animal
• Rarity of species
• Essential needs of wild animals in captivity
• Psychological health
• Physical comfort
• Security
• Proper diet
• Companionship

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Wild Animals That Should Not Be Released

• Visual impairment in both eyes (blind)
• Impaired use in two or more legs
• Birds with partial/complete amputation of a leg
• Birds that cannot fly
• Turtles with critical shell loss/ dysfunction
• Tamed, habituated, imprinted
• Carriers of non-endemic diseases

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Criteria for Electing Euthanasia

• Will the animal be able to sustain a normal life
  in the wild with others of its own species?
• Does suitable habitat exist in which to release
  the animal once it has recovered?
• In captivity, will the animal have proper
  housing, nutrition, and stimulation to ensure its
  physical and psychological well-being?

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Practical Considerations

• Who will perform the euthanasia?
• What techniques will be used?
• How will the carcasses be disposed?

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Definitions

• Euthanasia
• the act of inducing a painless death.
• (Gk) eu good and thanatos death
• Implicit in the definition of euthanasia is the
  needed control over the animal and its experience
  during the process of euthanasia

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The Concepts of Pain

• Pain the sensation (perception) resulting from
  nerve impulses reaching the cerebral cortex
  (brain) via specific nociceptive neural pathways
  triggered by noxious stimuli.
• Nociceptive from noci to injure and ceptive
  to receive
• Noxious stimuli temperature, pressure,
  chemicals, trauma which may and do destroy
  tissues.
• To experience pain, the cerebral cortex and
  subcortical structures in the brain must be
  functional.

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The Concepts of Stress

• Stress is caused by the effect of physical,
  physiological, and psychological factors
  (stressors) that induce an alteration in
  homeostasis or the adaptive state.
• Response varies according to species, breed, age,
  health status.
• Response is an adaptive process to restore
  homeostasis
• Distress results when the response to stressors
  causes harmful effects to the well-being of the
  animal.

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General Criteria for Euthanasia Methods

• Rapid unconsciousness and rapid death
• Minimized pain, distress, and anxiety
• Minimized movements
• Rapid, reliable, irreversible cardiac and
  respiratory arrest
• Compatibility with species, age, health status
• Compatibility with requirement, purpose, and
  subsequent evaluation/use of tissues
• Predator/ scavenger safety (if carcass consumed)
• Personnel safety and emotional impact
• Drug availability/human abuse potential
• Maintenance of equipment

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Basic Mechanisms of Actions

• Hypoxia muscle paralytic agents are not
  acceptable as sole agents for euthanasia
• Succinylcholine Strychnine Nicotine
• Curare Gallimine K or Mg salts
• Depression of vital neurons (/- excitatory
  phase)
• Barbituates CO2 / CO
• Inhalant anesthetics Tricaine methanesulfonate
  (MS-222)
• Physical disruption/ destruction of brain
  activity
• Gunshot Penetrating captive bolt
• Cervical dislocation Decapitation

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Potassium chloride in Conjunction with Prior
General Anesthesia

• Potassium chloride (KCl) administered IV or IC
  AFTER animal is under surgical plane of
  anesthesia.
• Rapid cardiotoxic effect (1-2 mmol/kg BW)
• Safe for predators/scavengers that may consume
  carcasses but what about anesthetic residue?
• Inexpensive and not a controlled substance
• Muscle spasms may occur briefly after injection

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Barbituates

• Advantages
• Rapid unconsciousness without pain, distress
• Rapid and irreversible depression of CNS,
  cardiac, and respiratory functions
• Works well in many species

• Disadvantages
• DEA-Controlled substance
• Licensed veterinarians
• IV, IP routes
• IC only in unconscious animal
• Carcasses must be disposed properly, NO
  consumption

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Inhalant anesthetics(halothane, isoflurane,
sevoflurane)

• Advantages
• Rapid unconsciousness
• Direct depression of CNS
• Veterinary prescription
• Relatively inexpensive

• Disadvantages
• Species, age, health limits
• Resistance to effects in the young, the old, and
  with respiratory impairment
• May be reversible
• Proper ventilation required for personnel safety
• May need second method to ensure death

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Inhalant Gases(Carbon Dioxide/ CO2)

• Advantages
• Moderately rapid loss of consciousness
• Direct depression of CNS, resp. and cardiac
  functions
• Inexpensive
• Compressed gas cylinders
• No accumulation in tissues

• Disadvantages
• Species, age, health limits
• Aquatic animals, neonates, debilitated animals
  more resistant to ?CO2 levels
• Small birds/mammals (lt7 kg)
• Reptiles/amphibians breathe too slowly for CO2
• Irritant to respiratory mucosa (carbonic acid)

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?YES
NO?
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Inhalant Gases(Carbon Monoxide/ CO)

• Advantages
• Rapid unconsciousness and death at 4-6 CO concs.
• Direct depression of CNS, resp. and cardiac
  functions
• Binds irreversibly to RBC hemoglobin ? hypoxemia
• Compressed gas cylinders
• Commercial chambers ()

• Disadvantages
• Very hazardous- gas is odorless and tasteless
  0.4 lethal for humans
• OSHA regulations
• Small mammals use

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Tricaine methane sulfonate (MS-222)

• Advantages
• Used in aquatic tanks for amphibians and fish
• Moderately rapid loss of consciousness and death
  at proper exposure concentration
• gt250 mg/L solution, continue exposure gt10 minutes
  after movement cessation

• Disadvantages
• 21-day withdrawal time, not for use in food
  animal
• Anesthesia only at lower concentrations
  reversible
• Moderately expensive
• Proper storage conditions

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Gunshot to the Brain

• Advantages
• Rapid unconsciousness and death with proper use
• Direct destruction of brain tissue with proper
  use
• Must know anatomy!
• Field emergency use
• Carcasses may be consumed

• Disadvantages
• Personnel safety
• Firearm permits
• Government ordinances
• Maintenance of skill and proficiency required
• Animal restraint needed for accuracy
• RVS testing constraints

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Penetrating Captive Bolt

• Advantages
• Rapid unconsciousness and death with proper use
• Direct destruction of brain tissue with proper
  use
• Must know anatomy!
• Carcasses may be consumed

• Disadvantages
• Maintenance of skill and proficiency required
• May require firearm permits
• Animal restraint for accuracy
• Maintenance of equipment

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Cervical Dislocation

• Advantages
• Moderately rapid loss of consciousness and death
• Severs spinal cord and ascending pain pathways to
  brain
• Carcasses may be consumed
• No special equipment needed
• Must know anatomy!

• Disadvantages
• Mastery of technical skill and proficiency
  required
• Use limited to small birds and small rodents
  (lt200 gm)
• Prior sedation recommended
• Residual brain electrical activity (13-14 secs)
  ???
• Must know anatomy!

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Cervical DislocationAvian Skeletal Anatomy
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Decapitation

• Advantages
• Rapid unconsciousness and death
• Severs spinal cord and ascending pain pathways to
  brain
• Carcasses may be consumed

• Disadvantages
• Handling/ restraint may be distressful to animals
  
• Personnel safety/ injury
• Prior sedation recommended
• Residual brain electrical activity (13-14 secs)
  ???
• Maintenance of equipment

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Adjunctive Methods

• NOT AS SOLE METHODS FOR EUTHANASIA
• Must be used with another method to ensure humane
  death
• Stunning
• Blunt force trauma
• Non-penetrating captive bolt
• Electrical stunning
• Neuromuscular blocking agents
• Pithing
• Exsanguination

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Unacceptable Methods

• Neuromuscular blocking agents (alone)
• Drowning
• Freezing
• Thoracic compression
• Acetone
• dimethyl ketone
• Nighty-nite
• Air embolism

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O2
CO2
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Summary of Euthanasia Methods

• Birds
• Sodium Pentobarbital
• Isoflurane, sevoflurane
• CO2 (/- prior sedation)
• Anesthesia followed by cervical dislocation

• Reptiles
• Sodium pentobarbital
• Isoflurane, sevoflurane
• Anesthesia (inj.)followed by destruction of brain
  function (pithing, decapitation)
• Time to lethal effect of a chemical method may be
  prolonged and may require use of a secondary
  method to ensure death.

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Summary of Euthanasia Methods

• Rodents, Bats, and Small Mammals
• Sodium pentobarbital
• Prior sedation may be required for restraint
• Isoflurane, sevoflurane
• Anesthesia followed by cervical dislocation

• Hoofstock (deer)
• Sodium pentobarbital
• Prior chemical or physical immobilization
  required for restraint
• Gunshot to the brain
• Penetrating captive bolt

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Additional Information

• AVMA www.avma.org
• 2007 AVMA Guidelines on Euthanasia
• AAZV www.aazv.org
• Guidelines for Euthanasia of Nondomestic
  Animals, 2006
• Animal Welfare Institute, NAL/USDA
  www.nal.usda.gov
• UFAW www.ufaw.org.uk
• HSUS www.hsus.org
• AHA www.american-humane.org
• USFWS Regional Permit Offices www.usfws.gov
• OSHA www.osha.gov

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Questions?
Patrice.N.Klein_at_aphis.usda.gov patriceklein_at_hotmai
l.com (W) 301-734-0738
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