Chemical Immobilization

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Chemical Immobilization
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What is it?

• Anesthesia of wild, free-ranging, feral animals,
  or those unaccustomed to human contact
• Can be given with or without physical restraint
  of the animal

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Objectives

• Handle a wild animal in a manner that
• Inflicts least amount of stress and pain to
  animal
• Has least risk of injury to both animal and
  handler
• Requires
• Patience
• Humaneness
• Animal care
• Personal safety

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When should it be used?

• Only as a last resort
• When all other means of restraint are
  insufficient
• Does the need to capture or handle this animal
  justify risking this animals life?
• Commonly used for a variety of species
• Carnivores
• Ungulates
• Small mammals

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Pros

• Research
• Attaching radio collars, ear tags, etc.
• Taking blood or other samples
• Moving an animal from one location to another
• Less trauma during handling
• Risk of injury and stress decreased

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Cons

• Cost
• Drugs
• 15-30 (per deer)
• Equipment
• Darts - 4 per dart
• Rifle - 500-700
• Transmitter - 200
• Receiver - 900

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Cons

• Cant determine physiological health of animal
  prior to administering drugs
• Risks to animal
• Physical injury
• Medical complications
• Respiratory arrest
• Cardiac arrest
• Shock
• Bloat
• Hyper-hypothermia

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Cons

• Risks cont.
• Fleeing animals have a higher chance of building
  up heat, and reacting poorly to the drug
• Ungulates and small mammals in recovery are more
  susceptible to predation
• Can cause social stress
• Change dominance hierarchies
• Neonates may be rejected

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Cons

• Risks to humans
• Risk from animals before they are knocked-out
• Risk from accidental exposure to the lethal drugs

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Drug Administration

• 4 basic types
• Hand injection with syringe
• Pole syringe jabstick
• Blow gun
• Dart gun

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Ungulates

• Since ungulates are difficult to approach,
  immobilization is used when
• They are confined to a corral or trap
• They are moderately habituated to people
• They can be stalked (hunted)
• Easiest method in some areas is to dart from a
  helicopter

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Carnivores

• Trapping is usually recommended before
  immobilization of large carnivores
• Can be immobilized with
• Dart gun
• Blowpipes
• Syringe poles (jabstick)

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Small Mammals

• Usually trapped then immobilized
• Raccoons usually immobilized with jab-stick, as
  they can carry rabies
• Other small mammals immobilized with a hand-held
  syringe or a jabstick

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Darting

• When would we need to dart an animal?
• How successful is this method?
• Fast enough for accuracy
• Slow enough as to minimize tissue damage

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Darting Considerations

• Will the dart function properly?
• Discharge mechanism
• Will the dart hit the targeted injection site?
• Where on the animal should you aim?

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Darting Considerations

• Will the dart deliver complete drug injection?
• Will the dart strike with excessive impact and
  cause injury?
• Will the wound become infected?

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Using a Dart Gun

• 3 types of dart guns
• Powder charged
• CO2
• Air
• Must practice at known distances
• Arcing trajectory
• Very poor ballistics
• Weight of dart
• Drugs
• Transmitter

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Using a Dart Gun

• Powder charged rifle
• Modified 22 caliber rifle
• 50 caliber barrel sits on top of conventional
  barrel
• Blank 22 charges - provide air pressure that is
  transferred into top barrel projecting dart
  towards target

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Using a Dart Gun

• Different types of darts
• 1 3cc
• Radio-tracking darts
• Helpful for free-ranging wildlife

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After the Shot

• Approach slowly, quietly
• Animal may need re-dose if not fully anesthetized
• Assess depth of anesthesia
• Blink reflex, ear reflex, heart and respiration
  rate

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After the Shot

• Proper positioning
• Sternal position for ungulates
• Protect eyes
• Apply lubricant
• Blindfold
• Monitor vital signs

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After the Shot

• Dart Removal
• Must be surgically removed (darts are barbed)
• Fill wound with antibiotic cream
• Observe animal until complete recovery
• If animal does not recover properly, then
  euthanasia may be the only option

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Drugs

• Controlled substances
• Must be obtained from licensed veterinarian
• DEA prescription
• Two Broad Categories
• Neuromuscular Blocking Agents
• Central Nervous System Agents

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Neuromuscular Blocking Agents

• Immobilize through paralysis
• Extremely low safety margin
• Mortality common with paralysis of respiratory
  muscles
• These have been banned as use for immobilizing
  animals
• High mortality rate, low safety margins

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Central Nervous System Drugs

• Act directly on brain/spinal cord
• Alter perception of environment
• Alleviate fear and anxiety
• Depress motor activity
• Three major types
• Opioids
• Cyclohexamines
• Neuroleptics

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Opioids

• Morphine-like
• Highly potent
• Effective in small volumes
• Wide margin of safety
• Can be immediately reversed
• Cause loss of consciousness, alleviates
  perception of pain
• Commonly used for free-ranging wildlife and zoo
  species

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Opioids

• Common opioids used in animal immobilization
• Carfentanil, Etorphine, Sufentanil, Fentanyl,
  Butorphanol
• Take care in handling minute doses are
  extremely toxic to humans
• Can be absorbed through mucous membrane

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Cyclohexamines

• Produce altered consciousness
• Dissociate mental state from environmental
  stimulation
• Retain many vital reflexes
• Cannot walk but can move tongue, blink,
  swallowing motion
• Peripheral analgesia (lack of pain perception)
• Sufficient to suture skin wounds

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Cyclohexamines

• Common Cyclohexamines
• Ketamine (Special K)
• Tiletamine -gt Telazol
• Phencyclidine (PCP)
• Cyclohexamines are dangerous when used alone and
  are NOT reversible
• Must be used in conjunction with other drugs
  (Neuroleptics)

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Neuroleptics

• Produce calmness and relaxation
• Referred to as tranquilizers
• Does not cause loss of consciousness or alleviate
  pain perception
• Will cause death before they cause loss of
  consciousness
• Neuroleptics are used in conjunction with other
  drugs (Cyclohexamines and Opioids)

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Neuroleptics

• Commonly used neuroleptics
• Diazapam (Valium)
• Very wide margin of safety
• Calming effect and muscle relaxation
• Xylazine (Rompun, Cervizine, Anased)
• Fairly wide margin of safety
• Drug of choice for carnivores and ungulates
• Immediately, completely reversible -gtTolazine

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Drug Mixtures

• Three Tiers
• Tier 1 ketamine neuroleptic (xylazine)
• Weakest knockdown power, short duration
• Tier 2 Telazol or Telazol neuroleptic
• Moderate knockdown power, long duration
• Tier 3 Opioid neuroleptic
• Highest knockdown power, duration determinant
  on reversal

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Drug Dosages

• How much drugs do we deliver to an animal?
• Based on 3 key pieces of information
• How much does the animal weigh (kg)?
• What is the recommended drug dosage for the
  species we are working with?
• What is the concentration of the medication we
  are using?

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White-tailed deer

• Separated into 3 categories, all with different
  drug recommendations
• Tame
• Mildly excited
• Wild, free-ranging
• Typically a xylazine/Telazol mixture
• 1 cc per 100 lbs.
• Reversal Drug tolazoline (Tolazine)
• Administered to bring animal back

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Summary

• Chemical immobilization can be beneficial, but
  there are many risks involved
• Darting, although a popular method, requires
  practice and patience
• Success rates are variable usually something
  goes wrong
• Prior to the shot you must know
• Approx. weight of animal you are shooting
• Almost exact distance to target, within 1-3 yards

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Summary

• Drugs
• Many various types used in wildlife
  immobilization
• Xylazine (Rompun)
• Tiletamine zolazepam (Telazol)
• Ketamine
• Carfentanil

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Summary

• Drugs
• Before administering you must know its
• Capabilities
• Side-effects
• Reversal Agents (if any)
• Effective Concentrations
• Species specific recommendations