Euthanasia

Question 1

Euthanasia Classfication

Answer 1

-acceptable
-acceptable with conditions
-unacceptable

Question 2

Criteria

Answer 2

12 criteria

Induce loss of consciousness and death with a minimum of pain and distress
-timely
-irreversible
-safety of personnel and predators (clean up)
-proper eIquipment
-compatible- exam, animal use, species, age and health status
-environmental impacts
-drug availability

Question 3

Ideal euthanasia

Answer 3

1. depression of neurons needed for life function= loss of consciousness
   *can include anesthesia
2. Hypoxia (cardiac and respiratory arrest)
3. Physical disruption of brain activity and destruction of neurons needed for life (loss of brain function)

Question 4

Euthanasia options

Answer 4

1. Chemical
   -inhalant
   -non inhalant (injectable/oral)
2. Physical

Question 5

Chemical inhalant agents

Answer 5

-isoflurane (irritating), Halothane, sevoflurane (non-noxious)

-NO increase to speed of onset

-Chamber method (small animals under 7kg)
*container large enough to prevent hypoxia

Question 6

Issues for chemical inhalant agents

Answer 6

-human exposure
-need confirmation of death
-cannot be used for reptiles, amphibians, diving birds and diving mammals because they can hold their breath

Question 7

Carbon monoxide/dioxide inhalant uses

Answer 7

-used for dogs/cats in some humane societies and for rodents and birds
-species dependent aversion

Question 8

CO

Answer 8

ACCEPTABLE, but
-signs of agitation, convulsions, muscle spasms, vocalization common (dogs/cats)

-source is important

-blocks O2 uptake by RBCs

Question 9

CO2 inhalant

Answer 9

Controversial but acceptable with conditions
-pain carbonic acid (resp/ocular membranes)
-breathlessness (resp acidosis)= panic
-this stimulates amygdala= fear response

*used in rats, mice, birds

Question 10

CO2 euthanasia demands for different species

Answer 10

Dogs: 30-40%
Cats: 60%
Birds: less than 25% (less than a min)

Question 11

Noninhalant methods

Answer 11

-barbiturates, Pentobarbital

-rapid and smooth
-can result in excitement and agonal gasp; add propofol or other sedation ahead of time

-give IV!

-must confirm death and be aware of risk for scavenging

Question 12

Barbiturates- birds and reptiles?

Answer 12

-most birds anesthetized first because otherwise they have massive excitement phase (wing flapping and vocalizations)

-reptiles (turtles, tortoises)
*give IC
**2-3 days before releasing to owner because they have 3 chambered heart and can slow it down
*loss of eye pressure is a good indicator

Question 13

T-61

Answer 13

-local anesthetic (tetra hydrochloride) and general anesthetic (embutramide)

-neuromuscular blocking agent
-not controlled drug
-AVMA acceptable but CCAC not recommended

Question 14

Concerns for T-61

Answer 14

-improper IV admin

-pain with admin

-mammals= dysphoria if given too quickly; resp paralysis/suffocation before loss of consciousness

-Birds= anesthesia immediate + EEG loss less than 6secs

Question 15

Horse euthanasia

Answer 15

Pentobarbital most common
-IV
-thick solution so given slowly
-sedation or anesthesia recommended
-risk of scavengers
-takes under 1 min; EEG 20sec

Question 16

Intrathecal lidocaine in horses

Answer 16

-given after anesthesia (Sedation needed)
-longer to resp, cerebral, brainstem and cardiovascular arrest compared to IV barbiturates
**blocks Na channels

-audible heart beat 5 mins; EEG 2mins

-little risk to scavengers

Question 17

Tricaine methane sulfonate (MS-222)

Answer 17

-suitable for fish and most amphibians

-need to give sodium bicarb to buffer

-not controlled drug

-anesthetic- increase concentration and prolong exposure

-some given IC

-need secondary method required to ensure death (sever spinal cord, puncture heart)

Question 18

Unacceptable agents

Answer 18

-Strychnine
-nicotine
-caffeine
-cleaning agents
-solvents
-pesticides
-disinfectants
-other toxins

Question 19

Physical methods

Answer 19

-captive bolt
-gunshot
-cervical dislocation
-decapitation
-electrocution
-kill traps
-thoracic compression
-exsanguination
-pithing

Question 20

Penetrating captive bolt

Answer 20

-ruminants, horse, swine, lab rabbits, dogs, birds

-concussion and trauman to cerebral hemisphere and brainstem

-need proper restraint to ensure proper placement

Question 21

Cervical dislocation

Answer 21

-used in rodents and birds

Question 22

Decapatation

Answer 22

-rodents for tissue collection
-wildlife

Question 23

Koechner euthanazing device

Answer 23

-Squeezes across neck- results in cervical vertebrae fractures

*longer to death than cervical dislocation

Question 24

Euthanasia by blow to head

Answer 24

-acceptable for neonatal animals with thin craniums (small birds, young piglets, neonates)

-single sharp blow delivered to central skull bones with sufficient force can produce immediate depression of the central nervous system and destruction of brain tissue

Question 25

Gunshot

Answer 25

-should only be performed by highly skilled personnel trained in the use of firearms

-legal requirements- only allows in areas with legal firearms

-aiming for brainstem (not between the eyes; aim for just below the ear)

Question 26

Emergency situations

Answer 26

Options that should only be considered if the animal is unconciousness:
-Exsanguination
-cardiac puncture

BUT think about timing/shortening time to death by any means