L13: euthanasia

what is euthanasia?

the act of inducing a humane death in an animal, minimizing pain and distress

what are the criteria for evaluating euthanasia methods?

1. humane end

2. reliability and speed

3. safety and impact

4. compatibility

what do we look at when evaluating a humane end?

Ability to induce loss of consciousness and death with a minimum of pain and distress

what do we look at when evaluating reliability and speed of euthansia?

time required to induce loss of consciousness and the overall reliability and irreversibility of the method

what do we look at when evaluating safety and impact of euthanasia?

• safety of personnel

• emotional effect on observers

• environmental impacts of disposal

what do we look at when evaulating compatibility of euthansia?

• Suitability for the species, age, and health status

• any subsequent use of tissues.

what does it mean for euthanasia method to be classified as acceptable?

Methods that consistently produce a humane death when used as the sole means of euthanasia

what does it mean for euthanasia method to be classified as acceptable with conditions?

Methods that require certain conditions to be met to consistently produce a humane death

what does it mean for euthanasia method to be classified as unacceptable?

• deemed inhumane under any conditions

• pose a substantial risk to the human operator applying the technique

what does it mean for euthanasia method to be classified as an adjunctive method?

should not be used as a sole method but can be used in conjunction with others to bring about euthanasia

what are the 3 basic mechanism of euthansia?

1. direct depression of vital neurons

2. hypoxia

3. physical disruption of brain activity

unconsciousness

• Loss of individual awareness,

• the brain´s ability to integrate information is blocked or disrupted

once consciousness is lost, what things may happen during stage 2 of anesthesia?

1. seizures

2. vocalization

3. reflex struggling

4. breath holding

5. tachypnea

what is the only single definitive sign in confirming death after euthanasia?

presence of rigor mortis

what are methods of euthanasia?

1. inhaled agents

2. non-inhaled agents

3. physical methods

what are some inhaled agents used for euthanasia?

1. carbon dioxide

2. isoflurane

what are some non-inhaled agents used for euthanasia?

1. barbituates

2. MS 222 for fish

what are some physical methods used for euthanasia?

1. gunshot

2. penetrating captive bolt

answer the MCQ

acceptable

answer the MCQ

adjunctive

answer the MCQ

unacceptable

how much must the animal weigh for inhaled agent to be acceptable?

smaller than 7 kg

what animals is inhalant anesthetics unacceptable for?

1. food producing animals

2. reptiles

3. amphibians

4. diving mammals/birds

5. neonatal animals

what is the order of preference of inhalant anesthetics for euthanasia?

1. isoflurane

2. halothane

3. sevoflurane

4. enflurane

5. methoxyflurane

6. desflurane

what are the advantages of using carbon monoxide for euthanasia?

• Painless nor discomfort in some species

• Rapid death at low concentrations

what are the disadvantages of using carbon monoxide for euthanasia?

• Aversive for lab rodents

• Potential to exposure to personnel

what are the recommendations for using carbon monoxide for euthansia?

acceptable with conditions

what is the preferred method of anesthesia especially in companion animals?

barbituates

what are the advantages of using barbiturates?

• Rapid onset of action when given IV

• Induces euthanasia smoothly with minimal animal discomfort

• Relatively inexpensive compared to other injectable agents

what are the disadvantages of using barbiturates for euthanasia?

• Intravenous injection requires trained personnel and animal restraint

• Strict DEA regulations require accounting and supervision

• Drug persists in the carcass, posing a significant secondary poisoning risk to scavengers

what are the advantages of using pentobarbital for euthanasia?

• Quick onset of action

• IV preferred for companion animals

• IP, intracelomic, intra-organ, IC: accepted with conditions

what is the recommendation for using potassium chloride as euthanasia method?

it is an adjunctive method

how does potassium chloride work as euthanasia agent?

potassium is cardiotoxic leading to cardiac arrest

what are the advantages of using potassium chloride in euthanasia?

• Rapid onset of action

• Not controlled substance

• Less residue issues

• No artefacts (necropsy)

what are the disadvantages of using potassium chloride in euthanasia?

• Possible spasms

• Painful injection

• No loss of consciousness

what are the advantages of using physical methods for euthansia?

• Inexpensive, humane, painless, no drug residues

• Less fear and anxiety

what are the disadvantages of using physical methods for euthansia?

can be upsetting for operator

what is pithing?

A rod is inserted through the skull hole, destroying brain tissue and spinal cord to prevent revival

what animals are physical methods for euthanasia acceptable with conditions?

1. horses

2. ruminants

3. swine

4. rabbits

5. poultry

for small animals, what is the acceptable method of euthansia?

IV injection of barbituate

for small animals, what are the acceptable with condition methods in euthansia?

1. IP injection (IV unacessible)

2. inhaled anesthetic (less than 7kg)

3. intra-organ injection (unconscious or anesthetized animals)

4. gunshot or PCB (remote areas or emergency)

PCB

penetrating captive bolt

what is the acceptable method of euthanasia for cattle?

IV barbituate overdose

what is the acceptable with conditions method of euthanasia for cattle?

1. gunshot

2. PCB

what is the acceptable method of euthanasia for swine?

gunshot or PCB to center of forehead

what is the acceptable method of euthanasia for horses?

gunshot or PCB at intersection from outer ear to center of base of opposite ear

what is the acceptable method of euthanasia for fish and aquatic invertebrates?

immersion anesthetics

what is the acceptable with conditions method of euthanasia for fish and aquatic invertebrates?

rapid chilling

what are unacceptable methods of euthanasia in a shelter?

1. gunshot

2. inhalation of carbon monoxide

3. intra-organ injections (unless unconscious)