Physical Methods

Question 1

What physical methods of euthanasia are not recommended as a sole means of euthanasia, but may be considered adjuncts?

Answer 1

Exsanguination, stunning, and pithing.

Question 2

Standard captive bolts may be inadequate for what species?

Answer 2

Water buffalo

Question 3

What is the method of action of penetrating captive bolt?

Answer 3

Concussion and trauma to the cerebral hemisphere and brainstem.

Question 4

What are the signs of effective captive bolt placement?

Answer 4

Immediate collapse and several-second period of tetanic spasm, followed by slow hind limb movement of increasing frequency. Corneal reflex absent, eyes open into a wide blank stare and not rotated.

Question 5

Describe air injection PCB.

Answer 5

Air under high pressure is injected through the bolt into the brain to increase the extent of tissue destruction.

Question 6

What caliber are powder-activated PCBs available in?

Answer 6

9mm, .22 caliber, and .25 caliber

Question 7

Why might repeated firings of a captive bolt gun for extended periods reduce effectiveness?

Answer 7

Overheating

Question 8

Why can air injection captive bolts be used on ruminants that will be used for food?

Answer 8

Concerns about contamination of meat with neurologic tissue

Question 9

NPCBs do not penetrate the brain of which animals?

Answer 9

Adult cattle, slaughter-weight pigs, sows, and adult sheep.

Question 10

Generally, how are NPCBs used?

Answer 10

Only stun animals, not used as a sole method of euthanasia.

Question 11

NPCBs are not effective for stunning what animals?

Answer 11

Bulls, adult swine, or cattle with long hair.

Question 12

Purpose-built or powder-activated pneumatic NPCB guns have been developed for what animals?

Answer 12

Suckling pigs up to 9kg (20 lb), neonatal ruminants, and turkeys

Question 13

In what situation can manually applied blunt force trauma to the head be a humane method of euthanasia?

Answer 13

In neonatal animals with thin craniums if a single sharp blow delivered to the central skull bones with sufficient force can produce immediate depression of the CNS and destruction of brain tissue.

Question 14

In which species has MABFT been used? In what species is it unacceptable, and why?

Answer 14

Small lab animals with thin craniums and young piglets.
Unacceptable in neonatal calves due to their anatomic features.

Question 15

Why does the AVMA encourage those using MABFT to search for alternatives?

Answer 15

Personnel become fatigued, which can lead to inconsistency in application and create humane concerns.

Question 16

Where should euthanasia via gunshot occur?

Answer 16

Outdoors in areas where public access is restricted.

Question 17

What is the goal of firearm selection regarding bullet penetration?

Answer 17

Penetration of brain tissue without emergence from the contralateral side of the head.

Question 18

Describe muzzle energy.

Answer 18

Muzzle energy = The energy of the bullet as it leaves the end of the barrel when the firearm is discharged. Used as an indicator of a bullet’s destructive potential. Heavier the bullet and the greater its velocity, the higher its muzzle energy and capacity for destruction of objects in its path.
Muzzle Energy (E) = Mass (M) x Velocity (V)^2 Divided by 2

Question 19

What is a concern with lighter-weight, higher-velocity bullets?

Answer 19

Have a high muzzle energy, but decreased penetration, which can be an issue when penetrating thick bones.

Question 20

For euthanasia, the combination of firearm and ammunition must achieve a muzzle energy of at least what?

Answer 20

300 feet-lb (407 J) for animals weighing up to 400lb
1,000 feet-lb (1356 J) for animals weighing more than 400 lbs

Question 21

What type of gun is generally needed to euthanize animals weighing more than 400 lbs?

Answer 21

Rifles, as handguns do not typically achieve the muzzle energy (1000 feet-lb) needed to euthanize these animals.

Question 22

Generally, when comparing handguns with rifles, how does the barrel length impact muzzle velocity?

Answer 22

Longer the barrel, the higher the muzzle velocity

Question 23

A .22 should never be used on what species?

Answer 23

Aged bulls, boars, or rams

Question 24

What are the three basic types of bullets? Which are preferred for euthanasia, and why?

Answer 24

Solid points, hollow points, and full metal jacket bullets.
Solid point bullets are preferred since they are designed for greater penetration of their targets.

Question 25

Under ideal conditions, what occurs with solid point bullets after penetration? Hollow-point?

Answer 25

Solid point bullets undergo moderate expansion to a mushroom shape that increases its destructive characteristics. Hollow point bullets undergo rapid expansion and fragmentation of the bullet on impact, allowing maximum transfer of energy without risk of overpenetration.

Question 26

When might hollow point bullets be preferred? Why are they typically not preferred?

Answer 26

When desirable to control or reduce the degree of bullet penetration. Concern with hollow points is that, as majority of energy is released on impact through fragmentation, they may not have sufficient energy to transverse the skull.

Question 27

What are full metal jacket bullets designed for? How do they behave on impact? What is the concern for their use in euthanasia?

Answer 27

Designed for maximum penetration. Do not expand or fragment on impact with their target. Creates additional safety hazards for bystanders.

Question 28

Shotguns loaded with what number shot shells have sufficient energy to traverse the skull but rarely exit the skull?

Answer 28

Number 4, 5, and 6

Question 29

Where should the firearm be held relative to the animal? At what angle?

Answer 29

Never flush to an animal's head, as it may cause the barrel of the gun to explode. Ideally held 1-2 feet from the forehead and perpendicular to the skull, with the intended path of the bullet roughly in the direction of the foramen magnum.

Question 30

Cervical dislocation is used on what species?

Answer 30

Small birds, poultry, mice, immature rats (<200 g), and rabbits

Question 31

Describe crushing of the cervical vertebrae and spinal cord in cervical dislocation of birds.

Answer 31

Unacceptable unless the bird is first rendered unconscious.

Question 32

Why is cervical dislocation difficult in heavy rats and rabbits?

Answer 32

The large muscle mass in the cervical region makes manual cervical dislocation more difficult.

Question 33

Why is there controversy regarding consciousness following decapitation?

Answer 33

Electrical activity persists in the brain for 13-14 seconds following decapitation, but studies indicate that this activity does not imply that pain is perceived.

Question 34

What type of current has been used to euthanize animals? What cycle of electrical current?

Answer 34

Alternating current. Fifty- or 60-cycle.

Question 35

How does electrocution cause death?

Answer 35

Cardiac fibrillation, which causes cerebral hypoxia

Question 36

Why must animals be unconscious and insensible to pain prior to onset of cardiac fibrillation?

Answer 36

Do not lose consciousness for 10 to 30 seconds.

Question 37

What are the signs of effective induction of a seizure via passing an electric current through the brain?

Answer 37

Extension of the limbs, opisthotonus, downward rotation of the eyeballs, and tonic spasm changing to clonic spasm with eventual muscle flaccidity

Question 38

How quickly after head-only electrocution must an adjunctive method be performed?

Answer 38

Within 15 seconds of when the animal becomes unsconscious

Question 39

Why might signs of a grand mal seizure be masked when performing the 1-step head-to-body approach with electrocution?

Answer 39

Masked as electric current passes through the spinal cord.

Question 40

What amperages are recommended for electrocution euthanasia?

Answer 40

Pigs and cattle - 1.25 amp Sheep - 1 amp

Question 41

Where can electrodes be placed for the head-only method of electrocution?

Answer 41

1. Both sides of head between the eye and ear 2. Base of the ear on both sides of the head 3. Diagonally below one ear and above the eye on the opposite side of the head

Question 42

How are electrodes placed for the 1-step, head-to-back, electrocution method?

Answer 42

Head electrode placed on the forehead or immediately behind the ear. Never on the neck. Body electrode placed on the opposite side. Behind the forelimb is effective.

Question 43

What type of electrocution electrodes are acceptable for pigs?

Answer 43

A metal band or chain around the nose and a band or chain around the thorax. Pigs up to 125 kg.

Question 44

What signs may be present in animals that have been successfully rendered unconscious with electrocution?

Answer 44

Gasping and nystagmus, not to be confused with rhythmic breathing, vocalization, eyeblink, and tracking of a moving object

Question 45

What size of animals is electrocution not effective in?

Answer 45

Small animals (<5 kg) because ventricular fibrillation and circulatory collapse do not always persist after cessation of flow.

Question 46

When is maceration appropriate for euthanasia?

Answer 46

Poultry up to 27h and embryonated eggs.

Question 47

What is the maximal power output of a focused beam microwave irradiator?

Answer 47

1.3 to 10kW

Question 48

Why is euthanasia with a focused beam microwave irradiator used?

Answer 48

To fix brain metabolites in vivo while maintaining the anatomic integrity of the brain.

Question 49

How rapidly does loss of consciousness and death occur with focused microwave beam irradiation?

Answer 49

<100 ms and death in <1 second