L20: Euthanasia (Shearer) Flashcards
Sentience
Ability to feel or perceive pain, or experience some form of emotion whether positive or negative
-requires a nervous system that is functionally capable of cognition (ie. Thinking) and the ability to emotionally experience its status as bad or good
Objective in humane euthanasia
“Good death” whereby life is ended without pain or distress to the animal
-requires techniques that induce immediate loss of consciousness followed by cardiac and resp. Arrest which results in loss of brain fx and death
For an animal to experience something, it must be both ____ and _____; an unconscious animal experiences nothing
Sentient and conscious
Disadvantages of using barbiturates (non-inhalant agents)
- cost
- requires restraint of the animal
- must be admin. By vet
- carcass disposal complicated by drug residue, and risk for wildlife
Veterinary Medicine Mobility Act
Makes it legal for vets to transport, administer, or dispense controlled substances while providing care outside the locations where those substances are registered
Most common method used for on-farm euthanasia of cattle
- gunshot (classified as physical method)
- effectiveness depends on selection of appropriate firearm, type of bullet, accuracy of aim
- can take 7-10 minutes for heart to stop
- causes less fear and anxiety and induces a more rapid, painless, and humane death
Recommended firearms for euthanasia of cattle
Handguns: 0.32-0.45 caliber
Rifles: 0.22 magnum or higher
Shotgun: 0.410 to 28 gauge (calves), 12, 16, or 20 gauge for cows
*bullets should be solid point
T/F: death is not assured with penetrating captive bolt alone**
TRUE: secondary step is required whenever penetrating captive bolt used (ie. Second shot, exsanguination, pithing, IV KCl)
DOES induce immediate unconsciousness
KCl should never be used as the sole method of euthanasia
Only for use in unconscious animals for the purpose of ensuring death
Main advantage of KCl
No risk to predators/scavengers
Causes of captive bolt failure
- poor maintenance of cartridge
- damp cartridges
- low air pressure in pneumatic stunners
Physical observable parameters of unconsciousness***
- animal collapses immediately
- animal makes no attempt to right itself
- body and muscles become rigid immediately after the shot followed by brief tetanic spasms –> uncoordinated hind limb movements
- immediate and sustained cessation of rhythmic breathing**
- absence of vocalization
- absence of eye reflexes
- eyelids remain open facing straight forward
Optimum position for captive bolt or gunshot for cattle**
- At the intersection of 2 imaginary lines from the lateral canthi to the base of the opposite horns
- approximately 3 inches anterior to the poll in the mature Holstein cow
- halfway on a line drawn laterally from ear to ear
Manually applied blunt force trauma is NOT acceptable method of euthanasia - why?
Skull too hard to achieve immediate unconsciousness and destruction of brain tissue
Unacceptable methods of euthanasia in beef and dairy cattle
- manually applied blunt force trauma
- injection of chemical agents or substances
- injection of xylazine or other alpha-2 agonist followed by KCl or MgSO4
- air injection into vein
- electrocution
- drowning
- exsanguination of conscious animals