Euthanasia Flashcards
what is orthonasia
“ Right Death”, not artificially extend the dying process
what is unconsciousess
Loss of awareness (anesthesia or stunning).
Brain’s ability to receive an integrate information is disrupted
Difference between sedation and anesthesia
Animal is still arousable while sedated, whereas it shouldn’t be if anesthetized (or stunned)
what is depopulation
-Rapid destruction of several animals.
-Emergency (control infectious diseases, catastrophes…)
what is the definition of humane slaughter (4 parts)
-Process and methods to kill animals for commercial reason (food, fur…).
-Applies to both individual animals and large scale.
-Includes transport and handling before unconsciousness and death.
-Not all the slaughter methods meet criteria to be considered euthanasia
3 death mechanisms
-direct depression of neurons necessary for life funciton
-hypoxia
-physical disruption of brain activity
goals of euthanasia
- Achieve irreversible unconsciousness.
- Ideally brain first, followed by cardiac and respiratory arrest.
- Minimize pain, fear and anxiety
can neuromuscular blocking drugs be used on conscious animals
Neuromuscular blocking drugs should never be used in conscious animals
what does the perception of pain require
The perception of pain requires nerve impulses from peripheral nociceptors to reach a functioning conscious cerebral cortex and subcortical brain structures
what two things can happen during euthanasia that you need to warn the owner about
- Post-mortem twitching or movement: occur because the
muscles and nerves go through a short phase of hyperexcitability - Agonal breaths: gasping is a brainstem reflex in response to hypoxia, it is the last respiratory pattern prior to terminal apnea
three death mechanisms
-direct depression of neurons necessary for life function
-hypoxia
-physical disruption of brain activity
how do anesthetics produce unconsciousness
- Reducing information received by the cortical area
- Preventing integration
what does the process of direct depression of neurons lead to
Depression of cortical neuronal system leads to loss of consciousness, followed by respiratory and cardiac arrest.
when can we use inhalants for direct depression of neurons? what are some issues with using it?
- Useful for small animals (<7 kg) or difficult IV access
- Easy to administer (mask, chamber, gauze or cotton)
- Can be used in 2-step euthanasia (induction, followed by injectables)
- Animals may struggle (pungent odor) during induction, sedation helps
- Slow
- Challenging for food-producing animals due to potential for tissue residues
- Not practical for large animals
what are some options related to parenternal injection/topical application/immersion related to direct depression of neurons
- Barbiturates
- T-61: Mixture of embutramide, mebezonium, and tetracaine hydrochloride. Not in the US market, Slow IV injection is necessary to avoid dysphoria prior to unconsciousness
- MS-222 (immersion)
- Ultra potent opioids (IM, wildlife)
- Ketamine/a2 -adrenergic combinations
- Ethanol
what is the most common drug used for barbituates overdose for direct depression of neurons
sodium pentobarbitol
what is the preferred method of direct depression of neurons in domestic species
barbituate overdose
what normally happens with barbituate overdose? what can happen?
- Deep anesthesia progresses to apnea and cardiac arrest.
- Potent, fast, long acting, stable in solution, and inexpensive.
- Agonal breaths are common (sedation).
- FDA approved for dogs and horses.
- Can be irritant; IV preferred, IP and IC acceptable
how is hypoxia achieved
- Hypoxia is commonly achieved by exposing animals to high concentrations of gases that displace O2
- And/or impair oxygen transport by hemoglobin
when can we use CO2 for hypoxia? what can happen? what do we want to achieve and how?
-its acceptable with conditions
- CO2 may cause pain due to the formation of carbonic acid when it contacts moisture on the respiratory and ocular membranes
- Gas displacement rate is critical to the humane application of CO2
- If an appropriate gradual increase % is used, animals will lose consciousness before painful
what species can we use N2 and argon in? what species cant we use it in? how does it work
- Do not appear to be directly aversive to chickens, turkeys, and pigs and appear to reduce, but not eliminate, the behavioral responses to hypoxia
- O2 concentration of <2% unconsciousness in 90 sec, death in 3 min
- Unacceptable for other mammals
how does carbon monoxide work to induce hypoxia? what can it cause?
- Interferes with O2 uptake.
- Induces loss of consciousness without pain and with minimal discernible discomfort, depending on species (rodents, dogs and cats).
- Death occurs rapidly if concentrations of 4% to 6% are used (8-6 min).
- May cause convulsions, agitation and vocalization.
what are some physical methods of euthanasia
-captive bolt
-gunshot
-cervical dislocation
-electrocution
-exsanguination
what is stunning
Stunning is the process of rendering animals immobile or unconscious, with or without killing the anima