FTK 4: Zoo Animal Anesthesia Flashcards
challenge for working with zoo animals prior to anesthetic procedure?
CANNOT DO HEALTH EVALUATION ON THEM, rely on your own and the keepers’ knowledge/observations
3 things you’re responsible for as a zoo vet?
- veterinary diagnostics/therapeutics
- regulatory testing
- example = TB testing - translocation protocols
- anesthetization, trailer training
3 basic options for zoo animal restraint? what must you keep in mind?
- manual
- sedation
- anesthetic
HUMAN AND ANIMAL SAFETY
ORAL delivery of drugs to achieve sedation? what’s the immobilizing dose? ruminants?
ORAL delivery is based on MUCOSAL CONTACT TIME
- Oral mucosal absorption time»_space;» gut mucosal absorption time
IMMOBILIZING DOSE = GREATER THAN OR EQUAL TO 2X IM DOSE
RUMINANTS HAVE DIFFERENT ABSORPTIVE ABILITIES IN RUMEN
epidural venous injection
what animals have this?
what is it?
what’s it used for?
how to collect?
in animals like SEALS
VENOUS SINUS in the EPIDURAL SPACE
used for DRUG INJECTIONS & BLOOD COLLECTIONS
collect via LUMBOSACRAL PALPATION and insertion of IV CATHETER
hand injection method benefits (4)
- accurate drug PLACEMENT
- know if ENTIRE drug was administered or not
- LESS trauma/stress
- LOWER dose may be required than a DART gun or projectile…
- darts cause stress/pain –> CATECHOLAMINE release –> INCREASED CO –> HEMATOMA formation –> DECREASED drug absorption
3 ways dart trauma can be induced
- the SYRINGE can be too heavy and cause trauma upon impact
- can go to UNINTENDED INJECTION SITE
- face, bone, body cavity, joint - can cause FRACTURE
- through IMPACT
- through BALLISTIC MUSCLE CONTRACTION of a contralateral muscle that then breaks the bone
5 ways to deliver sedation remotely?
- POLE SYRINGE/JABSTICK
- PISTOL/RIFLE
- BLOWPIPE
- CROSSBOW
- PLASTIC SYRINGE
2 mechanisms involved in pistol/rifle use?
- Projection of SYRINGE INTO BARREL
- via compressed AIR/CO2
- explosive charge - Ejection of DRUG into ANIMAL
- via compressed AIR/CO2
- explosive charge
- butane gas
plastic syringe
2 benefits to its use?
1 disadvantage?
structure?
benefits?
1. lightweight
2. cause less trauma
disadvantage?
1. can be affected by wind?
structure?
1. front barrel = DRUG
2. rear barrel = COMPRESSED AIR is INJECTED INTO SYRINGE
safety issues when doing remote sedation
animal? (4)
human? (1)
equipment? (1)
animal?
1. falling –> animals after being sedated move towards hills/gravity
2. drowning
3. paddock design –> if there’s pasture/environment around, animals will try and escape when darted
4. animals in groups will PICK ON sedated members
human?
1. receiving ANIMAL dose is MUCH MORE THAN HUMAN (1, 10, 20 mg/mL vs. 50 MICROgrams)
- DIRECT injections can BOUNCE OFF OBJECTS AND HIT YOU
- USE EYE, FACE, and HAND PROTECTION
equipment?
damages can be EXPENSIVE
is it worse to UNDERDOSE or OVERDOSE immobilizing drugs in zoo animals?
UNDERDOSE! Overall MORE DANGEROUS
can cause…
- longer induction time
- excitement
- stress
- overheating
what are 2 ways we can REDUCE induction time in zoo animals? what other 2 things do these methods reduce?
reduce induction time?
1. HIGH DOSES of drugs
2. HIGHLY CONCENTRATED drugs
what else does it reduce?
1. INJECTION VOLUME
2. SYRINGE SIZE
examples of highly-concentrated drugs? (5, 2 examples for first one)
- Potent opiates
- Etorphine, thiafentanil - Medetomidine
- Midazolam
- Butorphanol
- Ketamine (soluble only up to 200 mg/mL)
“recycling” & renarcotization
“recycling”
enterohepatic recycling = certain drugs will continue to cycle between GUT and LIVER
renarcotization
= in ANTAGONIST drugs, SHORTER half life, so MORE LIKELY TO BE RENARCOTIZED
capture myopathy
= definition
what it causes
= condition that occurs when animal is under prolonged or shortened intense pursuit, capture, restraint or transportation
causes metabolic acidosis, muscle necrosis & cardiac muscle necrosis
hyperkalemia secondary to anesthesia
common in what 2 species?
what can it then cause?
MARINE MAMMALS & LARGE FELIDS
can then cause bradycardia & bradyarrhythmias
what should we first try and do if patient is experiencing respiratory depression? if that doesn’t work, what else can you try?
- INTUBATE & VENTILATE IMMEDIATELY! Monitor & treat
- if not, can use DRUGS…
- specific ANTAGONISTS –> alpha-2 agonists, opiates, benzodiazepines
- STIMULANTS –> doxopram, can be LIFE-SAVING
how to prevent REGURGITATION AND VOMITING in animals?
keep in STERNAL POSITION so that regurgitant material can COME OUT OF MOUTH rather than GO INTO TRACHEA
risks for EARLY and LATE pregnancy when anesthetizing?
EARLY = TERATOGENESIS (cancer-causing)
LATE = FETUS CANNOT BREATHE if exposed to anesthetics
8 qualities in the “perfect” immobilizing cocktail?
- RAPID onset and NO induction excitement
- NO CUMULATIVE effects, so can give another dose without additive effects
- either REVERSIBLE or SHORT RECOVERY TIME
- HIGH MG POTENCY & AQUEOUS SOLUBILITY
- RELIABLE RESTRAINT
- OBVIOUS signs of effect
- GOOD muscle relaxation
- CARDIOVASCULAR & RESPIRATORY STABILITY
what species USE potent opioids for sedation? what about for BAM?
= common for FREE-RANGE LARGE MARINE MAMMALS, BEARS, HOOFSTOCK
can also use BAM (butorphanol, azaperone, medetomidine) on CERVIDS, BOVIDS & HIPPOS
9 adverse effects for POTENT OPIOIDS?
- INDUCTION EXCITEMENT (can be combated with KETAMINE or TILETAMINE/ZOLAZAPAM)
- HYPERTHERMIA
- ACIDOSIS
- RESPIRATORY DEPRESSION
- APNEA
- “STARGAZING” = falling backwards
- REGURGITATION (ruminants)
- RENARCOTIZATION can occur
- MUSCLE RIGIDITY
5 potent opioid combinations & what species they work on?
- ETORPHINE –> zebras, camels, giraffes
- CARFENTANIL –> Eld’s deer
- BAM (Butorphanol, Azaperone, Medetomidine) –> hippos, cervids, bovids
- BMM (Butorphanol, Midazolam, Medetomidine) –> ***MOST SPECIES
- BDM (Butorphanol, Dexmedetomidine/Detomidine, Metetomidine) –> exotic swine
cyclohexylamines
what 3 species does it work on?
what are the 2 drugs most commonly used? (include a warning for the first one, and a common combo for the second)
what are 5 common ADJUNCTIVE agents we can add? what 3 benefits to they provide?
species = CARNIVORES, PRIMATES, HOOFSTOCK
drugs?
1. KETAMINE = causes SEIZURES in WILD CATS
- TILETAMINE (Telazol by brand) + ZOLAZEPAM (Zoletil)
adjunctive agents?
= ANALGESIA, MUSCLE RELAXATION, & RESTRAINT
- CENTRAL ALPHA-2 ADRENERGIC AGONISTS
- DEXMEDETOMIDINE & METOMIDINE have the BEST SELECTIVITY FOR ALPHA 2
- DETOMIDINE > CLONIDINE > XYLAZINE - ACEPROMAZINE
- BENZODIAZEPINE
- ALPHAXALONE
- PROPOFOL
3 common combinations of CYCLOHEXYLAMINES for immobilization (think of benefits/drawbacks & species)
- MEDETOMIDINE + KETAMINE
benefits?
- RAPID & SMOOTH immobilization
- EXCELLENT muscle relaxation
- REDUCE amount of KETAMINE needed via medetomidine
- because ketamine is an ANTAGONIST, RAPID RECOVERY
drawbacks?
- CAUTION –> KETAMINE CAUSES SEIZURES IN WILD CATS & in many species, ABRUPT AROUSAL (20-45 minutes) from ketamine wearing off
what animals can we use this combo on?
CHEETAHS
- TILETAMINE + ZOLAZEPAM (Telazol + Zoletil)
benefits?
- rapid onset
- reliable immobilization
- good cardiovascular stability
drawbacks?
- NOT SUFFICIENT ANALGESIA for long procedure
- LONG recovery when given at IMMOBILIZING doses
- MEDETOMIDINE + TILETAMINE/ZOLAZEPAM
benefits?
- helps DECREASE amount of TILETAMINE needed
- NO sudden arousal
- RAPID REVERSAL
used in FREE-RANGING LIONS
LATE reaction to tiletamine or telazol
what species does this occur in?
what is it? (3-5 clinical signs)
treatment?
species = TIGERS, occasionally lions or other big cats too
what is it?
- 2-5 days after NORMAL recovery, see certain clinical signs
1. ataxia
2. depression
3. DRAGGING hindquarters
4. +/- rigid forequarters
5. +/- seizures
treatment? = MIDAZOLAM OR DIAZEPAM until it WEARS OFF
Yohimbine + Tolazoline have side effects at ___ doses & should not be used in what species? what 3 clinical signs can occur if it IS used in that species?
HIGH
SOUTH AMERICAN CAMELIDS
- heart failure
- acidosis
- seizures
flumenazil
selectivity?
reversibility?
duration?
HIGHLY selective
RAPIDLY reversible
SHORT DURATION, may need to repeat
