Anaesthesia of exotic species Flashcards
What are groups of birds with specific concerns regarding anaesthesia?
- Ratites (ostrich, emu, etc)
- Cranes
- Flamingos
- Charadriiformes (waders)
- Penguins
- Marine/diving birds
What are general considerations of anaesthesia?
- High incidence of chronic + subclinical disease
- Susceptible to heat loss + hypothermia -other than penguins + marine birds
- Small birds = difficult venous access, limited anaesthesia monitoring
- > mobidity / mortality
What birds do not have nostrils?
- Cormorants, pelicans, gannets
In what bird is the glottis not easily visible?
- Flamingo
What is the difference with CV system of birds?
- Higher HR + BP
- Higher tolerance to haemorrhage and anaemia
How would you prepare a patient for anaesthesia?
- Weight
- Complete clinical exam
- Fasting for larger birds
- Correct fluids prior to anaesthesia
- Eye lubricant
What should be checked for on pre-anaesthetic exam?
- Mentation - hypoglycaemia (bradycardia + hypotension), Dyspnea, neuro disease
- Mucus membranes - pigmented in several species
- African grey parrots - hypocalcaemia (routine supplement of calcium pre-anaesthesia)
What are indications for sedating birds? what can be used?
- Clinical exam if needed
- Short procedures - blood sampling, x-rays, beak trim
- Pre-med for anaesthesia
- Midazolam + butorphanol
- reverse with Flumazenil
What can be used for anaesthesia in birds?
- Alfaxalone
- Propofol - limited by IV access
- Alpha-agonists (medetomidine) - combine with ket, reverese with atipamezole
- Parasympatholytics (Atropine) - only in bradycardia / CPR situations
If operating on a bird in a field what can be used?
- Midazolam + butorphanol = sedation
- Ketamine + medetomidine = anaesthesia
What analgesia can be use in birds?
- NSAIDS = Meloxicam
- NOT - Flunixin meglumine, Ketoprofen, Diclofenac
- Opioids - Butorphanol, Buprenorphine, Fentanyl, Tramadol
- Gabapentin
What can be used for local anaesthesia?
- Combination of =
- Lidocaine
- Bupivicaine
What are different venous access in birds?
- Medial metatarsal vein - poultry, waterfowl, larger species
- Ulnar (brachial vein) - medium to large species - prone to haematomas
- Intra-osseous catheters - smaller species
Why wound you not use induction chambers for gas anaesthesia in birds?
- Risk of self-trauma
- Dead space
What can isoflurane cause in birds of prey?
- Induces arrhythmias
- tachycardia
- Hypertension
What is important with supportive care during GA?
- Ventilation - 6bpm
- Fluids
- Temperature = all birds lose heat rapidly - heat sources
What can be done to monitor patients under GA?
- Direct observation =
◦ Palpebral/Corneal reflex
◦ Wing tone
◦ Feather plucking reflex
◦ Deep pain/toe pinch reflex
◦ Sudden feather erection > cardiac arrest - Heart rate = values +/- 20% of baseline - Doppler probe
- RR = chest movement
- Blood pressure
- Temp - cloacal probes
- Capnography
What is the window for resuscitation in birds?
<30seconds
What is normal approach to most complications?
- confirm ETT is patent / non-obstructive
- Stop anaesthetic gas
- Start IPPV
- Hypertonic saline - until BP >90mmHg
- Crystalloids + colloids
- Consider Dextrose 50%
- Atropine
- Start chest compressions
- Adrenaline
What should be done for recovery?
- stop anaesthetic gas + provide O2
- Remove IV/IO catheters
- Check glottis for mucus build up
- Incubator
What are key points of lizard anaesthesia?
- Poikilothermic - can’t regulate own temp
- Disease process frequently subclinical + chronic
- Long recoveries
What is different with lizard CV system?
- 3 chambered heart - 2 atria + 1 ventricle
- Renal portal system - blood from caudal half body can reach kidneys
- hepatic portal system - blood from caudal half of body passes through liver before general circulation = drugs metabolised by liver should be admin on forelimbs
What are reptiles and tortoises very tolerant to?
- Myocardial hypoxia
- Diving reflexes in aquatic reptiles
How would you prepare a reptile for anaesthesia?
- Full clinical exam
- Weight
- Keep patients under POTZ
- Fasting - 2-3hrs for most species, 1-2days for snakes + chelonians
- Eye lubricant
What are different options for sedation of reptiles?
- Midazolam + opioid
- Dexmedetomidine + midazolam
- Alfaxalone
- Ketamine - snakes
- Isoflurance in induction chambers
If animal is breath holding what can be administered to reduce it?
- Atropine
What injectables can be used for induction?
- Ketamine + dexmedetomidine
- Propofol
- Alfaxalone
How can you monitor anaesthesia in reptiles?
Reflexes:
◦ Rightening
◦ Palpebral
◦ Corneal (present but impossible to assess in snakes and some lizards)
◦ Tail, toe, cloacal pinching
◦ Head withdrawl + neck tone (Chelonia)
◦ Tongue withdrawal (Snakes + monitor lizards)
◦ stroking ventral scales
HR:
◦ Doppler over heart – location varies!
◦ ECG
What can be used for analgesia in reptiles?
- Opioids = Butorphanol, Morphine, Hydromorphone, Methadone, Tramadol
- Meloxicam
- Local anaesthesia = lidocaine, bupivicaine
What are general considerations of exotic mammal anaesthesia?
- Most are prey = stress
- Obligate nasal breathers = rabbit / rodents
- Prone to hypothermia
How would you prepare exotic mammals pre op?
- Weight
- Full clinical exam
- No fasting
- Correct fluids, meds
- Always lubricate corneas
What can be used for pre-med?
- Midazolam + butorphanol
How can you monitor anaesthesia?
- HR
- BP
- Capnography
- Reflexes - Rightening, corneal, palpebral, ear pinch, pedal withdrawal reflex
Where would you administer IV catheter in a rabbit / ferret?
- Marginal ear vein = rabbit
- Cephalic vein = ferret
