17: Bird and reptile anaesthesia Flashcards
Why is any period of apnea a concern in birds?
Low functional residual capacity
Which positions are not good for birds for long periods?
Dorsal or ventral recumbency
Why can fasting debilitate birds?
Poor glycogen storage, esp in liver disease
Above what PCV does a bird need fluids?
55%
For how long do you need to fast birds?
Until crop is empty - 2-3 hours in large parrots, overnight in birds of prey
What can you give birds for a pre-med for minor procedures and diagnostics?
Ketamine with diazepam or midazolam
Why do you not give birds atropine or glyco?
Makes mucus thicker so risk of obstruction
Why don’t you put birds in an induction chamber?
Will flap
Which circuits can you use for birds?
Ayres T piece or Bain
Why don’t you use a cuffed tube in birds?
Complete tracheal rings
How can you intubate a bird if operating on the head?
Abdominal air sac cannulation
How can you monitor bird HR?
Doppler or oesophageal stethoscope
What can still happen to birds even if well oxygenated?
Hypercapnic
What is bird body temp?
39-41
When do you remove the ET tube in birds?
Once jaw tone present
How soon should you offer birds food or water?
Immediately
For how long should you keep birds at a high ambient temp?
Until signs of hyperthermia
What happens to drug metabolism if a reptiles temp drops?
Also decreases
Where does the trachea bifurcate in chelonia?
Just behind the larynx
Why do chelonia have poor lung perfusion if apneic?
Incomplete ventricular septum
Do you need to starve herbivores?
No
How long do you starve insectiores?
18-24h
How long do you starve carnivores?
2-7 days
What can atropine cause in reptiles?
Ileus
What can happen if you make a lizard or snake instead of a chamber?
Apnea
How long can chelonia hold their breath?
45 mins
What are the problems with using ketamine?
Painful, variable response, long recovery, care if dehydrated or renal impairment
What can you add to reduce the ketamine dose?
Diazepam or midazolam
How soon is IV propofol effective?
A few mins
Why do chelonia need IPPV?
Resp movements are by voluntary muscle
How can you avoid overinflation in reptiles?
Moving legs
How fast is a good recovery in chelonia?
30 minutes
Why is it hard to kill a chelonia under anaesthesia?
Resistant to hypoxia
For how long do chelonia need assisted breathing?
Until breathing atmospheric on own, otherwise no CO2 stimulus to breath
What can you give chelonia if they are having a long recovery?
Fluids, keep warm, monitor
What are reptiles very prone to following injection?
Injection site abscess
What can happen to chamaeleons after fluoroquinolone injection?
Pigmentation
Which vein do you use for IV in snakes?
Ventral coccygeal, not heart, R jugular bigger
Which vein do you use in lizards?
Ventral coccygeal (beware autotomy), central coelomic can cause haemorrhage, can do cut-down to reach vein
Which vein do you use in chelonia?
Jugular or subcarapacial
Which bones can you use for IO?
Humerus, tibia, femur, caudal pillar in chelonia
What is a complication of intracoelomic injection?
Can reduce resp movements
What are NOT humane methods of euthanase?
Freezing, decapitation (as CNS can still be aware of painful stimuli as resistant to hypoxia)
What are signs of death in reptiles?
No heartbeat for 5 minutes on Doppler over common carotid, no movement, absent reflexes, autolysis (so come back next day)
How do you euthanise a small reptile?
Gas then barbiturate
How do you euthanise a large snake or reptile?
IM ketamine overdose then barbiturate
How do you euthanise a tortoise?
IV barbiturate
