CAL: Rabbit and small mammal anaesthesia

Question 1

Name 3 factors that can increase the risk of post-operative ileus in rabbits

Answer 1

anorexia, pain and stress

Question 2

What routine AB tx do some vets advocate peri-operatively in rabbits? 2

Answer 2

Enrofloxacin or OTC

Question 3

List 4 different protocols suitable for rabbit induction of anaesthesia

Answer 3

1. ) Medetomidine (alpha-2 agonist) and ketamine – SC
2. ) Medetomidine and ketamine – IM
3. ) Hypnorm and midazolam – IM
4. ) Propofol – IV to effect

Question 4

Why are rabbits more difficult to intubate than dogs and cats? 4

Answer 4

1. Tongue, cheek teeth and epiglottis are large
2. Laryngeal opening is small
3. Sharp angle between mouth and larynx
4. They may be prone to laryngospasm and laryngeal oedema.

Question 5

What should you do before intubating a rabbit?

Answer 5

inspect the mouth for any food material before intubating (otoscope or laryngoscope. ALWAYS give oxygen before attempting to pass the tube.

Question 6

Method - ‘blind’ technique of rabbit intubation

Answer 6

Sternal recumbency, hold and extend head, pass uncuffed tube into larynx, listen for air flow, apply a spray of lidocaine 1%. If you over-extend the neck you will miss larynx and instead –> oesophagus/stomach

Question 7

How do you check that you have intubated an animal down the trachea rather than the oesophagus? 3

Answer 7

• look for condensation on the inside of the tube
• detect air movement
• use a capnograph

Question 8

Method - using an otoscope or laryngoscope to intubate a rabbit

Answer 8

Select a suitable ETT size, take urinary catheter that just fits the bore of the ETT and cut off the luer fitting. Extend neck, lift animal so chest is just off table OR place in dorsal recumbency with neck extended. Visualise larynx with laryngoscope or otoscope (depress tongue and raise soft palate so vocal cords can be seen). Pull tongue away. Introduce catheter into lumen, remove speculum, leaving the catheter in the tachea, Thread the ETT over the catheter into the larynx. Rotate tube by gently rolling from side to side to get into trachea. Remove catheter and attach to anaesthetic cirucit.

Question 9

Define LMA

Answer 9

Laryngeal mask airway - this is an alternative to passing an ETT for intubation. Another alternative is the V-gel device which is designed specifically for rabbits.

Question 10

Is isoflurane or sevoflurane licensed for rabbits?

Answer 10

Isoflurane only

Question 11

What is the best way to maintain anaesthesia in rabbit?

Answer 11

isoflurane or sevoflurane vaporized in oxygen and delivered via a T-piece.

Question 12

Why do you need to apply lubricant to rabbits’ eyes?

Answer 12

rabbits have very prominent eyes so its important to keep the corneas protected to reduce the risk of developing corneal ulcers.

Question 13

At what depth of anaesthesia is the tail pinch lost?

Answer 13

light to medium planes

Question 14

At what depth of anaesthesia are the toe and ear pinch lost?

Answer 14

medium to deep planes of anaesthesia

Question 15

When is the pedal reflex lost?

Answer 15

very deep anaesthesia - most surgical procedures can be carried out when this is absent or just about detectable.

Question 16

Why is tramadol not the best postop analgesic in rabbits?

Answer 16

not much data on safety in rabbits although it does seem to be effective.

Question 17

Name a good drug combination to provide post-op analgesia in rabbits.

Answer 17

Meloxicam and buprenorphine.

Question 18

What anatomical features of GPs makes them difficult to intubate? 4

Answer 18

Large cheeks: large tongue; narrow oral cavity; soft palate continuous with base of tongue (palatal ostium).