TECHNIQUE

Medetomidine-Ketamine-Butorphanol Anaesthesia in Rabbits (Disease Investigation & Management - Treatment and Care)

Summary Information
Type of technique Health & Management / Disease Investigation & Management / Techniques:
Synonyms and Keywords --
Description An injectable anaesthetic combination with rapid onset, suitable for short procedures or with anaesthesia prolonged by use of an inhalational agent (volatile anaesthetic).
  • Combine the three anaesthetic agents in one syringe: (B600.5.w5)
    • Medetomidine 0.2 mg/kg plus ketamine 10.0 mg/kg plus butorphanol 0.5 mg/kg. (B600.5.w5)
    • Medetomidine 0.1 mg/kg plus ketamine 5.0 mg/kg plus butorphanol 0.5 mg/kg. (J15.30.w2)
      • Increase ketamine to 10.0 mg/kg for longer (30-40 minutes) surgical anaesthesia. (J15.30.w2)
  • Inject subcutaneously. (B600.5.w5)
    • This may appear to sting in some rabbits. (B600.5.w5)
    • Can also be given intramuscularly, but this causes more discomfort for the rabbit. (J290.29.w2)
  • Leave the rabbit for 5-10 minutes to lose consciousness. (B600.5.w5)
  • If required, intubate the rabbit. (B600.5.w5)
  • Provide supplemental oxygen. (J15.30.w2)

Maintenance

  • If more than 20 minutes of anaesthesia is needed, provide oxygen for 2 - 3 minutes, then introduce a volatile anaesthetic agent via an endotracheal tube or close-fitting face mask. (B600.5.w5)
    • Increase the concentration of anaesthetic agent gradually starting at 0.5%, increasing to 1% after a few minutes then to 1.5%, to reduce problems with breath-holding. (B600.5.w5)
  • Maintain anaesthesia with about 1.5 - 2.5% isoflurane in 100% oxygen. (B600.5.w5)

Reversal

  • If required, atipamezole 1 mg/kg can be given to reverse the medetomidine. (B600.5.w5, J15.30.w2)
  • Note: the effects of atipamezole do not last as long as the effects of medetomidine. Be aware that re-sedation may occur. (B600.5.w5)
  • If no atipamezole is given, recovery occurs by 1 - 2 hours. (B600.5.w5)
Appropriate Use (?)
  • For surgical anaesthesia with pre-emptive analgesia. (J501.43.w2)
  • Maintains stable blood pressure; avoids the low blood pressure which may occur with ketamine plus xylazine. (J501.43.w2)
  • Provides adequate depth and duration of anaesthesia. (J501.43.w2)
  • Rapid reversal is possible by injection of atipamezole. (B600.5.w5)
  • Can be given subcutaneously. (B600.5.w5)
  • Rapid onset of anaesthesia (within 10 minutes of injection). (B600.5.w5)
  • Suitable for short procedures such as radiography or tooth trimming without additional inhalational anaesthesia. (B600.5.w5, J15.30.w2)
  • For longer procedures, can be used for induction and anaesthesia prolonged using a volatile anaesthetic. (B600.5.w5)
  • Complete recovery within three hours even if the medetomidine is not reversed. (B600.5.w5)
Notes
  • If this combination is used for anaesthesia for surgery, it is important that an NSAID is used to provide post-operative analgesia. (B600.5.w5)
  • Can be given intramuscularly, but this causes more discomfort for the rabbit. (J290.29.w2)
Complications/ Limitations / Risk
  • Causes peripheral vasoconstriction. (B600.5.w5, J15.30.w2)
  • Mucous membranes are a pale mauve colour with this combination even with good oxygenation; this could mask cyanosis or shock. (B600.5.w5)
  • Compared with protocols involving fentanyl/fluanisone, analgesia is reduced. (B600.5.w5)
  • Reversal of medetomidine with atipamezole reverses the analgesic as well as the sedative effects of the medetomidine. (B600.5.w5)
  • Produces hypoxaemia; oxygen supplementation should be given. (J290.29.w2)
Equipment / Chemicals required and Suppliers
Expertise level / Ease of Use
  • This procedure should only be carried out by an individual with appropriate clinical training and practical experience.
Cost / Availability
  • Relatively expensive. (B600.5.w5)
Legal and Ethical Considerations In some countries there may be legislation restricting the use of this type of technique to licensed veterinarians. For example in the UK: "The Veterinary Surgeons Act 1966 (Section 19) provides, subject to a number of exceptions, that only registered members of the Royal College of Veterinary Surgeons may practice veterinary surgery." (See: LCofC1 - RCVS Guide to Professional Conduct 2000 - Treatment of Animals by Non-Veterinary Surgeons).

Use of Drugs (Medication):

  • Many drugs are not registered for use in lagomorphs and care should be taken in their use, with proper regard for possible toxic effects. Consideration should be give to relevant legislation regarding the use of drugs.
  • In any country, drugs are unlikely to be specifically licensed for use in non-domestic mammals. 
    • In Europe the prescription cascade must be followed, and the client's informed consent should be obtained, whenever a drug is used which is not licensed for use in a given species. (B284.5.w5)
    • In the UK, guidelines regarding the use of drugs are set out in the Royal College of Veterinary Surgeons Guide to Professional Conduct 2000: (see: LCofC1 - RCVS Guide to Professional Conduct 2000 - Choice of Medicinal Products).
Author Debra Bourne MA VetMB PhD MRCVS (V.w5)
Referee Molly Varga BVetMed DZooMed MRCVS (V.w125)
References B600.5.w5, J15.30.w2, J501.43.w2

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