Catching and Handling of Dormice (Wildlife Casualty Management)

Summary Information
Type of technique Health & Management / UK Wildlife Casualty Management / Techniques:
Synonyms and Keywords N.B. N.B.  This information should be read in association with Wildlife Casualty Handling and Transport which contains background information together with links to the Electronic Library and Organisations (UK Contacts). The related Species pages contain similar linkages.
Description This page has been prepared for the "UK Wildlife: First Aid and Care" Wildpro module, and is designed for the needs of the following species: Muscardinus avellanarius - Hazel dormouse, Myoxus glis - Fat dormouse

These species are from the family Myoxidae.

Catching and Handling:

Muscardinus avellanarius - Hazel dormouse

  • Rarely aggressive; may be caught and picked up by hand. (B151)

Myoxus glis - Fat dormouse

  • A net (fine mesh size) or a humane catching cage may be used to catch these animals in an enclosed space.
    • Fine mesh size on the net minimises the risk of the animal becoming entangled in the net.
  • Grasp the head and neck firmly through the net before carefully working the net off the animal.
  • May be transferred directly from a net into a suitable container without direct handling if examination is not required.
  • Thick gloves are sometimes recommended to provide protection from bites, which can reach bone. In many cases gloves will not be sufficiently thick to prevent bites reaching the hands but at the same time will greatly decrease the sensitivity and security of grip; loss of dexterity and grip security with thick gloves may be a particular problem if the wearer has small hands and if the gloves are not supple.
  • (B123, B151).

Restraint for Examination and Treatment:

  • Examination of Muscardinus avellanarius - Hazel dormouse may be carried out using physical restraint.
  • Treatment of Muscardinus avellanarius - Hazel dormouse which requires the animal to be kept stationary, as well as any procedures which may be painful, should be carried out under general anaesthesia.
  • Examination and treatment of Myoxus glis - Fat dormouse may require general anaesthesia.

General Anaesthesia and Sedation:

 Suggested protocols for sedation and general anaesthesia include:

  • As with other small mammals general anaesthesia may be induced in an anaesthetic chamber.
  • Mask induction of general anaesthesia may also be used, but this can lead to handling stress.
  • Isoflurane is the anaesthetic agent of choice.
  • Halothane may be used as an alternative to isoflurane.
  • Maintain on isoflurane inhalation anaesthesia with oxygen (no nitrous oxide), delivered via a face mask e.g. made from a plastic syringe barrel.
  • Use a low-resistance circuit such as a T-piece.
  • Allowing some leakage from the face mask further reduces resistance;
    • Some form of active scavenging should be used to reduce atmospheric pollution.
  • Avoid excessively high flow rates of oxygen, as this increases heat loss and the risk of hypothermia.
  • Consider fluid therapy during general anaesthesia of small mammals to replace water losses; subcutaneous fluids would be appropriate.
  • Action should be taken to reduce heat loss of small mammals during general anaesthesia, to reduce the risk of hypothermia e.g. keep on a heated pad during anaesthesia and recovery.
  • (B205)
  • Starvation prior to general anaesthesia should not be performed in these species.
Appropriate Use (?)
  • Catch only if necessary.
  • Handling of wild animals should be minimised.
  • Consider design of accommodation and timing of treatments to minimise requirements for capture and handling.
  • Consider whether physical or chemical restraint is more appropriate.
  • Minimise handling to minimise stress.
  • Rodents often struggle violently when restrained.
  • Fine mesh size on net minimises the risk of entanglement in the mesh.
  • Thick gloves may provide some protection from bites of Myoxus glis- Fat dormouse but will reduce dexterity.
  • During general anaesthesia, allow some leakage from the face mask to reduce resistance.
  • Keep on a heated pad during general anaesthesia and recovery to reduce the risk of hypothermia.
  • Fluid therapy should be considered during general anaesthesia of small mammals, in order to replace losses; subcutaneous fluids would generally be appropriate.
Complications/ Limitations / Risk
  • Risk of injury to the animal if struck by the hoop of a net.
  • Risk of entanglement of e.g. claws in the net.
  • Bites from Myoxus glis - Fat dormouse can reach bone.
  • Risk of hypothermia during general anaesthesia.
Equipment / Chemicals required and Suppliers
  • Appropriate net and gloves, if required.
  • Humane catching cage if necessary for Myoxus glis - Fat dormouse.
Expertise level / Ease of Use
Cost/ Availability
  • Suitable cloths such as towels are widely available.
  • Nets may be obtained from specialist suppliers, veterinary suppliers or good pet stores; their cost is variable.
  • Gloves and glass jars are widely available.
  • Nets may be hand-constructed from readily-available inexpensive materials.
  • Some drugs used for chemical restraint are expensive.
  • Drugs used for chemical restraint may only be available to veterinary surgeons or other licensed persons.
Legal and Ethical Considerations
Author Debra Bourne
Referee Becki Lawson and Suzanne Boardman

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