TECHNIQUE

Catching and Handling of Lutra lutra - European otter (Wildlife Casualty Management)
Click image for full page view

Summary Information
Type of technique Health & Management / UK Wildlife Casualty Management / Techniques:
Synonyms and Keywords 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: Lutra lutra - European otter
  • Otters are extremely supple and very strong. They can be difficult to catch unless severely incapacitated by injury.
  • Approach and handle with caution: otters are capable of inflicting severe bites. (J60.2.w3, B151)

Catching and Initial handling:

Otters will attempt to escape into water if possible. Capture attempts should be planned to prevent the otter reaching the water.

  • May be caught with a net.
    • A hand-net with a padded rim to reduce the risk of damage to teeth.
    • A piece of heavy netting thrown over the animal.
  • If an otter is apparently unconscious, check that it is really unconscious by touching the head with a soft-headed broom, paying particular attention to the effects of stimulating around the sensitive areas of the eyes and mouth.
  • If the otter is truly unconscious, securely pin the head and neck to the ground with the head of a soft-headed broom.
    • While it is pinned, a second person may scruff the otter securely using both hands and immediately place in a suitable container.
  • If the animal struggles free, catch with a padded-hoop net.
  • Conscious animals may be grasped initially with a dog grasper around the neck and one foreleg (B151); or around the body just behind the front legs.(B199)
  • Pick the animal up by holding the loose skin of the rump in one hand (supporting most of the animal's weight), the dog grasper in the other, and place in a suitable container; close the lid then release and bring out the grasper before finishing closing the container. (B151)

(B123, B151, B199)

Restraint for examination and treatment:

  • May be restrained using an appropriately-designed crush cage for e.g. intramuscular injection.
  • A soft-headed broom may be used for restraint for injection, although otters, being very strong and supple, may be able to wriggle out from under this.
  • Adults are best examined under general anaesthesia unless collapsed or unconscious.

(B123, B151, B199, D24)

General Anaesthesia and Sedation:

General Information:

  • Combination of intramuscular medetomidine and ketamine is commonly used for general anaesthesia in small and zoo animal practice in the UK; extrapolation of dose rates for companion animals from the manufacturers recommendations may be appropriate. Manufacturer's recommendations for feline general anaesthesia include "[Medetomidine] Domitor [Pfizer Limited] should be administered at a rate of 80mcg/kg [intramuscular] with a concomitant dose of 2.5 - 7.5mg/kg [intramuscular] of Vetalar [Pharmacia and Upjohn Ltd.] or Ketaset [Fort Dodge Animal Health](ketamine)." (B202) In extrapolating dose rates a number of issues must be remembered:
    • higher dose rates may be required for very nervous / excited / agressive animals who may initially over-ride the effects of anaesthesia
    • smaller animals with a higher metabolic rate may require proportionally higher dose rates; the reverse is also usually true for larger animals
    • collapsed, shock and/or dehydrate animals may required lower dose rates
      (V.w6, V.w26)
    • Sometimes there may be a requirement for additional "top-up" doses of injectable anaesthetics (V.w6, V.w26) and the following should be considered:
      • ideally, if a mask can be applied without excessive stress on the animal, masking it down with either isoflurane or halothane is usually the best option.
      • it is not desirable to reach the situation where additional doses are being given in order to reach initial stable anaesthesia whilst the first drugs are wearing off. It is all too easy to overdose in this situation. If three injections are not effective - if possible, it is highly advisable to stop the procedure, allow the anaesthesia to wear off and then repeat the procedure at a later date using higher doses initially.
      • when increasing dosages, careful consideration should be given both the side-effects of the drugs and the availability of reversal agents
      • If an intravenous injection can be given, it may allow more control over the depth of anaesthesia
      • if a top-up dose is required, the following rule of thumb is recommended:
  1. If there is little effect on the animal after 15 minutes (it is alert and reponsive), give a second full dose
  2. If the animal is clearly affected but still active after 15 minutes, give a 3/4 dose.
  3. If there is some degree of anaethesia, but a deeper level is required, give 1/2 dose.
  4. Beyond that - use best judgement.

(V.w6, V.w26)

Suggested protocols for sedation and general anaesthesia include:

  • Intramuscular combinations of tiletamine and zolazepam (Zoletil; Virbac); medetomidine (Domitor, Farmos [Pfizer Limited], ketamine (Ketaset, Willow Francis [Fort Dodge Animal Health]) and midazolam (Hypnovel, Roche Products); medetomidine and ketamine; and zolazepam, tiletamine and medetomidine have been described in this species [dose rates not specified]. (J3.143.w4).

  • For general anaesthesia the following protocol has been used efficiently and safely:

    • Combination of intramuscular medetomidine and ketamine.
    • Intramuscular injection in a conscious animal may be given while it is being physically restrained by means of a crush cage or by remote injection e.g. blow-pipe.
    • Once administration has taken place the otter should be left in a quiet dark place to allow the drugs to take effect.
    • (V.w26, V.w6)
  • The effects of medetomidine are normally reversed by injection of the agent atipamezole, unless otherwise indicated. (V.w5, V.w6, V.w26)
  • In collapsed animals, general anaesthesia may be carefully induced using isoflurane supplied by a face mask. Great care with restraint should be taken to avoid injury to personnel.
  • Combination of ketamine with a sedative (e.g. benzodiazepine, alpha-2 agonist) is generally preferable to the use of ketamine alone. (V.w5, V.w6, V.w26)
  • Combination of ketamine with a benzodiazepine may be preferable to its combination with an alpha-2 agonist in sick or collapsed individuals because of the more limited cardiovascular depression associated with the former agent. (V.w5, V.w6, V.w26)
  • Gaseous [general] anaesthetic agents (such as isoflurane) may be administered by mask to anaesthetise cubs.
  • Intubation is straightforward and recommended.
  • Isoflurane or halothane may be used to prolong [general] anaesthesia following the use of injectable anaesthetic agents.
  • The length of starvation prior to induction of general anaesthesia should be appropriate for the species in question and the likelihood of regurgitation. Clinical judgement should be used as to the pros and cons of starvation in an emergency situation. Starvation may not be appropriate for small species with a high metabolic rate which must eat frequently to survive.
  • (V.w5, V.w6, V.w26)
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.
Notes
  • Otters are very strong and safe physical restraint may be difficult.
  • In some situations, particularly where an animal can be easily targeted, the use of darting techniques may greatly decrease the stress of capture when compared with physical capture combined with hand-injection. In using darting techniques, the following points must be remembered:
    • The size of needle, volume and viscosity of the fluid and the amount of power used to project the dart should be appropriate to the size of the muscle mass and thickness of the skin. The use of inappropriate equipment and materials can cause serious damage to the animal.
    • Darting should only be undertaken by experienced personnel holding the requisite UK firearms licence.
  • (V.w6)
Complications/ Limitations / Risk
  • Otters are extremely supple and very strong. They can be difficult to catch unless severely incapacitated by injury.
  • Approach and handle with caution: otters are capable of inflicting severe bites. (J60.2.w3, B151)
Equipment / Chemicals required and Suppliers
  • Dog grasper
  • Crush cage
  • Soft-headed broom
Expertise level / Ease of Use
  • Experience is important for the safe handling of these animals. Inexperienced persons should contact someone with the appropriate expertise for advice and assistance.
Cost/ Availability
  • Appropriate nets, dog grasper, squeeze cages may be available from specialist suppliers or veterinary suppliers; some of these items may be relatively expensive.
  • 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
  • Risks to human health, both physical and risks of zoonotic illness, must be considered (Health and Safety at Work, etc. Act 1974).
  • Lutra lutra - European otter is listed on Schedule 5 and Schedule 6 of the Wildlife and Countryside Act 1981. It is an offence (Section 9) to "take" i.e. capture any animal on Schedule 5 of this Act. However, there is an exception (under Section 10) for a disabled animal which is taken "solely for the purpose of tending it and releasing it when no longer disabled." (W5.Jan01) It is an offence (Section 11) to "take" (i.e. capture) any animal on Schedule 6 using a variety of methods (snares, traps etc.) including "any net". (W5.Jan01)
  • See: Legislation relating to Wildlife Casualties.
Author Debra Bourne
Referee Becki Lawson and Suzanne Boardman
References

Return to Top of Page