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:
- If there is little effect on the animal after 15 minutes (it is alert and reponsive),
give a second full dose
- If the animal is clearly affected but still active after 15 minutes, give a 3/4 dose.
- If there is some degree of anaethesia, but a deeper level is required, give 1/2 dose.
- 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)
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