| 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: Martes
martes - Pine marten, Mustela
erminea - Stoat, Mustela
nivalis - Weasel, Mustela
putorius - Polecat, Mustela
vison - American mink. These species are within the family Mustelidae.
Handle with caution, wear stout leather gloves: these animals will
bite and hold on and bites may be severe.
Catching and handling:
- It may be possible to tempt animals of these species to enter a drainpipe leading into a
box, as for ferrets; this would allow an individual to be caught and transported without
any direct handling. (D25)
- Handle with caution, wear stout leather gloves: these animals will bite
and hold on and bites may be severe.
- The animal may be gripped quickly with gloved hands around its neck and forequarters.(B199,
D25)
- The animal may be restrained with one hand holding the back of the neck and the other
extending the hind legs and tail.(B16.7.w7)
- Nets may be used for restraint of these species.(B123)
(B16.7.w7,
B123,
B199,
D25)
- A dog grasper may be used to handle Martes
martes - Pine marten, Mustela
putorius - Polecat, Mustela
vison - American mink:
- slide the dog grasper to just behind the forelegs of the animal;
- once the grasper is in position, use it to quickly lift the animal and deposit it inside
a suitable container.
- (B151)
Restraint for examination and treatment:
- Manual restraint of these extremely agile and fast-moving animals is difficult.
- Examination and treatment are best performed under general anaesthesia.
- Crush cages may be used for restraint of the larger species to allow intramuscular
injection e.g. for induction of general anaesthesia.
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:
- General anaesthesia may be induced using an induction chamber;
- Isoflurane is a suitable anaesthetic agent and may be used for induction and for
maintenance of general anaesthesia. (B205,
D24,
P20.1992.w1)
- Halothane may also be used. (B205,
P20.1992.w1)
- A prolonged time to induction of general anaesthesia has sometimes been reported when
using gaseous anaesthetic agents delivered by induction chamber for the induction of
general anaesthetic in aquatic species which have the ability to breath-hold for extended
periods.(P20.1992.w1)
- General anaesthesia may also be induced using injectable anaesthetic agents such as
ketamine; or ketamine combined with midazolam, diazepam, xylazine, medetomidine or
acepromazine (P20.1992.w1).
- Ketamine (5-10mg/kg) intramuscular is suggested for restraint of mink.(B123)
- Ketamine 20-30mg/kg intramuscular is suggested for stoats and weasels.(B205)
- 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)
- The effects of medetomidine are normally reversed by injection of the agent atipamezole,
unless otherwise indicated. (V.w5,
V.w6,
V.w26)
- Ketamine 25mg/kg plus diazepam 25mg/kg intramuscular is suggested for stoats and
weasels. (B205)
- Alphaxalone/alphadalone (Saffan, Schering Plough Animal Health) 10-15mg (total
steroid)/kg intramuscular is suggested for stoats and weasels.(B205)
- Intubation of mustelids is relatively easy.(P20.1992.w1)
- 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.
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