46TH
ANNUAL
CONGRESS
OF
THE
SAEVA
SKUKUZA
16-‐20
FEBRUARY
2014
23
Table 1: Comparison of Triple Drip Drug dosages as required in a 1-litre Ringer’s
bag.
Drug
Horses
Donkeys
Ketamine
10ml
20ml
Xylazine
25ml
25ml
GGE
50mg/ml (5% solution)
50mg/ml (5% Solution)
The triple drip can be used for maintenance alone or as induction as well. The rate
for maintenance is estimated at 2.0ml/kg/hr and accordingly the drip should last for
90 minutes.
Propofol:
The use of propofol alone and in combination with ketamine provides adequate
induction. The induction time with propofol alone is short at approximately 40
seconds. The dosages of 1mg/kg and 2mg/kg ketamine appear to absolve the negative
effects of using ketamine alone in donkeys premedicated with xylazine. The analgesic
cover is however inadequate with this combination as both induction agents have
shown little or no analgesia. The duration of action of the combination is short and
frequent bolusing or initiation of other modes of maintenance anaesthesia is
warranted for any surgical procedure. Recovery from the combination is smooth.
GGE:
GGE appears to be more potent in horses, with donkeys requiring a 60 % dose of
GGE in comparison to equally weighted horses. This must be kept in mind when
using GGE infusions as overdose is possible and delayed recoveries may occur if the
5% concentration is exceeded.
Inhalant anaesthesia:
The use of inhalant anaesthetics in donkeys is rare, with the majority of procedures
occurring under field conditions. If inhalant anaesthetics are required it is important
to note the anatomical differences with regard to the upper airway of the donkey.
Firstly the ventral meatus of the donkey is much narrower in relation to the horse.
This has implications for placing nasal tubes. This is good practise in the field to
ensure reduction in resistance to airflow achieved in obligate nasal breathers such as
horses and donkeys. Secondly on recovery from prolonged procedures nasal
oedema may occur; requiring a nasal tube to assist in breathing.
For tracheal intubation to facilitate administration of inhalant anaesthetics the follow
anatomical structural differences must be noted:
Firstly; the pharyngeal recess is more extensive in donkeys. Secondly/ the laryngeal
opening narrows ventrally and the angulation of the laryngeal opening is angulated
caudally. All of which increases the degree of difficulty associated with blind
intubation.
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