46TH
ANNUAL
CONGRESS
OF
THE
SAEVA
SKUKUZA
16-‐20
FEBRUARY
2014
21
Peri-Operative Management of
Donkey Anaesthesia
Dr. J Ferreira. BSc. BVSc. MmedVet (anaes) resident, ECVAA resident
Department of Companion Animal Clinical Studies
Faculty of Veterinary Science, University of Pretoria. South Africa
There are approximately 2 million donkeys found worldwide. The donkey is an icon
of resilience and stubbornness. The role of the donkey in society throughout the
world is highly varied, being used as transport, draught power, companionship and
rehabilitation. In Africa donkeys play an integral role in subsistence farming and thus
are a resource that will require veterinary care and so to then anaesthesia.
As an equine practitioner, the lure will always be to treat donkeys exactly the same
as horses. While in most cases this is true, as with all rules, there are exceptions. In
the case of the donkey there is no more true a statement than that.
There is unfortunately limited literature explaining the differences in the physiology.
Most of the knowledge is either gained through experience or passed on as “hear
say”.
Donkeys are traditionally desert animals. The predominance in this unforgiving and
challenging environment has altered their physiology significantly. Such alterations
have allowed them to withstand great degrees of dehydration without compromising
their physiological homeostasis. Such an example is the ability of the donkey to
withstand body water loss totalling 30% of their body weight. Even more impressive
is the donkey’s ability to restore the deficit within minutes of gaining access to
sufficient water. Urine output no matter the circumstances is lower in donkeys when
compared to horses. Furthermore in the face of heat stress and severe ambient
temperatures the donkey can produce less faecal dry weight than a horse and reduce
faecal water loss.
The hindgut in the donkey is significant in size and function. Acting as a reservoir,
great fluid shifts into the plasma allow the donkey to maintain their plasma volume
even with 20% dehydration. This great store of water in the hindgut may have
implications on the drug distribution or pharmacokinetics. In the same vein the
donkey’s ability to survive on less than optimum forage may be due to altered
metabolism. With such an alteration, the drug metabolism may also be affected.
Anaesthetic and sedative drugs have noticeable differences in effect when used in
donkeys. The reality is the majority of protocols have been assimilated or adopted
from horses. Furthermore the individual variation in size of the donkey plays a
significant role. This can be illustrated by miniature donkeys, which tend to require
higher drug dosages than their larger sized counter parts.
Premedication:
A2- Adrenergic Agonists:
Currently there is very little information available on the use of sedatives in donkeys.
Romifidine, detomidine and xylazine have been described for use in donkeys.
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