purposes, the animal will also normally be sedated with an appropriate sedative or
tranquillising drug (Dobromylskyj et al. 2000 ). Infiltration of local anaesthesia has
been used in all domestic species, from cattle to cats. Another widely used local
anaesthetic technique in veterinary medicine is that of regional peripheral nerve
blockade. For dental procedures in dogs, cats and horses, selective blockade of the
distal branches of the cranial nerves is commonly utilised, whilst blockade of the
auricular nerves is often performed in association with aural surgery (Buback et al.
1996 ). The cornual nerve is blocked for disbudding and dehorning procedures in
cattle, and a more extensive blockade is recommended in cases of antler removal in
deer (Johnson et al. 2005 ). In dogs and cats brachial plexus block is used to
facilitate forelimb surgery (Nutt 1962 ) and for the hind limb the various lumbar
and sacral nerves can be targeted. A paravertebral nerve block using the sites of exit
of the spinal nerves from the intravertebral foramina is commonly used in the
thoracic and lumbar regions of cattle to allow abdominal surgery to be performed in
standing animals and this is of great benefit to both the animal and the surgeon
(Cakala 1961 ; Moon and Suter 1993 ). Local blocks of limb nerves in horses have
been used as a diagnostic aid to identify the source of pain in lame animals. Another
veterinary use of local anaesthetics is that of intravenous regional anaesthesia.
This has been reported for use in the paws of dogs and the feet of cattle (Skarda
1996 ), when the limb extremity is isolated by a tourniquet, and the local anaesthetic
is administered intravenously distal to the tourniquet. The limb extremity is then
desensitised for surgery, following which the tourniquet is removed and sensation
returns over the next 20–30 min. Finally, the use of local anaesthetics at the spinal
level, to provide epidural anaesthesia, has been recorded for use in animals as long
as in humans (Cathelin 1901 ; Sicard 1901 ). Much of the information on epidural
administration of local anaesthetics in animals is very similar to the data in humans,
with the more lipid soluble drugs possessing a longer duration of action associated
with slower absorption into the systemic circulation (Table 1 ) (Catterall and Mackie
1996 ). The longer duration of action of the lipid soluble anaesthetics is preceded by
a slower onset of action.
Epidural administration of local anaesthetics has been documented in most
domestic mammals (Torske and Dyson 2000 ) and there is no reason why it should
not be as effective in non-mammalian species, although there are no reports of such
use. Normally care is taken with local anaesthetics to avoid inadvertent intravenous
administration and the consequent risk of cardio depressive effects. However, there
have been reports that constant rate infusions of local anaesthetic may provide
Table 1Epidural actions of local anaesthetics in the dog
Drug Onset (min) Duration (min)
Lignocaine 2% 5 45–90
Mepivacaine 2% 5 60–90
Bupivacaine 0.5% 20 120–360
Ropivacaine 0.5% 15 90–420
All drugs administered at 0.2 ml/kg. Data from Torske and Dyson
( 2000 )Pain and Analgesia in Domestic Animals 175