Page 1348 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Wound management and infections of synovial structures 1323

VetBooks.ir 13.41 synovial infection. However, using a heavy analgesic
regime could potentially mask clinical deterioration
or recrudescence of the infection, and the clinician
should titrate the analgesic protocol to the minimal
dosage needed.

Restoring synovial homeostasis
The restoration of synovial homeostasis occurs with
time once the inflammatory process has subsided.
If the damage inflicted has been severe, synovial
homeostasis may never be fully reached. The intra-
synovial administration of hyaluronic acid provides
anti-inflammatory effects and helps restore normal-
ity. Passive rest followed by hand walking, starting
once the acute inflammation has subsided, is also
Fig. 13.41 Distal limb regional perfusion of beneficial. Systemic and/or oral glycosaminoglycan
antibiotics can be carried out in the standing sedated supplements may be useful.
horse. Note the tourniquet placed on the forearm
proximal to the carpus and the intravenous catheter in TENDON LACERATIONS
the cephalic vein.
Flexor tendons
Flexor tendon lacerations commonly affect the
Reducing inflammation and providing superficial and/or deep digital flexor tendons and,
analgesia on rare occasions, other tendinous structures as well
The benefits of adequate analgesia cannot be over- (Fig. 13.42). The clinician should promptly identify
emphasised. Comfort allows the animal to ambulate the characteristic appearance of a distal limb that
and diminishes potential complications associated has lost flexor support. In cases where the suspen-
with pain and lack of movement such as impaction sory ligament has also been severed or torn, the fet-
colic, overuse injuries of other limbs and adhesion lock will be dramatically dropped (Fig. 13.43). In
formation in cases of intrathecal infections. The most cases where palmar/plantar support has been lost or
common NSAIDs used are phenylbutazone, flunixin severely compromised, providing immediate support
meglumine and ketoprofen. Any of these seem to for the distal limb is mandatory, because failure to
work adequately, although the author favours the use do so may predispose to hyperextension of the limb,
of phenylbutazone (2.2–4.4 mg/kg q24 h, depending resulting in overstretching of the palmar/plantar
on the response to therapy). In cases that are severely blood vessels and severely compromising the vascu-
painful, or where NSAIDs may not be indicated, the lar supply.
use of opioids should be considered. Epidural mor- Flexor tendon lacerations in the forelimb may
phine (0.01–0.3 mg/kg) is useful for the hindlimbs. occur as a result of overreaching injuries in race-
Systemic opioids (e.g. butorphanol 0.02–0.1 mg/kg horses. These injuries are commonly associated with
i/m or i/v q4–6 h) on their own, or in combination small wounds; however, wound size does not correlate
protocols (e.g. ketamine 0.5–1 mg/kg with metha- with damage severity. Laceration of the flexor ten-
done 0.05 mg/kg i/m q4–8 h) can help control pain dons may occur either within (intrathecal) or outside
generally. Alternatively, fentanyl patches (2–4 10 mg (extrathecal) the tendon sheath. This is an impor-
patches q72 h; forelimbs) provide good analgesia tant distinction, because the clinical management
and comfort superior to NSAIDs. Analgesia also and prognosis vary according to the location of the
permits early ambulation, which may have a very injury and whether only the superficial digital flexor
positive effect on the rehabilitation of horses with tendon and/or the deep digital flexor tendon and/or