Page 286 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.7b The axial skeleton – thoracolumbar region 261

VetBooks.ir Differential diagnosis this technique is contraindicated for deeper peri-
spinal structures owing to the risk of spinal injec-
Abnormal function caused by poor riding technique,
heavy riders and poor fitting saddles. Lameness, par-
means of locating chronic perivertebral pathology,
ticularly of the hindlimbs, has been shown to lead tion. Gamma scintigraphy provides a less invasive
to asymmetry of back movement and rider. It may but unless the soft-tissue damage has changed local
also cause the saddle to move asymmetrically, to bone physiology, false negatives will be encountered.
slip and rub (termed saddle slip), thereby causing Where logistics or finances preclude scintigraphy,
secondary back pain. Traumatic injuries of muscles, or results prove equivocal, diagnostic therapy using
nerves and ligaments, especially the supraspinous the methods outlined below can provide an effec-
and interspinous ligaments, can occur. The trauma tive alternative. Before proceeding with diagnostic
is not always observed, which makes differentiation therapy, it is crucial to ensure total understanding
from more insidious conditions more difficult. Bone and cooperation from the owner since, by definition,
injuries, including DSP impingement, facet joint diagnostic therapy may prove negative.
disease, stress and other fractures, and ventral spon-
dylosis, can all present in similar ways to soft-tissue Management
injuries, and as previously noted may have concur- Superficial ulcers and rubs usually respond quickly
rent secondary soft-tissue injuries. Infections such to basic wound management. Deeper saddle galls,
as fistulous withers, discospondylitis and neoplasia especially those nearer the midline, are sometimes
are occasionally encountered in specific age groups. most easily managed by surgical excision of scar tis-
Reported rare causes include other forms of visceral sue, carried out standing under local anaesthesia.
pain, such as nephrolithiasis, cyclic ovarian activity, After appropriate wound management, saddles and
gastric ulcers and mesorchium tension. Aortic or tack should be checked carefully to ensure a good fit
iliac artery thrombosis. Other causes of poor per- before riding resumes.
formance, especially limb lameness. Behaviour and If the damaged ligament or muscle can be accu-
temperament problems. Dental problems. rately located, then targeted treatment is possible.
Corticosteroids, sometimes combined with pitcher
Diagnosis plant extract (sarapin/saragyl), have been injected
Diagnosis of acute superficial trauma may be made directly into ligaments using ultrasound guid-
visually. Where focal trauma has occurred, ultra- ance and reported to be of use. Where inflamma-
sound and radiographic assessment often can iden- tion is present this is helpful symptomatically, but
tify the cause. Injection of small volumes of local excessive corticosteroid is associated with ligament
anaesthetic into identified pathology can help mineralisation and is potentially counterproduc-
ascertain their relevance, but care should be taken tive (Fig. 1.495). Focused extracorporeal or radial-
in how this is interpreted. The anticipation and pulsed shock-wave therapy provides an alternative
compensation for focal pain may not resolve, while targeted analgesic treatment for ligament injuries.

1.495

Fig. 1.495 This horse had repeated
corticosteroid injections in the
interspinous ligament over a period of
several years. Note the mineralisation in
and around the top of the interspinous
space (arrows).