Page 292 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.7b The axial skeleton – thoracolumbar region 267

VetBooks.ir 1.507 1

2

Fig. 1.507 More subjectively, severe
impingement of dorsal spinous processes
(DSPs) may be associated with lytic
areas and DSP overlap.

1.508

Fig. 1.508 Local anaesthetic injected
into narrowed, or immediate to the side
of, closed kissing spines often results
in a marked reduction in pain and
increased spinal function in affected
horses.

development of cyst-like zones of bone resorption responsive to medication or time off work. Limb
(Fig. 1.507). Where DSPs are in contact, pseudoar- lameness is commonly present in such horses, more
throses and small bursae may form. It is common to often the hindlimbs than the forelimbs. Exceptions
find all grades of disease distributed within one indi- occur and some horses become painful suddenly, for
vidual horse. The associated inter- and supraspinous example following a fall. Symptoms can also develop
ligaments also become disrupted. The source of pain following a period of scheduled time off, or enforced
in these affected horses is still unclear and may vary rest, apparently occurring suddenly when riding
considerably in individual cases. Local anaesthetic re-starts. Clinical signs correlate poorly with the
infiltrated into the narrowed spaces alleviates the number of impingements or the perceived severity of
pain transiently, implying that sensory nerves in the radiographic signs. Achieving a good saddle fit can
the local soft tissues are a significant source of pain be problematic and lead to exacerbation of back pain.
(Fig. 1.508).
Differential diagnosis
Clinical presentation Soft-tissue and bone trauma; saddle pinch or pres-
The symptoms of back pain have been discussed sure; vertebral facet disease; supraspinous desmitis;
earlier in the chapter. Many cases present as chronic ventral spondylosis; upper hindlimb lameness; foot
back pain with epaxial muscle wastage, intermittently imbalance.