Page 833 - Adams and Stashak's Lameness in Horses, 7th Edition

Lameness Associated with the Axial Skeleton 799

RADICULOPATHY
When one or more segmental root nerves in the cervi-
VetBooks.ir cal spine are compressed, damaged, or irritated due to
trauma or enlarged facet joints, lameness symptoms
may occur. In these cases, blocking of the distal limb
5
nerves will give a negative outcome. Physical exam
might show a reduced mobility in the neck, but some-
times the musculoskeletal exam is uneventful. The neu-
rological exam however will show clear signs of nerve
impingement with loss of skin sensitivity in the affected
area, while often the adjacent segments show an augmented
response to skin sensitivity testing. Ultrasonography can
be a useful tool in identifying enlargement of the soft
tissues of the cervical facet joints with enlargement of
the synovial membrane and joint effusion when radio-
graphs are not showing clear indication of affected cer-
vical facet joints. Imaging using Doppler can identify the
most affected region.
Osteoarthritis of facet joints, especially in the more
caudal aspect of the cervical spine or cranial thoracic Figure 6.43. Radiographic image of the cervical spine. Note the
spine, may result in an associated enlargement of the change at the caudal aspect of the end plate of C5 and the small
joint capsule and subsequent pressure to the spinal cord fragment (left circle) when compared with the clean appearance at
or root nerves. Oral dexamethasone may be used to C6 (right circle). This not only is most likely caused by trauma to the
reduce this swelling and the signs of nerve compression, intervertebral ligament at the ventral base of the spinal canal but
or infiltration of the epidural space with corticosteroid also can be caused by local mineralization within the intervertebral
disc. In the acute stage, swelling can cause neurologic symptoms
can be performed. 11 related to compression of root nerves or the spinal cord.

DISCOSPONDYLITIS
stall rest or confinement in a small pen or paddock to
As described in the section on the thoracolumbar reduce motion. However, callus formation can cause com-
spine, discospondylitis can occur in the cervical spine, pression of the root nerves or the spinal cord in a later
most likely in the caudal cervical vertebrae. Signs of stage, and fractures of facet joint surfaces often result in
neck pain and front limb stiffness or lameness may be facet joint arthritis. Trauma to ligamentous structures and
present. Diagnosis can be made with radiography and the intervertebral disc may be not visible on initial radio-
scintigraphy, and the prognosis is guarded. 3,4,14 graphs (Figure 6.43) and can easily be overlooked or not
recognized, but may result in discospondylitis, spondylitis,
or osteoarthritis in a later stage.
CERVICAL FRACTURES
As described earlier in this chapter, fractures of cervi-
cal vertebrae can occur, and in nearly all cases this is due References
to severe trauma. Fractures of facet joint surfaces are 1. Butler J, Colles C, Dyson SJ, et al. The spine. In Clinical Radiology
rather common, but laminar fractures and fractures of of the Horse, 2nd ed. Blackwell Science, Oxford, 2000.
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been described. Depending on the location and the sound‐guided injection of the cervical vertebral facet joints in
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Therapy in Equine Medicine, 4th ed. Robinson NE, Wilson MR,
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can assist in determining the extent and location. In spe- poor performance. Vet Clin North Am Equine Pract 2011;27:
417–437.
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from 7 to 10 days after the injury, when displacement of umn of horses walking on a treadmill. Kinematics of the equine
the fracture and recognition of the fracture line are difficult back during locomotion. PhD Thesis, Utrecht, 2001.
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month‐old foal. Equine Vet Educ 2009;21:71–75.
examination of the cervical spine is an option but pri- 8. Hudson NPH, Mayhew IG. Radiographic and myelographic
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an interpretation of larger fractures through the body or cord. Equine Vet Educ 2005;2:43–48.
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When there is no damage to the spinal cord or the adja- 2007;10:460–462.
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movement of the head and neck in the trotting horse—a pilot
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