Page 826 - Adams and Stashak's Lameness in Horses, 7th Edition

792 Chapter 6

has been obtained in back pain cases with bisphospho- later stage, some cantering can be introduced in circles
nates, especially when osteolysis is present. 6 as well as at the track or over terrain, together with
VetBooks.ir by direct injections of a corticosteroid into or close to muscle contraction. In the author’s clinic, a complete
more strenuous exercises to stimulate more powerful
More localized anti‐inflammatory therapy is obtained
rehabilitation program can easily take 4–6 months, after
the facet joint. The author’s drug of choice is triamci-
nolone (10–30 mg intra‐articularly). The triggering facet which a large number of cases are fully serviceable at the
joint must be established by scintigraphy that shows original level of performance or even higher.
increased uptake of radiopharmaceutical in the area of
the joint, possible radiographic changes, and/or ultra-
sonography that reveals increased vascular activity Prognosis
around the facet joint. With ultrasound guidance, a 20‐ The prognosis for horses with thoracic or lumbar
gauge spinal needle is inserted into the dorsal aspect of facet joint arthritis depends on a number of factors. The
the facet joint, and 10–30 mg of the corticosteroid is discipline in which the horse performs is very important.
injected into or close to the joint capsule. Because the In the racing horse, thoracic facet joint arthritis has a bet-
medication is deposited in the joint capsule or in the ter prognosis than facet joint arthritis of the lumbar facet
adjacent multifidus muscle with an important proprio- joints, whereas the prognosis for thoracic facet joint
ceptive function in intervertebral motion (the multifidus arthritis for a barrel racer may be more performance lim-
muscle stabilizes the spine and facilitates limb motion iting than lumbar facet joint arthritis. Three‐day event
without deformation of the axial skeleton), the use of horses and jumpers often have a more guarded prognosis
sarapin to reduce pain sensation is contraindicated. than dressage horses. In the dressage discipline, rehabili-
Anti‐inflammatory treatment should diminish muscle tation of the core muscles of the trunk can assist in stabi-
spasms, and quite often, muscle relaxation is observed lizing the spine and prevent recurrent injury. Racing
within 2–3 days of facet joint injection. When only sys- trotters seem to have the worst prognosis for full return
temic medication is used, beneficial effects occur more to a racing career when diagnosed with facet joint arthri-
slowly, and muscle relaxation can take up to 2–3 weeks. tis or thoracolumbar pathology in general.
Use of a muscle relaxant such as methocarbamol (15–
25 mg/kg slow IV infusion) can be effective in reducing
the muscle spasm, but the supportive function of the spi-
nal muscles may be diminished, so care must be taken to DISCOSPONDYLITIS
reduce the possibilities for injury to the spinal structures. Etiology
No turnout and a reduced workload are important in a
horse that is on muscle relaxants; however, this may Discospondylitis is an inflammatory condition involv-
compromise an effective rehabilitation program. 29 ing the vertebral bodies adjacent to the symphysis
After reduction of inflammation and the adjacent between two vertebrae, and includes the intervertebral
muscle spasm, the next step in treatment is the design of disc. The most common cause is a septic process, in
30
a rehabilitation program aimed at gaining more mobil- which the infection is caused by hematogenous spread.
ity in the affected part of the spine as well as the devel- The primary site of infection should be identified. Blood
opment of better muscle support for that region. In the flow through vertebral endplate venous channels is rela-
author’s practice, rest is prescribed for 4–6 weeks. tively slow and tortuous, which may promote localiza-
Pasture is ideal, but if the horse is turned out with oth- tion of the infection in the vertebra and spread to adjacent
ers, it must only be with pasture mates that will not discs. Bacteria isolated from cases of equine adult dis-
36
force the patient to run. The more the horse walks, trots, cospondylitis include Brucella abortus, alpha‐hemolytic
1
5
and canters at its own pace, the better the mobility Streptococcus, coagulase negative Staphylococcus, and
achieved. Grazing with the head down opens the facet Staphylococcus aureus. Rhodococcus equi has been
35
joints in the thorax and lumbar region, thus counterbal- implicated in a foal. 4
ancing the spasms in the dorsal epaxial muscles. In Traumatic discospondylitis has been documented in clin-
30
humans, one of the modern rehabilitation techniques ical cases and at postmortem examination. Intervertebral
with tendon and ligament injury is eccentric exercise. disc lesions, including fissuration, calcification, and hernia-
The stretching effect of the grazing position on the dor- tion, have been described ultrasonographically and at post-
sal epaxial muscles as well as the tendons and ligaments mortem examination at the lumbosacral junction and the
around the spine may be a very important side effect of cervical spine. 11
being out in pasture. When a patient cannot go out in
pasture, mimicking this position by feeding small por- Clinical Signs
tions of feed and hay on the ground at multiple times
during the day is a good alternative. Signs of weight loss, back or neck pain, fever, stiff-
After the initial period of rest, a period of gradually ness, and ataxia may all be notable in discospondylitis.
increased work must be incorporated in the rehabilita- Atrophy of the epaxial muscle in the thoracolumbar
tion program. At first, just circling exercises at the walk region may be evident in some horses suffering from
and later at the trot facilitate more lateroflexion, thus chronic discospondylitis in this region. Some horses are
2
providing stretch to the outside part of the spine and so affected that they are reluctant to eat off the ground.
some compression and rotation to the inside part of the Lateral neck flexion can be markedly obtunded as well,
spine. By modulating the size of the circle and the direc- and the abdomen may be held rigid as though intra‐
tion of the circle in a 1‐ to 2‐minute pattern, gradual abdominal pain were present. When compression of
mobilization of the entire spine can be achieved. In a the spinal cord or root nerves is present, neurological