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Lateral Digital Extensor Tenecto y 75
thought to be caused by a plant toxin. It has been but the authors have not seen idiopathic cases
identified in Australia, New Zealand, and Califor- improve without surgery, In horses with stringhalt
nia. 3'4 The Australian form and possibly other secondary to dorsal metatarsal trauma, response
fonns of stringhalt have been shown to have an to treatment was reported in nine horses.6 Of the
underlying neuropathy.v" four horses treated with exercise, one resolved,
Conventional, or classic, stringhalt occurs two improved, and one had no change in gait. Of
in individual horses and is typically unilateral. the five horses treated surgically, two resolved, two
The majority of conventional stringhalt cases have had gait improvement, and one had no change in
110 known initiating factors. Some cases are as- gait.
sociated with trauma to the dorsal proximal
metatarsal region, with the suspected etiologies
being adhesion formation involving the lateral REFERENCES
digital extensor tendon and altered myotactic
response due to injury." Other causes of stringhalt 1. Turner AS, Mcilwraith CW: Lateral digital extensor
may be peripheral neuropathy associated with tenotomy. In Turner AS, Mcilwraith CW, editors:
neurologic disease such as equine protozoa! Techniques in large animal surgery, Philadelphia,
myelitis.5 1989, Lea & Febiger.
In one report, a stringhalt-like gait iinproved 2. Sullins KE: Lameness. Part X. The tarsus. In Stashak
after local anesthesia of the tarsometatarsal and TS, editor: Adam's lameness in horses, Philadelphia,
distal intertarsal joints and resolved after intraar- 2002, Lippincott, Williams and Wilkins.
ticular corticosteroid treatment.7 The authors 3. Adams SB, Fessler JF: Lateral digital extensor
have also observed stringhalt-like gaits in horses myotenectomy for stringhalt. In Adams SB, Fessler
with thin soles after trimming and horses with JF, editors: Atlas of equine sitrgery, Philadelphia,
2000, WB Saunders.
hind limb laminitis. These horses have a normal 4. Slocombe RF, Huntington PJ, Friend SCE, et al:
or significantly improved gait on soft footing or Pathological aspects of Australian stringhalt, Equine
after abaxial anesthesia. Vet J 24:174, 1992.
When a horse is presented with a stringhalt- 5. Valentine B: Mechanical lameness in the hindlimb.
like gait, a dietary history, neurologic exam, and In Ross MW, Dyson SJ, editors: Diagnosis and man-
search for identifiable sources of pain should agement of lameness in the horse, St Louis, 2003, WB
be undertaken and treatment is based on these Saunders.
results if indicated. Surgical treatment is generally 6. Crabill MR, Honnas CM, Taylor DS, et al: Stringhalt
indicated for cases of stringhalt associated with secondary to trauma to the dorsoproximal region of
dorsal metatarsal trauma or horses with stringhalt the metatarsus in horses: 10 cases ( 1986-1991), J Am
of unknown etiology. One author recommends Vet Med Assoc 205:87, 1994.
surgical treatment if the gait improves after local 7. Hebert C, Jah11 HW: Intra-articular corticosteroid
a case
treatment for stringhalt in a Quarter horse
anesthetic solution is injected into the lateral report, J Equine Vet Sci 14:53, 1994.
digital extensor muscle. 8 8. Bennet SD: Lameness in the American Saddlebred
With the exception of the stringhalt gait, many and other trotting breeds with collection. In Ross
cases will have an unremarkable history and clin- MW, Dyson SJ, editors: Diagnosis and manage-
ical examination. The iinprovement in gait after ment of lameness in the horse, St Louis, 2003, WB
surgery is difficult to predict for individual cases, Saunders.
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