History
3-year old Spanish stallion affected by bilateral idiopathic stringhalt in the hind limbs. On the right side, the stringhalt is more severe and the horse, intended for show competitions, is consequently useless and for this reason a surgical consult is requested.
Clinical examination and surgery
The horse presented with excellent body shape and bilateral hind limb stringhalt more accentuated on the right side (Video 1).
The only surgical option was teno-myectomy of the lateral digital phalangeal extensor.
The next day the horse was put on general anesthesia in dorsal recumbency and the right hind limb was accessed in two different points: proximal (muscle) and distal (tendon) to the hock in the lateral aspect. After cutting the tendon, the muscle-tendon unit was stripped manipulating the muscle in the proximal incision. After routine suture (two layers and one layer of the proximal and distal incision respectively), the horse was put in the recovery box. Recovery was uneventful and the horse showed some improvement of the gait when walked to its stall (Video 2).
Follow up
Three months after surgery the horse resumed regular work and the owner was enthusiastic about the result (Video 3).
Comment
Stringhalt is a neuro-muscular disturbance affecting one or both hindlimbs (more rarely front limbs) characterized by hyperflexion of various degrees. In mild cases, it is well evident at walk and tends to disappear at trot and gallop. Is becomes more accentuated when the horse is walked backwards, in turns and in the first steps. It can limit the horse activity or totally preclude it in individuals intended for morphology, show or dressage.
The stringhalt can be congenital, like in the present case, or acquired in horses kept out in pasture and exposed to toxic plants especially in late summer (so called Australian Stringhalt). In the latter form, cases of spontaneous recovery are reported but severe cases are best treated surgically.