|
produce a change in gait that is similar and requires a careful diagnosis by a
veterinarian. A gait problem is difficult to identify if the case is mild and has only a hitch
to the forward motion being noticed. If the hoof slaps on the abdomen with each
step then this is an advanced case. For several minutes the leg may be held up
for several minutes and the horse may be unable to move without an awkward
hopping action if both legs are involved.
Horses may not be able to stand if they are severely affected. In chronic cases
muscle loss can occur and sometimes spastic movements can be seen in the
forelimbs as well which is characterized by a toe-scuffing and stumbling
movement.
The true cause of stringhalt has not yet been identified although certain
pasture and climate conditions have been linked to outbreaks.
Horses are at risk if they are grazing in poor pastures that have weeds such as
dandelion, cat’s ear and flatweed. Since simply eating dandelions has not led to
this disease it is believed drought and climate may also play a role.
Ingestion of hay that contains caley pea plants causes lathyrism. Ingestion of
sweet pea plants in poor pastures has been linked to some cases of lathyrism in
the United States.
Another oddity seen in draft horses is shivers. These horses show tremors of the
large muscles of the upper leg and will flex one or both hind limbs. When the
horse is forced to back up or exercise this gait problem is easily seen. No
known toxic plant has been linked to this condition despite the fact that it
resembles stringhalt and lathyrism.
Improvement is possible for some horses with these gait problems, especially if
it is a plant-associated cause and the horse is taken away from the pasture that
is affected. However, more than a year may be required for improvement and in
some cases, especially with shivers, the disease may be progressive and no
amount of care or therapy will be able to help the condition. Good care and
proper nutrition is a part of treatment.
In some non-toxicity cases stringhalt has been cured by cutting a tendon that is
near the hock. However, this only works in the cases that result from the
neuromuscular system and not by those cases that are caused by genetics or
toxicity.
Surgical Treatment for Stringhalt
If stringhalt results from trauma or irritation of the lateral digital extensor
tendon then surgery is usually the preferred treatment in these cases. This
specific tendon attaches to a muscle on the outside of the thigh before
traveling down the leg over the hock joint and then eventually attaching to the
tendons on the front of the foot. It has been postulated that some cases of
stringhalt are caused by trauma and irritation to the tendon in the area of the
hock joint. A piece of the tendon in that area is removed during the surgical
procedure. Under general anesthesia with the horse laying down the surgery for
stringhalt can be performed or it can also be done while the horse is standing
with a tranquilizer.
|
