Help!!! Horses with stringhalt...who can help?!greenspun.com : LUSENET : Countryside : One Thread
Help!!! does anyone know anything about stringhalt?! i know all the basics, like what it is (a nerve disorder) and such, but i need some more info on it, like if its cureable, and if anyone's horse has had it, i would love to hear from u!!
-- Louise (Voodoo_dolly7@hotmail.com), May 09, 2002
An involuntary flexion of the hock - the leg springs upward in a reflex-like action.
Many horses with stringhalt will flex their hock mildly, while others will jerk their hock harshly up towards their bellies. Some will not show symptoms all the time, while others may show symptoms with every step they take. Watch for these symptoms mostly during turns and while backing. Be aware that these signs may disappear and may show only sporadicly and spasmodicly. In some cases, cold weather has increased these symptoms.
Horses with stringhalt do not have trouble standing up.
The true cause(s) of stringhalt are unknown. Most scientists believe the cause of stringhalt is from certain neuromuscular conditions.
In most cases, the tendon that is causing this involuntary flexion is surgically removed. Most horses improve from this type of treatment. If you see any of the symptoms for stringhalt, be sure to call your veterinarian immediately to examine your horse.
-- Cindy in IL (Ilovecajun@aol.com), May 09, 2002.
There appear to be two types of stringhalt:
1. Sporadic form - in which only one horse is affected. In most cases, the stringhalt gait (exaggerated flexion of the hock) is seen in only one hind leg. Possible causes include a problem in or around the hock (e.g. bone spavin), damage to the front of the cannon and/or the extensor tendon just below the hock (e.g. may occur following a wound over the front of the hock or cannon), a stifle problem (such as locking of the patella), foot pain, and less often, disorders of the hindlimb muscles or spinal cord. Treatment depends on the underlying problem. Horses with this type of stringhalt may improve with a surgical procedure called lateral digital extensor tenectomy, in which a short piece of the lateral digital extensor tendon is removed. (This tendon runs down the outside of the hock, toward the front of the leg, and is one of the structures that flexes the hock.)
2. Outbreak form - in which more than one horse on the same farm may be affected. This condition has been called Australian stringhalt because it was first reported in Australia and it occurs in some parts of Australia every few years. Outbreaks tend to occur during very dry seasons, when there are more weeds than grass in the pasture. Several pasture weeds have been incriminated, but the dandelion (Taraxacum officinale) seems to be implicated most often. There has also been a suggestion that a toxin produced by a soil fungus (a mycotoxin) might be involved.
There have been a few reported cases of Australian stringhalt in the United States. Two papers that I recall involved outbreaks of stringhalt in the northwest (northern California and Washington). The plant incriminated in those outbreaks was flatweed or smooth cats ear (Hypochoeris radicata). It looks a little like a dandelion, with broad, flat leaves and yellow flowers. Another plant that has also been mentioned as a possible cause is mallow plant (Malva parviflora). [And while we're at it, sweet pea (Lathyrus species) toxicity can cause a neurological problem which looks like stringhalt.]
In any case, the toxin damages the longest nerve fibers in the body, which include the nerves that supply the muscles which flex the hock. In most cases, both hind legs are involved, although one may be more severely affected than the other. As this form of stringhalt is caused by a toxin and it has been reported to occur in a single horse when pasture conditions are right, perhaps it should be called the neurotoxic form rather than the outbreak form.
In most cases of toxin-associated stringhalt, the signs disappear without treatment once the horse is removed from the offending pasture. However, it can take several months (sometimes 1-2 years) for severely affected horses to return to a normal gait. In the cases I've seen, most of the mildly affected horses were back to normal within a few weeks; most of the moderately affected horses were substantially improved after several weeks; and only a few of the severely affected horses took months to improve.
Two drugs have been tried, with varying success, in cases of toxin- associated stringhalt: phenytoin (Dilantin) and baclofen (Lioresal). While each of these drugs may improve the symptoms, they do not cure the condition; only time can do that - the damaged nerves need time to regenerate. Lateral digital extensor tenectomy has been tried for this form of stringhalt, but personally I think it's overkill for a condition that, given time, will most likely resolve on its own. Also, the lateral digital extensor muscle is only one of the hock flexors affected by this toxin, so only partial improvement is likely.
This was written by a vet.
Good luck and keep us posted!
-- Cindy in IL (Ilovecajun@aol.com), May 09, 2002.
None of my own horses have had it -- two with it have gone through the barn. Both were treated conservatively to begin with, with excercise regimen designed to increase flexibility, and later with drug therapy. The final upshot was that both cases went surgical and improved markedly, although they were sold off to pleasure rider homes where they wouldn't have to work very hard (altho consistantly to keep them supple as much as possible).
-- julie f. (firstname.lastname@example.org), May 10, 2002.
Thnxs all so much, it has helped me, and i'm pretty sure the horse we thought has stringhalt actually does, the vets confirming this ASAP. although the horse isnt mine, both me and my friend are gratefull to u all on the information u supplied. This isnt the first time i've seen a horse with stringhalt, but the last time i had no say with the horse so i didnt look into it. Thank you all a ton, and i'll keep u updated on Beringa's condition!
-- Louise (Voodoo_dolly7@hotmail.com), May 11, 2002.