Pasture-Associated Stringhalt in Horses

Last Updated on February 21, 2022 by Allison Price

Pasture-associated stranglehold (PSH), is similar to traditional stringhalt in that it causes exaggerated spasmodic flexions of the hindlimbs. PSH, unlike stringhalt*, also has peripheral neuropathy*. Excessive flexing of the limbs can be exacerbated by turning and backing. Sometimes, the disease is accompanied by a strange hopping gait.

Sometimes, PSH is also known as Australian stringhalt. Although the initial diagnosis was made in Australia and New Zealand for PSH, it has been reported in Asia, Europe and North America.

Hypochoeris.radicata is the most frequently linked to PSH. This plant, also known by false dandelion or flatweed, is also thought to be involved in poor-quality drought-scarred grass. Stringhalt and stringhalt-like gait abnormalities have also been linked to other plants: Lathyrus species sweet peas, Taraxacum (dandelion), Malvaparviflora marshmallow. Stringhalt and PSH are believed to be caused by neurotoxins in these plants, although no specific neurotoxin has yet been identified.

Stringhalt in Horses

False Dandelion is an invasive weed. Because of its long taproot it can resist drought and other difficult growing conditions better than other pasture plants. False dandelion is often last vegetation to die in drought-affected pastures because of its resilience.

It is difficult to treat horses suffering from pasture-associated stringhalt. First, eliminate any exposure to false dandelions. Myotenectomy (myotenectomy) of the lateral digital extendor, botulinum toxinsin infiltration, as well as muscle relaxants are some possible management strategies. A variety of supplements have been tested, including taurine, thiamine, and anti-oxidants (vitamins C and E). These nutritional supplements have not been shown to improve PSH symptoms.

Although many horses are able to recover from toxic exposure, it can take them 6-18 months to fully recover. Mild cases, however, may be more difficult to recover. For severe cases, it may take up to two years for complete recovery. Some horses even never fully recover.

It might not be difficult to avoid PSH by simply making key management changes.

  • PSH is most commonly diagnosed in horses that have access to natural pastures. This can often be during times of drought. Routine fertilizing, reseeding and weed control are all ways to make the most of pastures. To make your pasture as nutritiously rewarding as possible, consult a specialist in pasture management. It can be expensive to renovate pasture, but the rewards in high-quality forage are well worth it.
  • Horses should be provided with alternative forage sources such as free-choice or hay if pasture quality is affected by drought. Research has shown that horses will eat false dandelion, even when there are other pasture plants available. Horses should be provided with something that is more appealing than weeds.
Allison Price
Allison Price

I’m Allison, born and raised in San Diego California, the earliest memory I have with horses was at my grandfather’s farm. I used to sit at the stable as a kid and hang out with my Papa while he was training the horses. When I was invited to watch a horse riding competition, I got so fascinated with riding!