Nigropallidal encephalomalacia or Chewing disease is a neurological condition that affects horses that have eaten certain toxic plants.
[1] Because poisoned horses are unable to eat, these animals become weakened and ultimately die of starvation.
[1] The development of the disease typically occurs when the toxic plant is more than 50% of the horse's diet over a protracted period.
[4] The disease appears to be restricted to areas where the causative plant species have become invasive and may represent the only food available.
[citation needed] This article about a medical condition affecting the nervous system is a stub.