Ryegrass staggers is a disease of grazing animals that causes muscle spasms, loss of muscle control and paralysis. It is caused by a group of toxins that accumulates in the leaf sheaths of perennial ryegrass. The toxins are produced by a native fungus called ryegrass endophyte, Neotyphodium lolii, that grows within the leaves, stems and seeds of perennial ryegrass. Sheep and cattle are most commonly affected but horses, aplaca and deer are also susceptible.
Ryegrass staggers has not been recorded in goats. Affected animals have a stiff gait or are unable to walk. They may injure or kill themselves in transit. The toxins can induce high body temperatures thus animals will try to cool themselves. Younger animals tend to be worst affected. The symptoms of ryegrass staggers usually develop 7-14 days after livestock stock start grazing the toxic parts of the plant. Prolonged exposure to toxic pasture can lead to permanent neurological damage.