rye grass staggers

1. a neurotoxic disease seen in ruminants in North America, Europe, Australia, and New Zealand after they eat the rye grass Lolium perenne when it is contaminated by an endophytic fungus; characteristics include head nodding, incoordination, limb stiffness, and opisthotonos, all of which soon subside if the animals stop eating the grass. 2. a neurotoxic disease resembling the mycotoxic disease, seen in sheep in Australia and South Africa after they eat the rye grass Lolium rigidum when its seed galls are carrying a nematode infected with species of Corynebacterium. Characteristics include tremor, ataxia, seizures, nystagmus, and opisthotonos, often ending fatally.