Phalaris staggers is a serious and sometimes fatal disorder that occasionally shows up in sheep grazing on Phalaris aquatica (P. tuberosa), less frequently for other Phalaris species, and almost NEVER with Phalaris aruninacea.
When it does occur, as in the case with Phalrais aquatica, the losses can be quite high. Although Phalaris staggers have been described in the literature for over half a century and intensely "studied" for several decades, the actual cauative factors for this syndrome are, at best, poorly understood and, in most cases, misrepresented.
The research surrounding Phalaris staggers is still characterized by far more confusion, worthless ddata, questions and conjecture than either understanding or answers.
Phalrais staggers has three primary manifestations; an acute form that may terminate in either the rapid collapse and death of an animal, or else, and USUALLY; full and rapid recovery without incidient, or a chronic form from which the animal only slowly, and often never fully recovers, and which is accompanied by degenerative changes in the liver and portions of the central nervous system. The chronic form has also resulted in death, but at some time later.