RYEGRASS STAGGERS: CLINICAL, PATHOLOGICAL AND AETIOLOGICAL ASPECTS

Abstract

This paper briefly introduces animal disease aspects of ryegrass staggers IFiGS) and describes the occurence and the clinical signs of the disease. Recent suggestions for the production of a reversible biochemical lesion in the central nervous system are mentioned in relation to the apparent lack of specific morphological lesions found in sheep. The recent isolation of novel potent neurotoxins, the lolitrems, from toxic pasture material is reviewed. There is now strong circumstantial evidence that the lolitrems produce the neurotoxic disease of RGS and also that the lolitrems are elaborated in the close association of perennial ryegrass with its parasitic fungus, Lolium endophyte, in pastures. Under what conditions the lolitrems are produced, or their precise locus within the association, are not yet known.