Etiology of Grass Disease

Abstract

IN view of the letter in Nature of May 22 in which W. S. Ferguson recorded a paralysing action of grass juice on the isolated rabbit intestine, it may be of interest to note that we have succeeded, by ligature of the ileum in experimental ponies, in reproducing the main clinical, biochemical and post-mortem findings of acute grass disease. Although in this disease there is no obvious obstruction to the onward passage of fluid from the greatly distended small intestine to the dehydrated contents of the colon, the close similarity between experimental ileal obstruction and the naturally occurring condition suggests that in the latter there may be some functional upset in this region. As the large majority of cases occur in horses at grass, and as the peak incidence occurs during the active-growth stage of the herbage, it is tempting to suggest that the disturbance may be due to some chemical substance either existing preformed in the grass or produced in the process of digestion. Ferguson‘s observations would seem to be well worth following up with this possibility in mind.