CEEEBROSPINAL MENINGITIS (" FORAGE POISONING"). 3 



practitioners recognized the disease as their old torment — cerebro- 

 spinal meningitis, staggers, or forage poisoning. 



The latter name came into the literature of the disease as a 

 s3nion3rm in 1900 following the investigation of an outbreak by 

 Pearson. He was able to reproduce the disease in experiment 

 horses by feeding them on damaged silage, and by giving them 

 water to drink which had percolated through this silage. Doubtless 

 influenced by the frequent absence of microscopic lesions of the 

 central nervous system, and by the analogy between this disease 

 and meat poisoning of man, Pearson proposed the name forage 

 poisoning, which has been more or less in favor ever since. There 

 are certain objections to this term, principally from the fact that it 

 may suggest a form of poisoning produced by vegetation that is 

 specifically poisonous, such as lupines, loco, larkspur, etc., or by 

 ordinary forage that is poisonous of itself. This, however, was not 

 the intention of Pearson, for by his analogy to meat poisoning it is 

 evident that he did not wish to convey the impression that all forage 

 was poisonous any more than all meat is poisonous. But when 

 meat becomes contaminated with pathogenic bacteria, such as the 

 Bacillus enteritidis, B. hotulinis, etc., such meat is dangerous to 

 man in the same manner that ordinary forage contaminated with 

 certain unknown infective agents becomes dangerous to horses and 

 produces forage poisoning. In other words, the forage is the carrier 

 and not the primary factor in the disease. On the other hand, 

 this term has a direct advantage in being readily understood in 

 popular usage and in convejdng to the layman's mind that an 

 absolute change in feed is essential. 



After years of study and experimentation it is the consensus of 

 opinion of practically all investigators that the disease can be con- 

 trolled effectively only by a total change of feed and forage; in other 

 words, by preventive measures and not by medicinal treatment. 

 That there is direct connection between ingestion of green forage, 

 exposed pasturage, newly cut hay and fodder, and the development 

 of the disease is quite obvious, and that the ingestion of such forage 

 when contaminated is the most important factor is equally obvious, 

 as almost ,100 per cent of the cases in Kansas and over 95 per cent 

 of the cases in Nebraska of which we have any record were maintained 

 all or part of the time under such conditions. Even such negative 

 history is not always dependable, as the owner on one farm informed 

 the writer positively that the dead horses had eaten nothing except 

 old hay and grain, but when notice was taken of the closely cropped 

 grass in an adjacent pasture he innocently remarked that he always 

 turned the work horses into the pasture over night. In fact in some 

 sections ''pasture disease" is the designation for this malady. 



