ENCEPHALITIS. 511 



animal is unable to stand, and dies fighting convulsively, or in a 

 state of profound coma. 



ETIOLOGY. 



It is very generally held by writers upon veterinary medicine 

 that the malady arises from an over-loaded and impacted condi- 

 tion of the stomach, that the cerebral symptoms are purely 

 reflex or sympathetic, and that no actual disease of the brain or 

 its meninges is present. These assertions are not supported by 

 the results of investigation into the morbid anatomy of the 

 malady, further than that the stomach has been generally found 

 filled with food. Now, if engorgement of the stomach were the 

 cause of the train of symptoms seen in this malady, then coma, 

 delirium, or paralysis would be general in the majority of cases 

 of engorgement, seen in the routine of general practice, but this is 

 not the case. Numerous instances of engorgement, impaction, 

 even to rupture of the stomach, constantly come under the notice 

 of the practitioner, but signs of any brain affection scarcely ever 

 occur. We must then look to something more than mere im- 

 paction as the cause, and I think this will be found in the 

 nahire of the food. 



In Scotland it has been called " grass staggers," from the fact 

 that it occurs when the animal is fed on green food ; but ordinary 

 green food does not induce it. I have very carefully noted every 

 case which has fallen under my care for some years, and I find 

 that grass, more particularly rye-grass, when it has commenced 

 to ripen, or when it has been cut, and allowed to heat and ferment 

 before being used, is a fruitful source of this disease. I find that 

 my observations are borne out by those of Professor Dick and 

 others, and that not only horses and cattle are liable to the 

 disease from this cause, but sheep, and especially lambs. 



Mr. Brydon, V.S., Traquair, in a letter to Professor Dick, says 

 that lambs are often destroyed by eating the tops of rye-grass ; 

 and that he has found the tops of rye-grass two or three inches 

 in length in their stomachs, causing inflammation. 



Professor Dick again says — " From what has been stated it will 

 appear that, when rye-grass begins to ripen, a change should be 

 made in the food by placing the animals on other pasture. The 

 grass should be cut before it has quite ripened, as it will be found 

 in that state innocuous." He then refers to a statement made 



