238 DISEASES OF THE HORSE. 
This condition consists in a poisoning and depression of the ner- 
vous system from eating or drinking feed or water containing poison 
generated by mold or bacteria. It has been shown to be owing to 
eating damaged ensilage, corn, brewers’ grains, oats, etc., or to drink- 
ing stagnant pond water or water from a well contaminated by sur- 
face drainage. Horses at pasture may contract the disease when 
the growth of grass is so profuse that it mats together and the 
lower part dies and ferments or becomes moldy. 
In England a similar disease has been called “ grass staggers,” due 
to eating rye grass when it is ripening or when it is cut and eaten 
while it is heating and undergoing fermentation. In eastern Penn- 
sylvania it was formerly known by the name of “ putrid sore throat ” 
and “ choking distemper.” A disease similar in many respects which 
is very prevalent in Virgina, especially along the eastern border, is 
commonly known by the name of “blind staggers,” and in many of 
the Southern States this has been attributed to the consumption of 
worm-eaten corn. Horses of all ages and mules are subject to this 
disease. 
Symptoms and lesions.—The symptoms which typify sporadic or 
epidemic cerebrospinal meningitis in man are not witnessed among 
horses, namely, excessive pain, high fever, and early muscular 
rigidity. In the recognitign of the severity of the attack we may 
divide the symptoms into three grades. In the most rapidly fatal 
attacks the animal may first indicate it by weak, staggering gait, 
partial or total inability to swallow solids or liquids, impairment of 
eyesight; twitching of the muscles and slight cramps may be ob- 
served. As a rule, the temperature is not elevated—indeed, it is 
sometimes below normal. This is soon followed by a paralysis of 
the whole body, inability to stand, delirium in which the animal 
sometimes goes through a series of automatic movements as if trot- 
ting or running; the delirium may become very violent and the un- 
conscious animal may bruise his head very seriously in his struggles; 
but usually a deep coma renders him quiet until he expires. Death in 
these cases usually takes place in from 4 to 24 hours from the time 
the first symptoms become manifest. The pulse is variable during 
the progress of the disease; it may be almost imperceptible at times, 
and then again very rapid and irregular; the respirations generally 
are quick and catching. In the next form in which this disease may 
develop it first becomes manifest by a difficulty in swallowing and 
slowness in mastication, and a weakness which may be first. noticed 
in the strength of the tail; the animal will be unable to switch it or 
to offer resistance when we bend it up over the croup. The pulse is 
often a little slower than normal. There is no evidence of pain; the 
respirations are unchanged, and the temperature little less than nor- 
mal; the bowels may be somewhat constipated. These symptoms 
