211 



followed by a paralysis of the whole body, inability to stand, delirium in 

 which the animal sometimes goes through a series of automatic move- 

 ments as if trotting or running; the delirium may become very violent 

 and the animal in his unconsciousness bruise his head in his struggles 

 very seriously, but usually a deep coma renders him quiet until he expires. 

 Death in these cases usually takes place in from four to twenty-four 

 hours from the time the first symptoms became manifest. The pulse is 

 variable during the progress of tlie disease; it may be almost imper- 

 ceptible at times, and then again very rapid and irregular ; the res- 

 pirations generally are quick and catching. When attacked in this 

 rapidly fatal form we may be able only to distinguish it from encepha- 

 litis when other animals in the same stable or neighborhood are simi- 

 larly aflFected. In the next form in which it may develop, it first be- 

 comes manifest by a difficulty in swallowing and slowness in mastica- 

 tion, 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 normal ; the bowels may be some- 

 what constipated. These symptoms may remain unchanged for two or 

 three days and then gradual improvement take place, or the power to 

 swallow may become entirely lost and the weakness and uncertainty 

 in gait more and more perceptible ; then sleepiness or coma may ap- 

 pear ; the pulse becomes depressed, slow and weak, the breathing ster- 

 terous, and paroxysms of delirium develop, with inability to stand, and 

 some rigidity of the spinal muscles or partial cramp of the neck and 

 jaws. In such cases death may occur in from six to ten days from the 

 commencement of the attack. In many cases there is no evidence of 

 pain, spasm, or fever at any time during the progress of the disease, 

 and finally profound coma develops and death follows, painless and 

 without a struggle. 



In the last or mildest form, the inability of voluntary control of the 

 limbs becomes but slightly marked, the power of swallowing never en- 

 tirely lost, and the animal has no fever, pain, or unconscious movements. 

 Generally the animal will begin to improve about the fourth day and 

 recover. 



In a few cases the spinal symptoms, manifested by paraplegia, may 

 be the most prominent symptoms ; in others they may be altogether ab- 

 sent and the main symptoms be difficulty in mastication and swallow- 

 ing; rarely it may affect one limb only. In all cases where coma re- 

 mains absent for six or seven days the animal is likely to recover. 

 When changes toward recovery take place, the symptoms usually leave 

 in the reverse order in which they developed, but local paralysis may 

 remain for some time, rarely persistent. 



One attack does not give immunity, for it may recur at some later 

 time and prove fatal. Horses have been known to pass through three 

 attacks, being affected for a week or longer each time. 



