614 Epizootic C't'ix'bro-sjjiiial Meningitis. 



of the brain and medulla. The cerel)rospinal fluid in such cases 

 appears turbid and contains flocculi or fibrin or pus. 



Symptoms. Little is definitely known regarding the i)eriod 

 of incubation. Noack observed symptoms in a horse from a 

 healthy district nine days after its introduction into an infected 

 district. In some cases there are digestive disturbances, loss 

 of appetite, frequent gaping, jaundice (very characteristic ac- 

 cording to some authors). In the horse there may be symp- 

 toms of colic, catarrh of the pharynx and respiratory tract; 

 these being accompanied or followed by gradually increasing 

 depression and dullness which continue to the end. During this 

 period the animals may blunder into objects in front of them 

 and fall down. From time to time there may be attacks of 

 vertigo which may cause immediate collapse. 



S}^llptoms of excitement are observed and these are prin- 

 cipally due to external stimuli. This may manifest itself either 

 as fear, pronounced restlessness, or even in exceptional cases 

 in attacks of mania. For the rest the symptoms of excitement 

 resemble those of meningitis (see pjage 600), although they may 

 not appear until the end. 



Within a short time, and in some cases quite early, spasms 

 occur in certain groups of muscles of the head. There may be 

 squinting, unequal dilatation of the pupils (rare), spasmodic 

 elevation of the ala? of the nostrils and lips. Very frequently 

 there is grinding of the teeth, intermittent trismus, etc. To 

 these is added difficulty in swallowing from the very outset and 

 it may be the most prominent symptom. Animals retain their 

 appetite and take in food and chew it, but are unable to swallow 

 the food or saliva that collects in the mouth, and as result there 

 is a flow of saliva from the mouth. In some cases the food col- 

 lects in the pharynx and causes severe pharyngitis. There are 

 often spasms of the muscles of the neck, the head being drawn 

 back by the tense muscles, and the animal rests with the breast, 

 the lower border of the neck and the chin against the wall. In 

 the horse there are sometimes spasmodic contractions of the 

 muscles drawing the head back. In some cases the contractions 

 are more powerful on one side with the result that the neck is 

 drawn to that side. It is useless to try to overcome the mus- 

 cular cramp and get the neck into the proper position, such at- 

 tempts only increasing the spasms. Not uncommonly there is 

 only a more or less obvious stiffness of the muscles, which may 

 be discovered when attempts are made to move the head pas- 

 sively, and frequently the spasms are quite absent. With the 

 extension of the inflammation along the cord the muscles of the 

 back are similarly affected. In many cases brief contraction 

 of the muscles of the back and other parts of the body are ob- 

 served at short intervals (Schmidt). In many cases the spasms 

 principally affect the extremities and the verteln'al column may 

 be curved throughout its length (opisthotonus). 



