122 FISTULA AND POLL-EVIL 



ed above the surrounding level. The head, at 

 first extended from the pain of the forming ab- 

 scesses, gradually becomes fixed in the extend- 

 ed position from fibrous anchylosis of the re- 

 gion. An animal affected with poll-evil has a 

 characteristic attitude simulating the opisthot- 

 onos of tetanus. 



Poll-evil that becomes infected before there 

 is an}^ enlargement of the region must be diag- 

 nosed sometimes entirely from this attitude 

 and from the pain produced by manipulating 

 the head. 



Rare cases cause epiliptiform seizures when 

 the head is moved about manually or in work- 

 ing. In such instances when local evidence is 

 entirely lacking because of the depth of the 

 infected focus it may not be an easy matter to 

 arrive at a diagnosis. 



The development of poll-evil is always grad- 

 ual, although it may often assume considerable 

 projDortions before attracting attention. The 

 mane and forelock shelter the region so effec- 

 tually in some animals that the enlargement 

 develops unnoticed until discharges appear. 

 These cases are, however, rare, as the pain and 

 the position of the head which precede the dis- 

 charge are usually pronounced enough to at- 

 tract attention. 



The average poll-evil when submitted to the 



