122 FISTULA AND PGLL-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 any 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 
proportions 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 
