TREATMENT 89 
age apertures maintained as long as there is 
any issue from them. When the discharge 
continues to be profuse, attempt should be 
made to locate the cause. The main cavity has 
not been drained. If located in an inaccessible 
place, as for example upon the cervical verte- 
bre (cervical fistula) or along the thoracic 
vertebre under the longissimus dorsi, spinalis 
or complexus, it may not be possible to give 
helpful assistance. These secondary abscesses 
are the result of improper treatment or neglect. 
They seldom if ever complicate a well directed 
operation followed by faithful after-care. 
In the case of atypical fistula arising from 
wounds of the back or crest, the operation is 
much the same except that the incision is made 
more posteriorly (Fig. 10). 
It is, however, never advisable to make such 
a median line incision on a thin horse having a 
prominent, sharp withers, as the wound lips 
will sag down below the level of the vertebree 
and produce a condition that will heal very 
slowly and imperfectly. In draft horses with 
thick, low withers there is less danger from this 
standpoint. The fleshy surrounding affords 
ample protection against protrusion of the 
crest above the level of the wound edges, 
