ANAL FISTULA AND RECTO-VAGINAL FISTULA. oDd 
cases of dilatation or paralysis, the rectum requires to be emptied once 
or twice daily. To combat paralysis all kinds of drugs, the induced 
electric current, &c., have been tried, but without success. Deigendesch 
tried strychnine without good result. 
¥11.—ANAL FISTULA AND RECTO-VAGINAL FISTULA. 
All fistuhe in the neighbourhood of the anus are desciibed as anal 
fistula). Where a communication exists between the skin and rectum, 
the fistula is termed “ complete,” where one end is blind, incomplete. 
Sometimes one end communicates with the rectum, the other with the 
vagina (Fistula recto-vaginalis). The latter is sometimes congenital, but 
also results from injuries, particularly during delivery. 
Injuries and cellulitis of the paraproctal connective tissue are the 
common causes of anal fistula, but the condition may be congenital and 
associated with atresia ani. Operation is the only effective treatment, and 
in the case of recto-vaginal fistulse frequently fails. 
Schrader, in a six year old mare, observed recto-vaginal fistula of a diameter 
of IT inches, about 4 inches in front of the anus.. Meer found a similar one, 
which had appeared after delivery, 3 to 4 inches in front of the anus m a mare. 
Munkel observed in an ox a “complete” anal fistula, the rectal opening 
6 inches in advance of the anus, the second on the lower surface of the tail. 
“ Incomplete ” anal fistula) in horses have been seen by Hertwig ; one was 
12 inches, the other 16 inches in length, and both had resulted from abscess 
formation. Novotny describes a fistula communicating with the rectum, 
and extending between the semi-tendinosus and biceps femons muse es. 
Diagnosis is confirmed by passing a probe or the finger, or both, into 
the rectum, and discovering the opening of the fistula. 
Treatment. To prevent anal fistula, proper treatment of wounds, &c., 
is very important, and injuries of the vaginal walls during delivery must 
receive special attention. # . . 
It is seldom possible to bring about closure by injecting with irritants 
like liquor Villati or disinfecting fluids; and when fistul® extend into the 
rectum or far forwards in the paraproctal connective tissue, the use of 
irritants is dangerous, on account of the possibility of their reaching the 
peritoneal cavity. Operation and free exposure of the fistula are there¬ 
fore preferable. If possible, the sphincter ani must be spared, though 
its section often produces no lasting inconvenience, and union becomes 
quite perfect. Munkel divided the sphincter without bad results; 
Hertwig endeavoured to spare it as far as possible. In laying open a 
“complete” anal fistula a grooved director is inserted, the end of the 
fistula discovered by inserting the index finger of the left hand in the 
rectum, and an incision then made down to the finger, care being taken 
to spare the soft parts as much as possible, and so regulate the cut as to 
A A. 
v.s. 
