376 
LACERATED RECTUM OF A HORSE. 
occurring at the time a horse is being “ backraked,” the 
parietes of the intestine giving way from the improper force 
used at the time. We have also known it take place in a 
mare when about to be served by a stallion. It is difficult 
to explain the reason why, but we know practically that from 
such causes as these the animal, as a rule, rapidly sinks, in 
spite of every treatment that can be adopted. 
Partial laceration of the rectum may take place from im- 
pactment, for although this portion of the gut is capable of 
great dilatation, it nevertheless may, from the accumulation 
of fecal matter in it, become so much over-distended as to 
lead to serious results. Some horses will not willingly void 
their feces when being worked at a fast pace, and some, appa¬ 
rently,cannot perform the act even in the walk without stopping 
for that purpose ; and there are doubtless other causes which 
may arrest this act, any of which might be the cause of over¬ 
distension of the gut, thereby tending to partial or total 
paralysis of the muscular coat, and which, if produced, would 
allow of a further accumulation to take place. Under such 
circumstances as these I can understand how, at the time a 
horse is lying down, or from a sudden fall, actual rupture of 
the two innermost coats of the rectum might take place. 
I have conversed with those who are of opinion that inor¬ 
dinate contraction of the muscular coat upon the accumulated 
mass within, independent of other direct causes, is more 
likely to give rise to rupture. I am inclined, however, to 
think the former the most probable cause. 
In the case in question, we find that the laceration was 
confined to that portion of the rectum which is not covered 
externally by peritoneum; therefore, the two innermost coats 
having given way, the external fibro-cellular one would con¬ 
stitute the only means by which the fecal matter could be 
retained. This structure, from its increased vascularity, had 
acquired, on its inner surface, somewhat the character of 
mucous membrane. 
In cases such as the above a cure can never be expected, 
and in those in which a laceration exists to a much smaller 
extent, the probability is that abscesses would form, which 
might result in the formation of incurable fistufe. 
