Discussion

Klohnen, A.
Aims: Post operative ileus (POI) has traditionally been associated
with small intestinal lesions. There is new evidence to suggest that
in horses, primary lesions involving the large colon can result in
small intestinal dysmotility. This retrospective study was performed
with several objectives: to determine the prevalence of post
operative ileus in horses undergoing colic surgery for non-small
intestinal related lesions and to determine the short-term survival
for this group of horses. Methods: The medical records of horses
undergoing exploratory celiotomies between June 2004 and
September 2010 at Chino Valley Equine Hospital were reviewed.
Data analysed included surgical lesion, development of ileus and
survival to discharge. Ileus was defined as the identification of
nonmotile distended loops of small intestine based on repeat
ultrasonographic evaluation, with or without nasogastric reflux.
Results: Nine hundred and eighty-eight (92%) horses undergoing
colic surgery survived to the initial 24 h period; 569/988 (58%)
of horses had non-small intestinal lesions as the primary cause of
colic; 493/569 (87%) of these cases had a primary large colon
lesion, 34/569 (6%) had a primary caecal lesion and 42/569 (7%)
had a primary small colon lesion. Of these 569 non-small intestinal
cases, 83 developed post operative ileus, diagnosed via
ultrasonography. Reflux was only obtained in 9 of these cases.
Forty-four of 486 horses (9%) in the nonileus group died or were
subjected to euthanasia after the initial 24 h period; 22/83 horses
(27%) diagnosed with post operative ileus were subjected to
euthanasia after the initial 24 h period. Four of 83 horses with
post operative ileus required repeat exploratory celiotomies; only
one horse in the non-post operative ileus group required repeat
surgery. Significantly more horses survived to discharge in the
nonileus group compared with the horses treated for ileus.
Conclusions: This study has identified POI is not uncommon in
horses with primary large colon lesions.