Nephrosplenic entrapment of the large colon in 142 horses (2000-2009): analysis of factors associated with decision of treatment and short-term survival.

Reasons for performing study: Previous studies indicate similar overall survival of horses with nephrosplenic entrapment of the large colon (NSE), regardless of treatment strategy. Short-term survival of a primarily conservative treatment strategy without rolling under general anaesthesia (GA) and a low proportion of surgical intervention as well as indicators of short-term nonsurvival has not been documented.

Objectives: To document short-term survival of horses with NSE treated in a university referral hospital with a low rate of surgical interventions and to determine factors associated with the decision of treatment and short-term nonsurvival.

Methods: A retrospective review of medical records of 142 horses diagnosed with NSE between January 2000 and October 2009 was undertaken. Case details and clinical parameters from the initial examination, treatment and outcome were recorded. Factors associated with decision of treatment and short-term survival were identified by multiple logistic regression analysis.

Results: Warmblood breeds were over-represented in comparison to the general colic population. Overall short-term survival was 91.5% (130/142) which is similar to previous studies. Three horses considered to be in need of surgery were subjected to euthanasia for economical reasons before treatment. Of 114 conservatively treated horses, 110 (96.5%) survived, as did 20/25 (80%) of surgically treated horses. Nine conservatively managed horses were treated with phenylephrine. Gastric reflux (P = 0.0077), pain (P = 0.024) and abdominal distension (P = 0.05) were associated with the decision to treat surgically. Increased heart rate (P<0.001), and surgery (P = 0.032) were associated with reduced likelihood of short-term survival.

Conclusions and potential relevance: Overall short-term survival was similar to that reported in previous studies with higher proportions of surgically managed cases. Consequently, horses with NSE should be managed by a primarily conservative treatment strategy, with the decision to treat surgically based on specific evidence based criteria.