Is there a statistical correlation between ultrasonographic findings and definitive diagnosis in horses with acute abdominal pain?

Reason for performing study: Abdominal ultrasonography has become a part of the diagnostic investigation for the acute abdomen in many equine clinics. There is limited information on the correlation between abnormalities detected on abdominal ultrasonography and the specific category of small intestine (SI) and large intestine (LI) diseases.

Objectives: To investigate the relationship between abdominal ultrasonographic findings and disease categories that cause abdominal pain requiring surgery.

Methods: Medical records were reviewed for horses undergoing surgery or post mortem examination for colic. The ultrasound examination was performed to assess free peritoneal fluid, the left kidney, stomach, appearance and motility of the duodenum, identification, appearance, motility and thickness of small intestine loops, and the appearance and motility of the colon. Logistic regression analysis was used to identify associations between disease categories and ultrasonographic findings; a Chi-squared test was used to test for associations between each variable and disease categories.

Results: The study included 158 horses. Distended and nonmotile SI loops were associated with strangulated obstruction (n = 45); increased free peritoneal fluid, completely distended SI loops with abnormal motility and thickened loops were associated with definitive diagnosis involving SI (n = 58). Failure to visualise the left kidney was associated with renosplenic entrapment (n = 16); thickened large colon (LC) was associated with LC strangulating volvulus (n = 9).

Conclusion: The use of abdominal ultrasonography can be used for the accurate definitive diagnosis involving SI and LI diseases.

Potential relevance: This retrospective study may be used as a basis for prospective studies to assess the ultrasonographic findings in horses with medical colic and to compare these with surgical findings.