Enterolithiasis in horses: analysis of 15 cases treated surgically in Saudi Arabia

Background: The equine colic, which is caused by the presence of enteroliths that are most often found in the small or large colon, is typical for certain geographical regions (dry and hot climate). A diet rich in alfalfa is one of the highest risk factors. The earliest symptoms include weight loss and repeated episodes of colic pain. Aims: To present the results of operative treatment of 15 horses with enteroliths in Saudi Arabia. Methods: Fifteen purebred Arabian horses in Saudi Arabia, aged between 2 and 18 years, were treated. Decision about the surgery was based on clinical exam, ultrasound and rectal examination. The surgery was done on recumbent position in every case, under general inhalation anesthesia performed with izofluran. Results: Midline laparotomy was performed in all cases. Additional left flank laparotomy was performed in one horse, in which the stone was located in the proximal part of the small colon and parainguinal laparotomy was performed in 1 horse, in which the stone was located distally in the small colon. In each case, pelvic flexure enterotomy was performed in order to empty the large colon. Additionally, four horses underwent ventral colon enterotomy due to the presence of large stones. Small colon enterotomy was performed in 9 horses. In 12 cases treatment outcome was good and in 3 - poor. Chemical analysis of the stones showed similar results: calcium, calcium oxalate, ammonium, phosphates, and magnesium (Mg) were obtained in all these cases but there were quantitative differences accounting for 15 to 30%, 10 to 20%, 10%, 20 to 40%, and 10 to 15%, respectively. Conclusion: The results of surgery are generally good if stones are located in the large colon, but the prognosis is worse if they are located in the small colon, particularly in its proximal part. There is a huge importance of X-ray examination, which allows accurate diagnosis for locating the enteroliths and making a decision about surgery.