According to Greek philosopher Heraclitus of Ephesus, "There is nothing permanent except change." What he failed to add was, "especially when it comes to colicky horses."

Up to 6% of all colic cases are caused by renosplenic entrapment, which occurs when the large intestine slips up and over the ligament between the left kidney and spleen. Renosplenic entrapment usually causes only mild signs of colic; nonetheless, the intestine needs to be returned to its normal position.

"The most common methods of treating renosplenic entrapments are phenylephrine injection, rolling, or abdominal surgery," explained Dean Hendrickson, DVM, MS, Dipl. ACVS, an equine surgeon and professor at Colorado State University’s College of Veterinary Medicine.

Even with treatment, 3-7% of successfully treated horses can suffer repeat episodes of renosplenic entrapment.

"There are a number of methods to avoid recurrence such as sewing the large intestine to the body wall, removing a large section of the large intestine, or ablating the space between the kidney and spleen," Hendrickson explained. One presumably permanent treatment used to avoid recurrent renosplenic entrapment is "renosplenic space ablation" (RSA, a type of surgery designed to prevent the displacement of the large intestine).

In 2002 Hendrickson and colleagues treated a 7-month-old colt with renosplenic entrapment. They performed an RSA; however, seven years later the horse was diagnosed with another renosplenic entrapment. Surgeons resolved the entrapment and performed a second so-called "permanent" RSA. Three years later, in 2