Combining 'Best' of Two Surgical Techniques for Right Dorsal Colitis

Veterinarians from the University of Pennsylvania's New Bolton Center saved a 14-year-old Warmblood gelding with right dorsal colitis by combining two surgical techniques to remove the diseased part of his bowel.

The horse had been treated with the non-steroidal anti-inflammatory drug (NSAID) Banamine (flunixin meglumine) for more than a month for an eye problem when he developed colic because of the NSAID use.

The surgeons decided to do surgery when the horse did not respond to the usual medical treatment of right dorsal colitis, which includes:

  • stopping treatment with NSAIDs;
  • giving pain medication as needed, but not NSAIDS;
  • modifying the diet by using pelleted feed instead of hay or not feeding the horse by mouth and providing intravenous (parenteral) nutrition; 
  • administering misoprostol, corn or safflower oil, psyllium HCl (Metamucil); and
  • providing additional supportive care, such as IV fluids as needed.

The affected part of the bowel was deep within the abdomen, making it difficult to remove (resect) all of the affected colon and put the healthy ends back together (anastomose). Contamination of the abdomen with ingested feed and failure to remove all of the affected colon are two problems with this technique, said surgeon Louise L. Southwood, BVSc, PhD, Dipl. ACVS, ACVECC.

However, the surgeons did not want to do just a bypass technique where they leave the affected colon in place and reroute ingested feed around it because the horse might remain in pain. Furthermore, horses' blood protein often remains low with this technique because of protein loss from the affected colon.

"Normally, a surgeon performs either a resection and anastomosis or bypass. Because the inherent problems with these techniques, we performed a resection and bypass," she said. In the area that was to be removed, the surgeons applied staples across the 2 ends of the healthy colon to remain in the abdomen and across the affected colon that was to be removed. Cuts were then made between the rows of staples and the damaged part removed (the resection).

But this created two unconnected ends. "We could not leave it as two unconnected ends because ingested feed would not have made it through the horse's intestinal tract. Therefore, we bypassed the resected area (i.e., went around the two unconnected ends) in an area of bowel that we could easily reach from the incision," she said.

Southwood said she would recommend this combined technique if a horse does not respond to medical treatment, especially if he shows signs of persistent pain.

"It can be challenging to determine when to do such a procedure because you do not want to wait until the horse is debilitated because recovery could take longer and be more complicated," she said. "But at the same time this surgery should be reserved for horses that are truly not responding to medical treatment. Medical treatment can be prolonged and discussion with the veterinarian treating your horse is important."

Medical treatment will help most horses with right dorsal colitis, if diagnosed and treated early. However, Southwood recommends avoiding future use of NSAIDS or considering the newer COX selective or preferential NSAIDs.

The study, "Right dorsal colon resection and bypass for treatment of right dorsal colitis in a horse," was published in online ahead of print in Veterinary Surgery.

The abstract is available on PubMed.

About the Author

Marie Rosenthal, MS

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