Readers reacted with shock and disappointment at Tuesday's news of the death of Ben's Cat, four-time Maryland Horse of the Year and fan favorite, from complications related to colic. The gelding had undergone surgery July 6 for an epiploic foramen entrapment, a complicated condition with high risk of complications.
Although the timing of his colic was especially frustrating, coming soon after his retirement earlier this year, veterinarian Dr. Rana Bozorgmanesh, who treated the multimillionaire at Haygard Equine Medical Institute in Kentucky, said the two events are not related.
Epiploic foramen entrapment refers to part of the small intestine becoming caught in a gap between several internal organs. It is the discomfort from this misplacement of the intestine that causes the classic colic signs of increased heart rate, sweating, pacing, pawing, etc.
Veterinarians don't know what causes epiploic foramen entrapments, but they are not associated with changes in routine, diet, or other stress factors, the way the common gas or impaction colics can be. Research has found horses who crib or wind-suck seem to be at added risk for epiploic foramen entrapments, but we still don't know why.
Unfortunately, this type of colic can become complicated quickly after onset and in many cases, the surgery to repair the entrapment is invasive.
Bozorgmanesh said the part of the intestine that's stuck out of place is at risk of losing function because it's likely not getting its full blood supply. If the intestine is still uncompromised at the time of surgery, surgeons can untangle it, examine it, and put it back into place with the hope it will regain normal function. If not, they must remove the damaged portion – which Bozorgmanesh said happens in the majority of cases for this type of colic.
“If you imagine it kind of like a garden hose, you have to cut a section out and sew the two ends back together,” she said. “When you have to actually cut some out and sew the ends back together, there's a higher risk of complications.”
Potential problems with resecting part of the intestine aren't unlike potential problems with resecting a garden hose. For one thing, the area sewn back together could leak, releasing gut contents into the body, ultimately causing infection. This area could fail to regain its normal diameter, which increases the chance digestive material could slow or get stuck there. Endotoxemia can also occur if bacteria and their toxins in the intestine leaks into the blood stream when the intestine was first trapped and damaged.
“The other immediate issue is because of vessels in that area you can sometimes get hemorrhage, either pre- or post-operatively,” Bozorgmanesh said.
In addition to these risks, the intestines often become inflamed when disrupted by surgery, and this increases the chance they will stop moving material through (a condition called ileus), which can spark another bout of colic.
“You can imagine that in a procedure where you've actually had to cut some of the intestine out and re-sew the ends together, you have an increased risk of ileus because that's a more invasive procedure than just pulling the intestine out of where it was stuck,” she said. “Post-operative ileus is something we deal with quite a lot. Because horses can't vomit and the intestine isn't working, you get backflow of the digesta and you have to pass a tube, and you'll reflux the horse until the inflammation has died down.”
Typically, the more intestine is removed in a surgery like this, the less likely the horse is to recover.
These complications, if they're going to arise, do so relatively early in the case. But even assuming a horse can get through the time immediately post-surgery with no problems, there are additional concerns.
Fibrous bands called adhesions can also form in response to the inflammation that occurs in the abdomen, and depending on their location, they may compromise the intestine months or years after the surgery. Infection at the incision site is always a concern, as is laminitis. It's thought a horse recovering from this type of colic may get laminitis as a result of endotoxemia from the early stages of the entrapment.
“You may get them over the colic, but the laminitis unfortunately tends to be a more long-term problem,” Bozorgmanesh said.
It's hard to say with certainty how many horses with epiploic foramen entrapment recover successfully, though a 2001 study published in the journal Veterinary Quarterly found the survival rate to discharge to be 50 percent for horses with strangulating obstructions of the small intestine.
One thing Bozorgmanesh can say for sure: Ben's Cat's colic also had nothing to do with the length of his race career. Unfortunately, epiploic foramen entrapments can impact horses of various fitness levels in all manner of jobs, both racing and retired horses.
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