“In recent years, there has been a growing tendency toward delayed referral of colic cases,” begins David Freeman, MVB, PhD, DACVS, of the University of Florida. Freeman presented his information on equine colic surgery referral at the 2022 AAEP Convention.
He said that with delay in referral comes an increase in negative outcomes.
Freeman attributed this delay to several owner and trainer misconceptions about colic surgery. They think it is rarely successful; the horses are never the same; or a sick horse can’t handle the travel, surgery or anesthesia. In other cases, an owner might exclaim, “Surgery is not an option.” This could be, in part, due to cost as a major issue. However, it is not uncommon for an owner’s sentiment to change as the horse’s progression worsens. However, by then too much time could have elapsed and the window of “golden opportunity” for colic surgery has passed.
Freeman stressed that early referral is important for short-term and long-term equine survival and avoidance of post-operative ileus, particularly after small intestinal surgery. He added that horses with a shorter duration of colic are significantly less in need of intestinal resection and anastomosis than those with longer colic durations.
That said, it is sometimes difficult to determine how long a horse has had colic pain. That might occur since an owner might come out in the morning to feed, only to find the horse in distress for an unknown period of time.
It is important to get a horse to surgery before the bowel experiences irreversible changes, he stated. The advantages of not having a resection are many. These include improved survival rate, decreased complication rates, decreased cost and a more simplified surgery with less time of the horse on the table under anesthesia.
Freeman said cases often end up going to delayed surgery or are euthanized when an owner declines surgery after it is recommended, but approved continuation of medical treatment.
Colic Myth Busting
Freeman busted a widely held horse owner myth by saying that with today’s surgical advances, there is a good prognosis for a horse’s return to use and performance following colic surgery.
Another myth he busted has to do with older-aged horses not being able to withstand colic surgery. He said there is no reason to be pessimistic about geriatric horses undergoing colic surgery. They have comparable survival rates to young horses.
For a horse with co-morbidities, a frank discussion enables the owner to factor those issues into the colic surgery decision.
The most common lesion in horses older than 20 years is strangulation of the small intestine. This occurs in 60% of cases. Horses aged 4-15 years have small intestinal strangulation as the least common lesion (at only 19% of cases). He cautioned that if a colicky horse is 15 years or older, consider the cause as a strangulating lipoma until proven otherwise.
Freeman pointed out that pain does not always correlate with disease severity. This is because pain might be severe initially. It might then diminish due to endotoxemic stupor, analgesics administered, individual pain tolerance, old age, and breed predilection. Specific breeds are more stoic, such as Tennessee Walking horses, small breeds and draft breeds.
The horse that is found with self-inflicted trauma, especially around the head, has likely experienced hours of advanced and severe disease.
Beyond Obvious Lesions
One important feature to recognize is that a horse with a small intestinal strangulation might have a palpable colon impaction on rectal exam. Freeman said that the colon lesion is misleading and often secondary to dehydration. Efforts should be made to evaluate the entire bowel, not just the obvious impaction lesion.
To help an owner decide whether to take a horse to colic surgery, Freeman recommended localized abdominal sonography on the left side. Take caution to recognize that “finding nothing means nothing.”
There are also limitations to an abdominocentesis. Gross appearance is not always helpful. For example, the sample might be normal in appearance and cell count despite intestinal rupture. Large colon volvulus and other surgical diseases often have normal-looking peritoneal fluid, at least initially. Repeated lactate concentrations from peritoneal fluid are helpful.
I.V. or not to I.V.
Should a veterinarian give intravenous fluids before referral for small intestinal strangulation? Freeman said it is best just to load and ship the horse as soon as possible to the surgery center. Delays in getting the horse to surgery result in progressive worsening of the lesion.
In addition, he noted that large volumes of intravenous fluid can be damaging to intestinal micro-circulation. It can also impair smooth muscle function. Intravenous fluids also add expense to the client.
The conundrum is what to do with a horse faced with a long haul. In many states, it is illegal to ride in the horse trailer. So, administering IV fluids on the road is not plausible or safe. He said that if the horse truly needs IV fluids, it is even more important to refer the horse promptly.
Take-Home Message About Equine Colic Surgery Referral
In summary, Freeman urged equine practitioners to educate owners and caretakers about colic surgery well in advance of a necessary situation. He said veterinarians also should discuss the possibility of acquiring equine surgical insurance. Teamwork between the owner, the referring DVM and the surgeon helps to resolve misconceptions about cost estimate and prognosis of surgery, as well as avoiding duplication of procedures.