The AERC Veterinary Committee has become increasingly aware of the number of post-ride colics, some with poor outcomes. This article is intended to remind endurance riders about the potential for post-ride colic, signs of post-ride colic and the benefits of early treatment for these colics.

In the March and April (2006) issues of Endurance News, there was a very good two-part article on colic written by Vet Committee members Jim Bryant, DVM, and Ann Stuart, DVM. These articles additionally provide good information on the subject and should be reviewed (they are available online at www.aerc.org/ENMar06Vet.asp and www.aerc.org/ENApr06Vet.asp).

Signs of post-ride colic

You have finished your ride and your horse has passed the post-ride completion veterinary check with all parameters looking normal. The vet performing the exam says your horse looks fine and you head back to your camp for rest and food for yourself.

This is the time to be vigilant in watching your horse's behavior. Signs to watch for that are cause for concern can be subtle. A decrease in the horse's normal appetite or just a tired or uncomfortable look in the horse's eye can be signs of an impending metabolic crisis. More obvious signs of colic are lying down and getting up repeatedly, looking back at the abdomen or pawing.

The term colic is a general term for abdominal pain. Any of these signs are reason to bring your horse back to the ride veterinarian for re-examination. These signs may show up very subtly shortly after the ride but can progress hours later to a severely painful horse.

Ileus: a common culprit

A common cause of post-ride colic in endurance horses is a condition know as ileus. Ileus means that the normal intestinal activity and motility has slowed or stopped. Intestinal activity commonly slows after physical exercise because the blood flow that would normally supply the intestines has been diverted to exercising muscles.

Electrolyte losses through sweating can also contribute to ileus, as electrolytes are involved in the normal signaling of impulses from the nervous system to the smooth muscle of the intestines. The normal intestines of horses are in constant motion, moving fluid and ingesta further down the digestive tract. With ileus, all of this motility comes to a standstill and fluid and ingesta back up in the digestive tract into the stomach. The stomach rapidly reaches full capacity and since horses cannot vomit, the stomach can rupture. Gastric (stomach) rupture is an extremely painful and always fatal condition in the horse.

Ileus is best treated with early, aggressive and abundant fluid therapy and nasogastric tube placement to relieve the fluid and ingesta from the horse's stomach. The nasogastric tube will often need to either be left in place or placed repeatedly. Fluid therapy helps to correct electrolyte imbalances and increases blood flow to the intestines, which will assist the horse in regaining normal intestinal motility.

The key factor in successfully treating ileus is early recognition and early treatment. Waiting until the horse has progressed to the very painful stage is often too late for a successful outcome.

Surgical options

Some horses with post-ride colic may require surgical exploration for determination of the cause and resolution. Not all colics can be successfully treated medically and early referral to a practice with surgical capabilities may be critical.

Prevention strategies

There are things you as a rider can do during the ride to help prevent post-ride colic:

-- Properly rate your horse through the entire ride. Do not allow your horse to travel faster at any one point during the ride than he is conditioned to travel, no matter how short the distance.

-- Give your horse small, frequent meal breaks. If there is grass available for grazing along the trail, take advantage of this. Frequent intake of small amounts of forage will help maintain normal gut motility.

-- Pay attention to your horse's water and electrolyte intake.

After the ride, offer your horse forage, preferably wet, and pay attention to the subtle signs that may indicate an impending colic, such as depression and a decrease in appetite. By seeking early treatment, riders and ride vets together can improve the outcome for the horses with post-ride colic.