With foaling season rapidly approaching, many people are checking their foaling kits, and preparing for the big delivery. You've got your thermometer, stethoscope, umbilical tape, disinfectant to dip the umbilicus, and lots of towels. The foal is delivered and thankfully, no problems--he's up and nursing in no time. A few hours later, you go back out to check on the new addition and the foal is lying down and not comfortable. He keeps straining and he's stopped nursing.

This scenario is all too familiar for neonatal foals. Passing the meconium is, to me, the second-biggest hurdle a foal must overcome after birth--the first, obviously, is making the transition from the protected life within the uterus to life outside the uterus (breathing, standing, nursing).

Here are some of the most common questions I get asked about meconium:

What is meconium? What do foals look like when they are having trouble passing their meconium? When should I call the veterinarian for help? What can I do to help the foal pass his or her meconium, and how do I know when it is all passed?

If you didn't know the answers to the above questions, we will discuss all of these points, so read on.

What Is Meconium?

Meconium is the first manure produced by a foal, and unlike milk feces, it is hard, dark, and pelleted in nature. The meconium is made up of amniotic fluid and other material the foal swallowed while it was within the uterus. Meconium builds up within the rectum and small colon of foals during gestation and is not expelled until the foal is born.

Passing the meconium often is uncomfortable for foals, as these little pellets seem more like boulders to the foal. Most foals will strain to some extent to pass the meconium. Colts more than fillies tend to have a problem passing the meconium. This phenomenon is believed to be related to the smaller diameter of the colt's narrow pelvis compared to a filly's, which predisposes the colts to developing meconium impactions.

What Do Foals Look Like When They Are Having Trouble Passing Meconium?

Usually, a foal will begin to pass the meconium at a few hours of age. It should be replaced by the softer, yellow milk feces by no later than 24 hours of age. Some foals will not strain at all and pass their meconium with no problem; others will strain and strain and might even show signs of colic.

A foal which is straining to pass the meconium (defecate) will stand with its back arched and tail up in the air. This is a very different posture from a foal straining to urinate--he or she will stand with the back concave (U-shaped). The foal which is having trouble passing the meconium usually will become restless with multiple attempts to defecate. He or she might even progress to full-blown colic (getting up and down frequently, rolling). Eventually (usually within 24 hours), failure to pass the meconium results in the foal's abdomen becoming larger and larger. This abdominal distention is due to buildup of fecal material and gas within the gastrointestinal tract.

Although most foals strain to defecate with a meconium impaction, I have had one foal which never strained, just started colicking at two hours of age and after one enema produced a large pile of meconium. He then jumped up and nursed, and I thought, "well, that was easy." Then, 30 minutes later, the foal began to colic again. Another enema and another large pile of meconium, then back to nursing. This went on several more times until all of the meconium was gone and the foal was happy.

The meconium is all passed when the foal begins to produce soft, yellow-brown feces. If the foal is passing soft manure and begins to show signs of colic and/or is not nursing very much, then the pain can be due to another disorder, such as a ruptured bladder. Your veterinarian should examine the colicky foal to determine the appropriate treatment.

What Can I Do To Help The Foal Pass The Meconium?

To help the foal pass the meconium, a single enema or multiple enemas can be administered to help soften and lubricate the feces and/or gastrointestinal tract to make passing the meconium easier. Refractory cases often are administered mineral oil or even intravenous fluids by a veterinarian to help soften the feces. Many large breeding farms routinely give a warm, soapy water enema or a commercial enema, such as a Fleet enema, to every foal born to help ease the passage of meconium and prevent impactions.

An enema can be administered through a soft rubber tube using a dose syringe. This allows for a gravity flow enema and a larger volume of fluid. If you do not have a commercial enema available, my favorite recipe for enemas is several drops of Ivory soap into a quart of warm water; then add one cup of mineral oil (if available) or sterile lubricant. The mineral oil seems to help coat the meconium balls and makes for easier passage.

When Do I Administer An Enema?

The enema should be administered when the foal first is noted as having signs of straining to pass the meconium. Administration before this time might not benefit the foal, and repeated enemas could lead to rectal irritation. Rectal irritation on its own results in straining, which looks identical to straining for meconium impactions--see, the vicious circle?

If several enemas have to be given to help the foal pass the meconium, topical medication such as Preparation H can help soothe the inflamed tissue and decrease the desire to strain.

How Do I Administer An Enema?

Enema administration is a potentially harmful procedure if performed incorrectly and should be performed only in a professional manner. The foal must be properly restrained or risk of perforation of the delicate rectum can be the horrible result. A rectal tear can mean a fatal peritonitis (infection of the abdomen), or even just severe inflammation/infection around the rectum, which could lead to inability of the foal to defecate.

Furthermore, the temperature of the fluid being administered must be checked very carefully, so as not to scald the foal's rectum. The temperature should be warm, but not uncomfortable on your hand. The foal should be restrained in a standing position. Use lots of lubricant, such as KY Jelly. Insert the enema device gently (either plastic bottle or rubber tube), then either squeeze the bottle or begin pouring the water.

After the enema is administered, leave the foal to pass the meconium. If the foal does not produce any meconium, or produces meconium but resumes straining after 30 minutes or so, it is possible there is more meconium to be passed. A second enema can be administered. If this does not produce more meconium or alleviate the signs, then you should call your veterinarian.

Some foals develop large meconium impactions and need further treatment such as mineral oil administered through a nasogastric tube or even intravenous fluids. Remember, if multiple enemas are given, rectal irritation can result, causing persistent straining.

What Else Can Mimic Meconium Impaction?

If the foal does not produce any meconium, and enemas result only in the soapy water coming back out (no fecal material or coloring), then the foal might have a much more serious problem. Atresia coli (lack of a segment of intestine) is a congenital defect that results in foals which cannot defecate. The foals usually have a gastrointestinal tract that ends abruptly in a blind end before it reaches the rectum. The end of the gastrointestinal tract (rectum) usually is normal, just not connected to the front half.

The foal gradually will become more and more bloated, due to the incomplete gastrointestinal tract. He or she occasionally will strain to defecate, but will produce absolutely no fecal material. These foals require surgery as soon as possible to survive.

Surgery can be performed to remove the blind segment and create a patent (open) gastrointestinal tract. A two- or three-day delay in a correct diagnosis and transport to a surgical facility can result in a foal which is too sick to survive. As it distends the gastrointestinal tract, the retained fecal material can lead to shock and peritonitis (infection within the abdomen).

Other atresia syndromes also are possible and include atresia of the anus, which would be noticed as soon as the backside is inspected to take a temperature or administer an enema. Of course, if your foal has not passed any meconium in 12 hours, you need to summon your veterinarian immediately.

What Can The Veterinarian Do?

When summoned to examine your foal (at the 24-hour healthy foal check or sooner if the foal is having problems), your veterinarian will determine if the foal has a meconium impaction or if any of the other mentioned disorders are leading to the abdominal distention and/or straining to defecate. The veterinarian can perform a digital examination (examination of the foal's rectum with a finger) to determine if meconium is lodged in the pelvic inlet. If meconium is felt in the pelvic inlet, then you have your diagnosis. If however, there is no meconium, then there might be other problems that previously were mentioned, such as a ruptured bladder, atresia coli, or a meconium impaction that is farther back in the gastrointestinal tract (large colon).

If further diagnostics are needed, the foal can be taken to an equine hospital, where radiographs (X rays) with or without contrast material to highlight the GI tract can be taken of the abdomen to determine what is causing the straining and/or abdominal distention. Ultrasound alsocan be used as a diagnostic tool in this area.

Your veterinarian also can check to see if the foal has received enough colostrum, which contains antibodies to fight infection. (For more information on the antibodies, or immunoglobulins, that fight infection in foals, see article on foal IgG, article #284.)

If, because of the meconium impaction, the foal has not nursed appropriately and does not have an adequate level of immunoglobulins, then a plasma transfusion can be administered. Your veterinarian will check for other problems, such as broken ribs, cleft palate, and problems with the umbilicus.

Why Meconium Impactions Can Be A Pain For The Owner

The problem with meconium impactions is that they can produce enough pain to keep the foal from nursing properly; the foal then can become dehydrated and might not consume enough colostrum. Meconium impactions are not initially life-threatening. However, they do require prompt treatment as the meconium can act like a cork in the foal's rectum and gas and fluid can accumulate within the intestines, leading to severe bloat.

The bloated intestines not only are extremely uncomfortable for the foal, making nursing out of the question, but also compromise the ability of the foal to breathe normally. Unfortunately, once a foal reaches the severely bloated stage, medical treatment with intravenous fluids and mineral oil will not work fast enough and sometimes a young foal will require surgery.

Surgery For Meconium Impactions

Surgery for foals with large refractory meconium impactions sometimes is necessary. As stated previously, if the impaction has led to severe gas distention within the gastrointestinal tract (gas builds up in front of the impaction as the impacted feces prevent normal expulsion of gas and milk feces), then there is little/no time to wait for intravenous fluids and mineral oil to soften the impaction so it can be passed on its own. Surgery is performed with the anesthetized foal lying on its back.

An incision is made in the middle of the belly in order to gain access to the impaction. Enemas of warm water are administered by an assistant to help soften the meconium and allow the surgeon to "milk" the impaction out the rectum. The surgery is over once all of the meconium has been removed from the rectum, small colon, and large colon. Surgery in such a young foal, although sometimes necessary, is not without risk, as the surgery and the anesthesia are quite stressful to such a young immune system. Also, the surgical incision and abdomen are sites of potential infection, especially if the foal has not absorbed adequate colostrum.

After your foal is born, remember to monitor his or her progress with passing meconium. If meconium is not being produced and/or the foal is straining, you can administer an enema. However, if one or two enemas produce no meconium, call your veterinarian so that the foal can be examined and proper treatment administered.


Christina S. Cable, DVM. Understanding the Foal. The Horse Health Care Library, Lexington, Ky.

Christine Schweizer, DVM. Understanding the Broodmare. The Horse Health Care Library, Lexington, Ky.

Equine Clinical Neonatology. Koterba, Drummond, and Kosch. Lea & Febiger, Philadelphia, Pa.

About the Author

Christina S. Cable, DVM, Dipl. ACVS

Christina S. Cable, DVM, Dipl. ACVS, owns Early Winter Equine in Lansing, New York. The practice focuses on primary care of mares and foals and performance horse problems.

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