With a newborn foal, you observe a checklist of progressive behaviors: Regular breaths, ears up, standing, and nursing. Once the foal has survived these adjustments to life after birth, you’re tempted to sigh with relief (and go back to bed!).

But to thrive, the foal’s digestive system must function in both ingestion and excretion. A newborn can appear normal, yet in his first hours he could suffer a serious problem. The foal could be a candidate for impaction colic due to retained meconium.

The foal, like other mammals, is born with meconium waste in his bowel. The Oxford English Dictionary defines this as a “dark excrementitious substance.” These feces develop in the intestinal tract during the foal’s fetal period, produced from cell debris and other wastes ingested during gestation. At birth, the gastrointestinal system is ready to function, and the first bowel movement begins the discharge of the material through the colon and out through the rectum.

In a recent article, Noah Cohen, VMD, PhD, Diplomate ACVIM, and M. Keith Chaffin, DVM, of Texas A&M University, noted, “An onset of clinical signs at or just after birth indicates the possibility of a congenital problem. Colic caused by retained meconium must be considered because of the high prevalence of the condition.”

The foal’s digestive tract must begin functioning immediately after birth. The nursing foal will ingest from 20-25% of his weight daily in mare’s milk. To survive, his system must function like an adult’s–gastrointestinal motility (spontaneous movement) processes nutrients and eliminates waste. You can observe this function by the amount of waste the foal evacuates in his first hours.

The dam’s first milk, colostrum, produces a laxative effect that helps purge the foal’s system. Shortly after he begins nursing, the foal should pass the black feces of meconium.