A foal is rolling and straining to defecate. What condition is most likely causing this?

When a foal is rolling and straining to defecate, meconium impaction is the most likely cause of these symptoms. Meconium is the first feces that a neonate produces, and in foals, it can sometimes become impacted in the intestines, particularly if the foal has not passed stool within the first 24 hours of life. The impaction leads to abdominal discomfort, causing the foal to roll and strain in an attempt to relieve itself.

Meconium impaction is a common condition in foals and generally presents with signs of colic, including rolling, pawing, and straining to defecate. It is important to differentiate this from other conditions such as colitis, which may cause diarrhea rather than straining to defecate, intestinal torsion, which typically presents with acute severe colic and possible shock signs, and coccidiosis, which is usually associated with diarrhea and may not present with significant straining to defecate. Therefore, the signs of rolling and straining to defecate in a foal align closely with meconium impaction.