Which test can help rule out meconium impaction in a foal?

• A. Rectal
• B. Blood glucose
• C. Thoracic radiographs
• D. Endoscopy

Answer: (A)

In a newborn foal with suspected meconium impaction, a rectal examination is the most informative test because it allows direct palpation of the colon to feel the thick, inspissated meconium mass. You can often detect a firm fecal ball or a distended segment of colon, and this finding helps confirm the diagnosis and guide immediate management, such as manual expression or targeted enemas. If this exam doesn’t reveal an impaction, other causes of colic may be considered and further evaluation might be needed.

Other tests don’t help for this purpose: blood glucose assesses metabolic status rather than the GI contents; thoracic radiographs evaluate the chest, not the hindgut; endoscopy examines the upper GI tract and cannot reach the colon to assess meconium impaction.