Here’s a quick way to diagnose a displaced abomasum in fresh cows: while you’re taking the cow’s temperature, reach around to her left side and push your fist into the “triangle” in the middle of her flank (as shown in photo). At least one rumen contraction should push back on your fist within 30 seconds. If not, the cow needs to be checked for a displaced abomasum, says Sheila McGuirk, veterinarian at the University of Wisconsin’s School of Veterinary Medicine.