In a hog barn in rural Iowa, veterinarian Paul Thomas’s approach sends pigs scurrying. He watches for unusual behavior. As he walks the length of the barn, Thomas notices one of the two-month-old hogs nestled against the railing at the edge of its pen and reaches over to gently pet the pig’s back. The pig shakes its head and drowsily gets up.
“He’s just sleepy,” Thomas says, and by the time he’s spoken the words, the pig has trotted off to join its pen-mates.
In the next room, Thomas hears something different.