Artiodactyls (e.g., cows) regurgitate food that has been swallowed, chew it again, and then reswallow
The presence of coarse fiber particles in the rumen stimulates rumination, during which particles are regurgitated, remasticated and reswallowed
. Particles over time become smaller due to mechanical breakdown and denser due to digestion of lighter cell-wall components.
The food is then ejected from the mouth or reswallowed
." The purpose of this report is to describe two cases of rumination that were benign, self-limited, and different from rumination previously described in the medical literature.