The RAU Animal Immobilizer delivers a low-level electrical pulse through a rectal probe that is designed to temporarily and immediately immobilize a chute-held animal so that it can be worked (e.g., branding, dehorning, castrating, hoof trimming, inoculating, drenching) without the need for clamps, clips, or other mechanical restraints. The pulse stimulates the nervous system's response to motor muscle constriction, which immobilizes the animal for the duration of the pulse without affecting its breathing, heart, or other vital organs. Once the probe is removed, the animal reportedly returns to normal instantly.