Microchipping companion animals dramatically improves the probability of reunification after loss — a welfare intervention that prevents the suffering of extended stray periods, shelter housing, and failure to return home.
A companion animal lost without identification faces a welfare trajectory that includes disorientation, exposure to traffic and predators, hunger and thirst while searching for home, and eventual capture leading to shelter housing with its attendant stresses. Each day of this trajectory involves welfare costs that microchipping can prevent by enabling prompt reunion. The welfare benefit of microchipping is asymmetric — the procedure causes brief, minimal discomfort while preventing potentially extended periods of welfare-impacting stray experience. Cats are particularly underserved by identification systems because collar loss is common — microchipping provides permanent identification that cannot be lost. Up-to-date database registration, often neglected when people move, is the critical link between chip and reunion.