Dogs, cats, horses, and other companion animals show behavioural and physiological responses to the loss of bonded companions that parallel human grief, with important welfare implications.
Animal grief is not merely anthropomorphic projection — the physiological and behavioural evidence that companion animals experience distress after losing a bonded partner is substantial. The welfare response to companion loss should include maintaining routine to provide stability, increased gentle human contact, and patience with behavioural changes including reduced appetite or altered sleeping. Forcing rapid social reinstatement with an unfamiliar replacement animal often adds conflict stress. Veterinary guidance may be warranted if grief responses are severe or prolonged. Recognising companion animals as social beings who mourn is part of giving them the respect their emotional complexity deserves.