Animals show clear behavioral and physiological responses to the loss of bonded companions, and supporting grieving pets through the transition reduces their suffering.
Companion animal grief is a welfare reality that many owners underestimate, partly because grief responses in animals are less recognizable than in humans and partly because the concept of animal grief remains culturally contested despite strong scientific evidence. Dogs in homes where a canine companion has died show significantly elevated glucocorticoid levels and behavioral disruption measurable for weeks. Cats may search extensively for missing companions and show appetite reduction. The welfare-appropriate response includes maintaining routine to provide stability, offering increased human interaction, and monitoring closely for signs of depression including complete appetite loss. Species-specific considerations matter: rabbits and horses should not be left alone after companion death if at all possible, as social isolation in these species causes acute distress. Introducing a new companion should be timed based on the individual animal s recovery rather than the human s readiness.