Companion animals including dogs, cats, and horses show behavioral and physiological responses to the death of bonded companions that indicate genuine grief experiences.
Animal grief challenges the historical assumption that non-human animals lack the cognitive and emotional complexity for bereavement. The behavioral evidence — searching for absent companions, reduced interest in food and play, altered sleep patterns, and prolonged behavioral change — parallels grief responses in humans closely enough to warrant the same interpretation: these are animals experiencing something akin to loss. Recognizing animal grief has practical welfare implications: bereaved pets need patience, routine maintenance, and in some cases veterinary support for anxiety or depression. Well-meaning owners sometimes acquire new companions quickly to replace the lost animal, but this can impose additional social stress on a grieving animal before it has adjusted to the existing loss. Grief-informed companion animal care treats the surviving animal as a mourning individual, not a behaviorally malfunctioning one.