Lethargy, increased vocalizing, appetite changes, hiding and loss of interest in play can indicate grief.
Cats may search for their missing companion. They don't understand the permanence of death.
Cats may act aggressively toward other pets as they struggle with the upheaval in their social group.
Give extra affection and play to help lift your cat's mood after a loss. Spend more quality time together.
Understand depression and behavior changes can last weeks or months. Let your cat mourn naturally.
Maintain your cat's regular feeding, play and sleep routines to provide stability.
In time, adopting another pet may ease loneliness. But don't rush into replacement.