I have read that owners of chronically ill pets have higher levels of "caregiver burden", stress and anxiety. Indeed, the pet's eventual death is often an emotionally wrenching experience that can affect the owner's emotional and physical health. Their grief may be as long and severe as when a significant person in their life dies.

This came home to me when I saw a patient who was profoundly depressed following the death of her pet dog. She had been given it by a friend as a puppy. On the first day of bringing it home, the puppy slept on her bed, and continued to do so every night despite the initial disapproval of her parents.