We've all dealt with the loss of a pet. Nothing hurts more. Here are a few comforting books written by people who have experienced the same thing.
Healing the Pain of Pet Loss: Letters in Memoriam
The Loss of a Pet, 3rd Edition
Grieving the Death of a Pet
Blessing the Bridge: What Animals Teach Us About Death, Dying...
Three Cats, Two Dogs: One Journey Through Multiple Pet Loss
Animals and the Afterlife