There are some comforting verses in the Bible that show God doesn't forget animals -
"God.. in whose hand is the soul of every living thing" (Job12:10 KJV)
Jesus said:-"God won't forget the death of a sparrow" (Matt 10:29)
To comfort a child (and ourselves) when grieving for a dead pet, it might be a good idea to tell them that even though we regard pets as belonging to us, they really belong to God, its as if he lets us look after them for a little while and then calls them back to him because he misses them so much..
God said - "Every animal of the forest is
mine,and the cattle on a thousand hills.I know every bird in the mountains,and the creatures of the field are
mine,for the world is
mine,and all that is in it" (Psalm 50 10-12)
