The Lord has blessed this planet with a vast array of animals....many of which have been domesticated and become pets. However, all creation belongs to the Lord and our pets are His.....So they, like all animals should be respected, loved and cared for. Animals may be used for mankind (meat, leather, toil etc) but never cruelly abused,
It is natural to grieve the loss of a pet.
And as Christians we have the Lord as our perfect comfort in times of sorrow.
Think of the sparrows.... Are not two sparrows sold for a penny? And not one of them will fall to the ground apart from your Father. Matthew 10:29