There is a popular and widespread assumption that before Adam sinned there was no such thing as death in the world. In other words, the whole animal creation was immortal.
The basis for this weird assumption seems to be the statements in Rom 5 and 1 Corinthians 15 that death entered the world through the sin of Adam. But the context is quite clear that the apostle is talking about human death rather than the death of animals or plants. Rom 5:12

Therefore, just as through one man sin entered the world, and death through sin, and thus death spread to all men, because all sinned (NKJV)

But if there was no such thing as death then how could Adam have understood God’s warning that if he sinned he would surely die?

I believe the idea that the death or pain of animals is an evil is silly and anthropomorphic. I suspect it is a result of most Christian writers and preachers being town dwellers and rather squeamish about the realities of natural life. Every countryman knows very well that death and procreation are essential to the life of the countryside. Predators survive and prey species are kept fit by the process of hunting and killing.

Some of God’s most magnificent creations are meat eaters. The lion is an image of Christ in his Majesty and would not be the lion if it were a vegetarian. It would need to change its teeth, claws, digestive system, metabolism and behaviour. In other words, become something like a wildebeest or buffalo.

The modern science of ecology reveals what has been known intuitively from millennia past by country dwellers. That God has created an intricate web of existence encompassing the animal and plant kingdoms in a pattern of interdependence in which death and reproduction play roles which are absolutely essential.

When God created the world he created it to be self-sustaining so that he could rest from creation on the seventh day. I do not deny that, in some profound way, all things are still sustained by Him but they are sustained in the pattern of interdependence which Has has created and which He oversees still.

But what of the world to come? What of Isaiah’s prophecy in Isa 65:24-25:

24 “It shall come to pass
That before they call, I will answer;
And while they are still speaking, I will hear.
25 The wolf and the lamb shall feed together,
The lion shall eat straw like the ox,
And dust shall be the serpent’s food.
They shall not hurt nor destroy in all My holy mountain,”
Says the LORD.(NKJV)

My dear wooden-headed, cloth-eared Christian brother! Have you no poetry in your soul at all? Can you not see that it is people God is speaking about here? Go read 1 Cor 9:9-10 to see what God really cares about.

God will answer the urgent prayers of His people by bringing peace to the Earth. I have never prayed to see a lion eating straw but pray often for violence and destruction to be suppressed. What about you?

We humans have the dignity of being animals made in the image of God. We only bear that image by being alive and it is for this reason that human death is a tragedy and for this reason that the Christian hope is a hope of resurrection to an immortal bodily life. Jesus shared our death so that we could share his resurrection. Jesus died for you. He did not die for your dog.