How do you explain why God allowed countless animals to suffer before humans even existed, before mankinds rulership began? At that point, surely, it was all under God's rule?
What makes you think there was suffering?
Things were good when God first created the animals:
And God went on to say: "Let the earth put forth living souls according to their kinds, domestic animal and moving animal and wild beast of the earth according to its kind." And it came to be so. 25 And God proceeded to make the wild beast of the earth according to its kind and the domestic animal according to its kind and every moving animal of the ground according to its kind. And God got to see that [it was] good.
"If you see suffering it is because of the futility of a rulership that has become seperated from God."
The whole creation is suffering under the futility of allowing the most intelligent men to decide what they think is the right thing to do.
God is "allowing" this to happen so you can measure its value.
You can see the futility!
You can look around the world and see for yourself the cumulative value of all those decisions that the most intelligent men are making.
and yes, those decisions greatly effect the animals.
Eventually those men will be replaced by; "the sons of God".
Consequently I reckon that the sufferings of the present season do not amount to anything in comparison with the glory that is going to be revealed in us. 19 For the eager expectation of the creation is waiting for the revealing of the sons of God. 20 For the creation was subjected to futility, not by its own will but through him that subjected it, on the basis of hope 21 that the creation itself also will be set free from enslavement to corruption and have the glorious freedom of the children of God. 22 For we know that all creation keeps on groaning together and being in pain together until now.