I believe the answer to God's concern for animals in the final verses of Jonah is quite simple - God is actually concerned for animals!
There is a simple element of police training in many western countries - wherever cruelty and abuse of animals is seen, there will also be cruelty and abuse to humans in the weakest part of society and vis-versa. That is, cruelty to humans and animals go hand-in-hand. This can be seen here:
- Prov 12:10, “A righteous man has regard for the life of his animal, but even the compassion of the wicked is cruel.”
- Hab 2:17, The violence you have done to Lebanon will overwhelm you, and your destruction of animals will terrify you. For you have shed human blood; you have destroyed lands and cities and everyone in them.
- Jonah 4:11 – God expresses the desire to save Nineveh because of the people and the animals!
It is apparent that Nineveh's appalling moral condition was having a devastating result on animal welfare that the LORD addressed here as well. These are part of more general pattern in Scripture that requires people to be be kind to animals:
- Prov 27:23, “Know well the condition of your flocks, and pay attention to your herds.”
- Deut 25:4, “You shall not muzzle the ox while he is threshing.”
- Luke 14:5, “And He said to them, ‘Which one of you will have a son or an ox fall into a well, and will not immediately pull him out on a Sabbath day?’”
- Ex 23:5, “If you see the donkey of one who hates you lying helpless under its load, you shall refrain from leaving it to him, you shall surely release it with him.”
- Genesis 33:13-14, “Jacob said to him, ‘Sir, you know that the children are frail and that I have to take care of the flocks and cattle that are nursing their young. If they’re driven too hard for even one day, all the flocks will die. Go ahead of me, sir. I will slowly and gently guide the herds that are in front of me at their pace and at the children’s pace’”.
- Isaiah 11:6-9, “A wolf will reside with a lamb, and a leopard will lie down with a young goat; an ox and a young lion will graze together, as a small child leads them along. A cow and a bear will graze together, their young will lie down together. A lion, like an ox, will eat straw. A baby will play over the hole of a snake; over the nest of a serpent an infant will put his hand. They will no longer injure or destroy on my entire royal mountain.”
Benson observes the following about Jonah 4:11 -
And also much cattle — Besides men, women, and children in Nineveh,
there are many other of my creatures that are not sinful, and my
tender mercies are, and shall be, over all my works. If thou wouldest
be their destroyer, yet I will be their saviour. Go, Jonah, rest
thyself content, and be thankful that the goodness which spared
Nineveh hath spared thee, in this thy inexcusable frowardness,
peevishness, and impatience. I will be to repenting Nineveh what I am
to thee, a God gracious and merciful, slow to anger and of great
kindness, and I will turn from the evil which thou and they deserve.
The Jamieson-Fausset-Brown Bible Commentary reaches a similar conclusion -
much cattle—God cares even for the brute creatures, of which man takes
little account. These in wonderful powers and in utility are far above
the shrub which Jonah is so concerned about. Yet Jonah is reckless as
to their destruction and that of innocent children. The abruptness of
the close of the book is more strikingly suggestive than if the
thought had been followed out in detail.