A thought from Doctrine and Covenants 77–80.
It might seem like a minor detail, but there’s something truly wonderful revealed in Doctrine and Covenants 77: animals have spirits too!
The “beasts” and “creeping things” and “fowls of the air” were created spiritually first. Their spirit bodies resemble their physical bodies. And they, like us, will enjoy “eternal felicity”—happiness and joy in their resurrected bodies—if they do what is required of them (see Doctrine and Covenants 77:2–3).
Now, what the Lord requires of animals, we don’t exactly know. But we know Heavenly Father created them, gave us responsibility over them, and wants us to treat them kindly.