There is no specific Biblical proof that animals have a soul or an afterlife. Animals, though, are part of God’s perfect and wonderful creation and as such, they bring glory to Him. Heaven is likely to contain all of the best of God’s handiwork, and more. It may be that believers will be privileged to enjoy their beloved pets as well as all of the other types of animals that we now have to view from behind bars at the zoo.
I can think of many people, myself included, who have never been able to get close to animals because of severe allergies. We know that Heaven will completely eradicate that illness. So, I am open to the idea that animals will be in Heaven. But, even if they aren’t, I still want to be!
“And Elisha prayed, and said, Lord, I pray thee, open his eyes, that he may see. And the Lord opened the eyes of the young man; and he saw: and, behold, the mountain was full of horses and chariots of fire round about Elisha” (2 Kings 6:17).
“And I saw heaven opened, and behold a white horse; and he that sat upon him was called Faithful and True, and in righteousness he doth judge and make war” (Rev 19:11).
“And the armies which were in heaven followed him upon white horses, clothed in fine linen, white and clean” (Rev 19:14).