As an animal lover, I would like to think that animals go to heaven and I can see all my childhood doggies in heaven. But we have to be realistic and approach the subject rationally. If gorillas and dogs are in heaven, then what about fish and insects and ants? What about germs? What about non-living things? Did Wilson from castaway go to heaven?
Too many people treat heaven like a place where they get to meet up again with all their lost loved ones. To relive the past that they could never let go of. But sadly, it can't be like that. The love we feel in heaven; the real, substantial love known as "agape", will be very different from the stunted, exclusive neurotic "love" we feel down here on earth, which is just a biproduct of chemical reactions and biological drives. When we get to heaven, we have to give up those earthly relations. Chtist himself said that we have to love him more than our family and friends.
How can we enjoy heaven knowing we can't have our pets? How can we enjoy heaven knowing that a select few of our loved ones are in hell? It is because we abandon those illusionary relationships when we see the face of God. When we die, we are born to eternal life, but we still die. Death involves loss, and losing things to the sands of time. At the end of everything, it is just you and God. No one else.
Christ preached the good news, but there is a dark, grim reality contained in that good news that we can't just ignore or delude ourselves out of. We need to embrace death and finality to be a good Christian. Not to pretend that it is all sunshine and rainbows