Yes, but at the moment, I am unable to find my research. Right off hand, I know that the New Testament says that "all creation groans, waiting for the return of the Children of God" and that in Heaven, the lamb will sit down and feed next to the lion; also, Jesus mentions that ,"outside the gates of Heaven, where the dogs are" [IMO, the dogs are faithfully guarding the gates of Heaven, keeping out the bad spirits]. Besides, the Bible is the Living Word, and speaks to each of us individually, and constantly; God speaks to each one of us according to our own heart. So, if it has been given to your heart that animals are in Heaven, (and to so many others), then who are we to argue with God?
IMO, many people don't like the idea that we have to "earn" the right to go to Heaven - i.e. we are given a conscience and must make A CONSCIOUS decision to obey God and enter the Kingdom; if He had wanted animals to do the same, they'd get the same liberties that we enjoy, such as choosing our language; how we want to live, work, whether or not to be vegetarian, etc.