I am Catholic and well the teaching of the church is somewhat silent on whether animals will definitly be in heaven...I like to believe that is because it is something that cannot be known to us here on earth, but I also like to have faith that God is fair and would want us to have our precious pups in heaven...
Pope John Paul II taught love for animals, and I since is the only Pope I have known in my lifetime I will listen to him...
...In 1990, His Holiness traveled to Assisi the birthplace of St. Francis (the patron Saint of animals) and spoke of the saint's love for animals. He declared, "We, too, are called to a similar attitude." He proclaimed that "the animals possess a soul and men must love and feel solidarity with our smaller brethren." He went on to say that all animals are "fruit of the creative action of the Holy Spirit and merit respect" and that they are "as near to God as men are," and reminded people that all living beings, including animals, came into being because of the "breath" of God. Animals possess the divine spark of life--the living quality that is the soul--and they are not inferior beings, as factory farmers, fur farmers, puppy millers etc, and would have us believe.
I believe in the Pope's teaching because well he is the elder of my church...But even if you are not Catholic but are some denomination of Christian there is some scripture that should make you hope your animals will go to heaven...For example:
Isaiah 11:6-11: “the wolf will live with the lamb, the leopard will lie down with the goat, the calf and the lion and the yearling together, and the lion will eat straw like the ox . . . They will neither harm nor destroy on all My holy mountain for the earth will be full of the knowledge of the Lord . . .” (Isaiah 65: 25).
PSALM 36:6 "Your righteousness is like the mighty mountains, your judgments are like the great deep; you save humans and animals alike"