Growing up, I had a lot of pets for friends- fishes, dogs, cats, and turtles just to name a few. And as each one passed, I always had one question in mind- "Will I ever see Shadow, Tiger, Bridget, Spike, Buddy, David or Goliath ever again?"
You've probably asked that question before or maybe you have a five or six year old inquiring melancholically as you flush a goldfish down the toilet. It's not a big theological question, but it's a legitimate one nonetheless.
The Bible is never explicit about whether animals will co-exist with us in heaven. Some scriptures have made mention of the presence of animals in heaven. Here are two for instance:
Isaiah 11:6 "The wolf shall dwell with the lamb, and the leopard shall lie down with the young goat, and the calf and the lion and the fattened calf together; and a little child shall lead them."
Revelations 19:11 "Then I saw heaven opened, and behold, a white horse! The one sitting on it is called Faithful and True, and in righteousness he judges and makes war."
However, these scriptures make mention of animals most likely as allegorical symbols and not as actual accounts of animals in heaven. The most important consideration is whether animals have a spirit or not. We know for a fact that only spirits enter the kingdom and our bodies are left behind with everything natural.