I was forced to attend Christian Schooling/Indoctrination from the time I was in Kindergarten, right up to ninth grade, when I finally refused to go any further, so took measures to guarantee they wouldn't let me (basically, I beat the shit out of one brat girl who refused to stop harassing and bullying another, this having gone on for years w/o the psychotic penguins/anyone putting a stop to it.).My beliefs are complicated. I believe the physical and spiritual realms exist and I believed that even before I was a Christian. I believe that humans have a body, non-physical mind and a spirit. What I would call a soul is that non-physical mind, which I believe every thinking being is granted by God, be they human, animal or insect. The spirit is something unique to humans and it's through the spirit that humans can know God in a way that no animal can.
Now I stress that these are my beliefs and there are many Christians who would disagree with me on whether souls and spirits are fundamentally different or if they're one and the same and that's fine. The Bible could be interpreted through either viewpoint and I believe it doesn't affect the core teachings of sin, salvation and the like. If you disagree and want to debate me about these things, please do so in PM and don't disrupt this thread!
Now, back to the topic: as how this relates to the afterlife. The Bible is pretty clear that there will be animals on Earth after it's been restored to the state of Paradise. It doesn't say if God will resurrect previously deceased animals to populate Paradise but I don't see why He wouldn't so I choose to believe that He would because I believe He loves animals too and He wants us to be happy.
As for whether or not they're awake and alive in Heaven, I personally don't believe that because I believe that Heaven is exclusively the realm for spirits, and it's there that we can have spiritual fellowship with God no matter if we're alive or dead. I believe that we will be reunited with our pets when we're reunited with our bodies during the resurrection at the end of days.
I remember well getting into a near physical fight with one penguin about the topic of Souls, and how she insisted animals had none. My take on it, and what I asked and refused to back-down on was this- If 'God' made all things, including animals, before 'Man', then every living thing has been touched by God, and so has a part of Divinity in their existence. They have a Soul, too.
That was an epic event, and only one of many in my early years. I won't bother with the rest because it's not on topic with the O.P..
As someone who grew up on a working ranch (sheeps, cattle, horses, pigs, chickens/fowl, so on), and as an adult who hunts and is heavily invested in 'Animism' as a way of Faith, I genuinely respect every living thing and try to honor those who help me live. I never take an animal's life w/o offering a prayer of thanks and gratitude to it, and 'God' in the ways I think of it.
Now, if there's a 'Heaven', and if I happen to find myself there after this body dies, and my beloved critter friends aren't also there waiting to reunite with me? I'm leaving!