There's a beautiful peom that I like to refer to when it comes to a lost furry friend. It's called the Rainbow bridge. It's very beautiful and touching; and I get really emotional when I read it.
Although the poem was written very recently, and not necessarily part of any particular religious beliefs, I think the poem reflects a poetic way of what happens when a pet is reunited with a loved one after death. Here's a link to it:
http://www.petloss.com/poems/maingrp/rainbowb.htm
Part of me thinks of the rainbow bridge, perhaps as a branch of Heaven that's specially reserved for animals. The animals I loved and lost, are now healthy and happy, sitting at God's side or on his lap, and enjoying peace and tranquility.
I think that stray, feral and wild animals as well as animals in zoos and circuses etc. deserve to go to heaven as well. All animals in fact. After all, alley cats have a very hard and short life. It'd be nice if there was a paradise they could come to where there's no more fear of getting chased by dogs or harmed by people. Maybe in heaven they wouldn't be afraid of people, because they'd know God's presence was there.
And on another note...a friend of mine and I got into an interesting conversation. Would cat heaven be mouse hell?

I mean...I would think in cat heaven there'd be tons of mice to catch and play with. But it wouldn't be heaven for mice now would it?