Where do animals go when they die?

Where do animals go when their journeys here on earth in their bodies are done? Go down? Up? If down or up, where to? During the fall season leaves are falling to the ground, only to see trees coming back with brand new ones in the spring. Yes, the life of a believer is hidden in the Lord, so as He appears we also will appear. But what about animals, especially your favorate pets A friend of mine had the anser, that is, somewhere in Revelation 5 (where all creatures sing; what does 'all' mean, and why do they sing?), Romans 8:20-22, etc. and so forth. He lost his dog Mushi. I lost my pet Sammy (he used to enjoy the morning sunlight), so we comforted each other saying, "Look, when Jesus appears again, even cats and dogs will rise and get along saying, 'Hi, dog' or 'Hi, sammy'!" Isaiah 11.