It is important to note that everything that God created has some type of existence forever. Nothing that was the work of God just vanishes into nothingness. But the manner in which it continues to exist for eternity varies upon its type of soul, the purpose for which it was created, and also what it accomplished with its life in this world. Obviously animals are different than humans, and although they have a soul called a "nefesh", they do not have "higher" levels of souls, such as a "neshama".
So I do not think there is an "Animal Heaven" in the same sense that there is a spiritual “Gan Eden” for the souls of humans.
