Compare with Isaiah 65. Here it talks about young children. In 65 it talks about birth and death. That won't be happening in heaven. I think these verses are talking about the millenium, not heaven.
Of course it is, and the millennial reign is a type of heaven on earth.
I also mentioned that when God created the animals of the earth He saw it was good, so what was good for earth may be also be good in heaven.
But most importantly, we can trust Him to provide for our needs, so if we might have the same need for animal companions in heaven as we do on the earth, that need will be provided for. If we don't, from being otherwise fulfilled, it won't matter and we will not miss or be aware of the absence. When we come to that point of trust in Him, nothing else matters.
