[Poll Pitt]

My answer would be maybe.
There are an infinite number of beings and an infinite number of worlds, the universe is a really big place, as well as other realms.
For any being to become Liberated/Enlightened they must first find the Dharma. Then practice and study/contemplate/meditate on it.
Also there would have to be the fortunate event of a Buddha to present the Dharma.
Our world was fortunate to have this happen.
And we were fortunate to have a precious human birth in which to experience the Dharma.

As to animals my friend, I believe they can understand the words. Our dogs and cats will sit and listen intently when I do my practice. I'm not too sure if they are able to reflect on this though. But who knows.
They also sit or lay around very peacefully when I meditate. I feel fortunate that our home is almost always a very peaceful place to be. I should mention I'm the only Buddhist in our home, but there is no "issue" with that, my family accepts this.