Synaesthesia

Ojuice5001,

I can't provide a definitive answer because, quite fankly, we have only just begin assessing the range and dimensions of functional similarity between the brains of various species.

The key point is that we can scientifically study the capacity of a brain to evaluate it's own state. Thus, despite the failure of the human ability to imagine a whole animal brain, we can determine whether and in what sense various animals are conscious.