Fred, I've cropped as suggested. I had thought about it before, but was a bit concerned I'd lose the "forest" effect as in the second line of Blake's poem (forest of the night). But I hope this will retain enough of that, as I definitely agree with you about the crop.
Arie was actually panting rather than hissing, as it was hot and humid, and he'd been running around like crazy. He has a thick coat and seems to mind the heat. But I thought he looked kinda evil.
Intense eyes indeed and quite an expressive face. I think cropping off quite a bit from the right (almost to the beginning of the cat's ear) and a tad from the bottom (almost to the chin if the cat) would increase the impact. Just an idea for an already good cat portrait.
Cheers! Fred