How can he smell of cat and have that evasive reaction?
Never mind. Experience.
Is your greyhound male? Had a Great Pyrenees once a long time ago who would cuddle up with my cat, or was it the other way around? Anyway, they were inseparable.
It’s his cologne: Catatonic.
If he thought he was the only cat in the world, then how would he know how a cat smells?