I definitely think scent plays a role, too. Years ago, when our 15-year-old cat was still a young'n, we bathed him outside.
His dog "sister" (RIP Buffy, a stray Heinz 57 who died a few years back) also got a bath. When they were reunited, the cat went nuts.
He attacked the dog. He attacked us. He wouldn't go near any of his beds. He wouldn't eat. He ran around almost incessantly. This went on for a day or two.
After that, it was as if nothing had ever happened. It was odd. We never used that shampoo again though!
