It can mean one of two things--either to Hypnotize a woman into believing she's a domesticated animal--a cat, a dog, a rabbit,
etc.--or it means to Hypnotize a woman to behave like a human pet--adoring, obedient, crawling around on the floor in the nude when at home, enjoying being scratched under the chin or on the belly--stuff like that. (Eating out of a bowl on the floor is strictly optional.)
Either one has strong erotic potential, and I admit I've had fantasies about the latter--
"Now, my lovely darling--tell me what you are."
"Master, I am your pet--your adoring, obedient, Hypnotized pet."
"And what will you for me, my pet?"
(Purring) "Anything you ask, Master."
Hope that helps.