Of course the pet carrier would have wheels. You don’t expect him to WALK all the way to and from the petplace, do you?
Oh, well it’s a simple matter then. All you have to do is convince the wife that the cat snagged your belt loop with a grappling hook attached to its leash, while you were just innocently walking through the neighborhood.
Tell her you had a feeling you were being followed, but you didn’t see anybody.