After Cassy ate the dianthus (small flower of the carnation family -- poisonous for felines) the emergency vets had me whisper to him to verify that he wasn't slipping into lethargy.

Apparently a sleeping cat's ears will swivle when you whisper to him/her, but a lethargic cat's ears won't. So after we got off the phone I was to whisper to him at 15 minute intervals and to rub his tummy and paws to check for soreness at hourly intervals for the next 4 hours. Cassy seemed to enjoy the attention, and turned out to be fine.