When you think about it, the Doctor is a bit like a cat. He turns up where you least expect him. He has mysterious adventures out of sight of the human race. He always lands on his feet — eventually. And you suspect he can size you up with a single look.
For more info about using essential oils for cat (contrary to mislead belief, essential oils are NOT toxic to cats) please refer to Melissa Shelton, DVM who uses essential oils in her vet office. She has a doctorate of veterinary medicine and has used essential oils extensively in her office with animals, including cats.