We can't apply spot-on parasite treatment to LMC, she has to go to the vets. Just opening the stuff sends her running and there's no way we can restrain her – it takes a vet and three veterinary nurses and even then, she's got one shot to get it on, before LMC squiggles free. She can't be restrained twice without the administration of a general anaesthetic.
Bad Cat, on the other hand, doesn't even notice.