I don't think my Vet would give me instructions on how to kill my own cat. My vet also suggested Benadryl for Buddy after her rabies shot when she scratched the area where the shot had been administered. I didnt have to give her Benadryl because she was back to her normal self the next day. I'll take a certfied Vet who's been in business for 15 years advice over random commenters on the net, any day. I'm saying this because of other hysterical comments (old and recent) that I've read on this site concerning giving cats Benadryl. It IS safe for cats if you give the correct dosage.