My vet NEVER keeps them overnight for spaying or neutering. He's spayed or neutered at least 8 of my dogs (both past and curent) - and there has NEVER been a problem. Even when Lottie was spayed during her c-section, she came right home with me - and when Chloe had her anal glands removed she came home the same day. I think unless there is some serious problem with the surgery, they are probably better off in their own homes. My boys usually wake up feeling fine - the girls take a little longer. My biggest problem is keeping them QUIET for a couple of days.