Join Date: Oct 2012
Location: Washington State
A couple hours is pretty normal I think. My vet keeps them overnight and I pick them up the next day, so 12+ hours post surgery and they were all fully awake and ready to go, even the adults. My friend who had her 6-7 month old female snipped said she was groggy for 12-18 hours after. That's longer than I'd expect, but she pulled through just fine, no additional vet care needed.
With the vets I've used in the past, or with surgeries other than spay/neuter, it takes several hours to bounce back, on average. Our kitten who had surgery for his pectus excavatum (chest deformity) was groggy for days after, but he was 1. seriously ill (hence the need for surgery) and 2.) on some REALLY good pain meds, which made him seem "drunk" on their own.