best ask your vet as it may depend on what time of day they are having their ops. Usually they are ok with something mid evening the day before but nothing after that (at least that's what I've been told to do). With both Mosi (neutered 3 months ago) and Jaffa (had a dental recently) I gave them a little bit of dry food around 9pm and that was ok, but I'd give nothing later than that. No breakfast on the day.
Ruby just got spayed Monday and it was no food after 10pm. She had an early morning surgery. She was allowed to drink water right up to dropping her off.
Our vet says nothing after 10pm the night before. I usually drop off my kitties on my way to work in the mornings with a baggie of food for them to eat after their procedure.
with all of my critters (dogs, cats, a rabbit and a guinea piggie), they always went to the vet first thing in the morning and vet always said no food/water after 9pm.
It is seeming to me that all vets advice a little differently.
With some I've had cats cut off food at 10 p.m. with water always available. Then it was changed to no food and water after 9p.m.
Another said no food or water after 8 p.m. and the new one I am using says no food after 8 p.m. and no water after midnight.
I've always kind of used 9 p.m. as the cut off time for food and water, figuring that by the time I get the cat in for their surgery and it actually happens then it will be 9 a.m. or after and they will have been fasting for a full 12 hours.
So far I've had no trouble with cats vomiting and having problems that I've been told.
I would have thought 8pm would be fine - but if the vet said 6pm maybe you better ring them and double check. What time are you taking them in? If the vet plans to do them early in the day that may be why s/he said 6pm.
We haven't been told the exact time of the op but we think it will be about 9.30am.
I always thought it was just 12hours to leave the cats starved. We either take there food away and 6pm or 8pm and they can have water over night but when we get up in the morning (about 7am) then we have to take their water away.
It's funny how different vets say different things isn't it.