He should be ok.
You can request that your pup goes first although the vet would only be doing it to "appease the owner"... Cats usually go first. They take longer to come out of anesthesia. However, he can have fluids via IV which (I think) contains sugar.
Ellie doesn't have a problem with fasting, so I don't ask the vet to do her first. She does gets fluids throughout the procedure though.