Mac was nuetered 2 weeks ago. When I brought him home he drank a lot right away. Then within a half hour he was eating too. Give him an hour or two and he should be going in the litter box. I know it took Mac a couple hours but I figured it was since he hadnt ate or drank since the night before surgery. Mac just turned 6 months last week and weighs 9lbs. He is a big kitty but not fat. He looks almost as big as my 1 1/2 year old cat.He's back and seems fine.
The only differences are that he's thirsty and drinking lots of water, and he crouched in the litter box once as if he were going to pee, but the litter was dry.
At 6 months he weighs 7.5lbs fasted.