I just had Snoopy neutered last Thursday, the vet didn't preform and pre-surgery blood test, because he is only 9 months old and he recently preformed a body check. If you have been taking Smudge to regular annual check-up and he has been an healthy, I wouldn't worry too much.
First nigth after the Surgery - From what I have observed from Snoopy, the night right after the surgery, he is very quiet, didn't ask to come out (because he would bit the cage when he wants food and play). But I had to make sure that he poop and pee, as soon as I saw he able to do both, eats and drink. I was relaxed. However the first night, besides the water bottle, I also gave him a bowl of water and also move the location depended on where he lay in the cage, so he can have easy access to the water. He did eat less that night, but at the same time I encouraged Snoopy by giving him more of his favorite treat than he would normally have.
The Next Morning - as soon as I get down to the living room, I saw him acting like he normal do, biting his cage, instead of asking for food that morning, he asked for play time. Because he still had food in his bowl, so I knew he wanted to play, specially when I open the cage door and he was like ready to jump out. Of course I didn't let him out, because too soon to let him have too much excerise after the surgery. I checked his cage, he did pee and poop, so Snoopy is back to normal.
I searched onine and the vet told me that it will take some time for the change to happen, so I'm still observing the change right now. Today is only the 4th day after his surgery, and he is just normal as usual. I did let him come out to play over the weekend, but I think I will stop give him play time until the upcoming weekend, because I afraid that is surgery area won't heal as good, if he continues to have too much running around. So i may just spend more time with him at the cage.
Rather he is mad at me or not, I think he just doesn't like me when I have the towel in my hand, because he knows that I will have to pick him up. I need to do that because I need to give him medicine and to use peroxide to clean his wounded area. That is a tough job. I always have
trouble turning him over and able to keep him still until is finish (which only take a few seconds, tap the cotton ball on it) but I always have to use a good 5 minutes and do it little by little. Feeding him medicine isn't that bad, because the Vet told he would love it, and it is true, no problem giving that to him. After the whole medicine and cleaning process, I would give him treats, and yes he doesn't come to me for the treat at the beginning when I give him my hand full with his favorite treat, but after a few more minutes he is okay. So i think he isn't mad at me, just doesn't really want me right now, but it is fine, after his sutures removed in another 1.5 weeks, he will forget what I had to do with him. OH... Very important... when I give medicine and do the cleaning, I always do in the kitchen, because I have a gate (he used to live in the kitchen and play in the kitchen), so he can't go too far and I can catch him again when he escaped from me.
That's all the information I have, hopefully I'll see more changes very soon and share it with everyone this process. But right now he is still the same the old sweet and cute Snoopy