Is this normal?

I couldn't say for sure either way, but my instinct would be to ring the vet with a description -- they'll probably know straight off if it's something that needs their attention.

This is most likly a reaction to internal stitches. I think it is called edema. Very common with abdomen incisions

I'm glad you called the vet as that would have been my initial response. But, since you've done that already, I did want to talk briefly about my experience with spay incisions (I understand it was a neuter, but, for all intents and purposes, the abdominal surgery would have made the incision more similar to a spay than a neuter).

When my cats and dogs were spayed, they all had a slight reaction to the sutures that were used. My cats' reactions were less than my dog's reaction, but there were some extenuating circumstances there. I, like you, thought that the incision should be flush with the skin, but it wasn't like that. In fact, the reactions I saw were very similar to what you described with your Harvey. I called my vet and had each animal brought in almost immediately after I noticed that the area was swollen. And, each time, I felt like a fool as I walked out of the office for something that was absolutely normal.

My vet's take on this, especially where cats are concerned, is that many cats who have abdominal surgery have a reaction to the sutures. All of my animals have had the stitches that dissolve on their own and I have been informed that a reaction to these stitches is not uncommon. Though the regular stitches can also still cause a reaction. In some cases, my cats had a reaction that looked as though an abscess was forming underneath the skin surrounding incision (I was later told it was a reaction to where the sutures were tied). But, my vet assured me that it's not usually an emergency so long as there is no blood or fluid seeping or the area is not red or warm to the touch. But, still, seeing a swollen area is quite concerning and it's something I would still have checked out since there is a very real possibility of infection or abscess following surgery.

Either way, I would continue to keep an eye on Harvey's incision site and call your vet if you have any continued concerns or questions. It's stressful when our babies have surgery -- even when it's something as routine as a spay or neuter. It sounds like Harvey's on the mend and will continue to heal well and I send you and your kitty loads of vibes for a short recovery time and a positive visit with the vet tomorrow. Good luck and keep us posted!