Yes, that condition can happen. I worked in my husband's veterinary business for almost 30 years and have seen this with some patients--usually older ones. It has to do with lots of small blood vessels leaking. It does get better though. Always helps to keep them quiet after surgery.

Just like people, each pet reacts differently.
If you see any pussy discharge from the incision then you need to get him on some antibiotics for infection.

Hope he shows continued progress.

Chris

When my son had Argus, his pound puppy GSD, neutered I thought he had had replacement implants. The vet said the swelling was not abnormal and it did shrink. She thought my question about implants was hilarious.

It is normal, since all dogs don't heal the same.

What I did with my dog when he could not eat wearing the e-collar, I got a real cheap one. I cut it to half the size and put it on backwards. he could not reach himself but was able to bend to eat and drink. Not that he was much interested anyways, but at least I knew he was able to reach.