I checked him out, and it looked kind of swollen and it was definitely bleeding. Time to go to the vet.
I called work and told them I wouldn't be in while Cathy made the call to the vet's office. They got me right in, even though it was right between surgeries.
I took him there, and the vet looked at him for a moment. He said he thought that the stitches were starting to irritate the skin, and that it looked like they needed to come out. He said that the rest of the paw looked really good, and got to cutting the stitches out.
He told me that after stitches have served their purpose, they can start to irritate the skin as an animal (or a person, even) starts to use the part of the body that has been stitched again. I had noticed that Cooper seemed to be favoring the paw again a little, and as soon as the stitches were out he was putting weight on the paw and running around again. I think that the stitches knots were digging into his skin, and it was bothering him.
He's been sleeping most of the day, and already this evening the area looks less inflamed than it did when I took him in this morning.
He has another appointment on Monday, so the vet will check him again then. Hopefully, he'll be all good!!!