I wonder, are there no suggestions on what would help him and prevent the abcesses?

For example, with my dog, Tasha, her anal glands often get impacted, then she scoots, that causes irritation which leads to infection. Off we go to the vet, they manually express the gland and she gets antibiotics to clear up the infection. Sounds similar. Thing is, for Tasha, the vet said this means her stools are not large enough to express the glands automatically, naturally. So I have to bulk up her stools, but giving her 2 tablespoons of canned pumpkin with her food.

It isn't a matter of making the stools harder, or softer; they just need to be larger to press the glands. Think of it as a small marble passing through a 2 inch piece of PVC. Too small. A tennis ball would be about the right size though, to move and also press against the wall of the pipe.

I don't know enough about the cats to do other than raise this. Have they made any suggestions as to things you can try before surgery? Maybe ask the vet if you do that with Karen!