Cat fat infection?

Question
My dog bit a neighbor's outdoor cat. I am paying the vet bills.  The vet put the cat through surgery to place a drain for what is apparently an infection of the fat around the puncture wound.  Is this common?  They are also saying that the cat needs an additional surgery later to remove what sounds like scar tissue.  This after the cat seemed like it was going ot recover just fine.  Also, the cat was on antibiotics...?  I don't know anything about cats.  Is this standard of care?

Thanks.

Answer
Yes.  Cats often get abscesses, which is a spreading infection under the skin.  It is common for the infection to spread out 2-3 inches from the initial puncture.  Even when the bacteria are killed off, the infection needs a drain hole to allow fluid to escape so healing can occur. If the hole closes up and the infection and fluid are not resolved, then it will re-open in many cases.