A. A cat should never get stitches on a wound unless it is terribly disfiguring. Wounds from bites and scratches harbor lots of bacteria, and so on closing it with sutures you simply close the bacteria inside. I suspect he is chewing at it because it is uncomfortable. The wound should be cleaned and then an antibiotic should be given - injectable or oral. The only way to prevent this is to keep your cat indoors. Cats outside will inevitably interact with other cats, and most wounds (in my experience) get infected and become abscesses without the help of an antibiotic.
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