Fox attack on my cat

We are often told that cats will "see off"a fox and are not in any danger of attack, but we have just had to take our big,strong ginger tom to the vet for an operation to clean and stitch up numerous large wounds that the vet says were almost certainly caused by a fox. We live in the country and often see foxes around, so are now very apprehensive, especially as our puss is an outdoor type and hates being shut indoors. At the moment ,we HAVE to keep him in as most of his fur had to be shaved off for his wounds to be stitched.I've made him a kind of coat out of a jumper sleeve, cuff around his neck and a couple of holes cut out for his legs to go through so that he is warm and can't chew his stitches!