Keep an eye on the nose, not a huge problem if other strange behavior isn't occurring. However, if his nose is almost completely covered, take a soft wet tissue an wash it. Cats smell their food, and if he can't smell it, he isn't likely to eat it. Also make sure he has a fresh bowl of water in his eating area at all times. Some folks don't understand how important water is in a cat's diet. Once had a stray who lived on my porch for a couple of years, he wouldn't come in, he was too feral, and it had a crusty nose and wouldn't eat, and as soon as I washed it (that was fun!) his appetite increased. My spouse called the vet and I had done the correct thing.
