Is it ok for a dog to eat a small amount of worchestershire sauce on his food?

It's probably not dangerous, but I wouldn't do it. Worchestershire sauce is very high in sodium, which can adversely effect a dog's kidneys. Furthermore, it isn't providing Fido with anything except a salty taste. Try adding a small amount of canned dog food made from fish to add protein and vitamins as well as a pleasant, savory taste.