William was a fussy eater when he was a puppy and I used to worry endlessly and tried adding all sorts of things to his food.
In the end I became "tough mummy" and would put his food down (JWB kibble at that time), usually with a bit of warm water added, and if he hadn't eaten it within a few minutes I would calmly pick up the bowl and throw the food away, ignoring the shocked spaniel eyes. It also helped that he was occasionally fed at my friend's house with her Golden Retriever. Ruby ate William's food a couple of times while he was faffing about playing with it and my friend didn't refill his bowl, but left him without until the next mealtime.
It worked within a very short time and he's had no eating problems since. If you're sure that Milo is well and not ill, perhaps you could try as above for a few days? He might lose a bit of weight but he won't starve himself and will eat up when he's hungry.