Dear Steve: I would guess it was a hairball problem, then, and hopefully if Loki has been able t cough it up, finally, he will go back to eating normally. Most of my kittys manage to cough up hairballs when they need to without a lot of extraneous vomiting, but I do have one cat, not a longhair, either, who before he can get them up often has several days of digestive distress then not wanting to eat at all before he can finally get it up. The first time he did this I was really freaked out and jumped through all kind of hoops worrying about the food and trying this and that and finally up came the hair ball. Here's hoping the solution will prove to be so simple for Loki.
Sally in San Jose

