I was told if a pup is congested he may refuse to eat if he can't smell it. Maybe he can't even smell the extra pungent food and even if he can smell it a little it maybe it doesn't smell appetizing with his congestion and that can be from the intranasal vaccine maybe some side effects. I know their appetite is scent motivated which is why alot of kibble has that chemical to make them think it's appetizing when they sniff it when without it they wouldn't want it. Someone here told me that or I read it during recent research. But I do remember reading about most dogs and cats not wanting to eat while congested or having a cold that made them stuffy or runny bc I recently dealt with the same thing with two kittens. It's good you have an apt set up hopefully your chi will get his apt back before but either way the apt will give you clarity and put you at ease to know instead of assuming. Keep us updated of you don't mind I'd like to know what caused his appetite problems for future reference. My girl Padme is a really weird eater too sometimes she eats three times a day regularly sometimes she will leave it all day and eat it all at once at night other times she just nibbled throughout the whole day but she's going through a weird puppy growth spurt and looks all lanky and looks too thin except for right after she eats she also lost all her puppy fur that made her look thicker but since this growth spurt her appetite has been off and she seems really picky I have to add water to barely coat her food on days she doesn't seem interested so maybe he's going through an odd stage if it isn't the congestion or maybe both.. I hope it goes well though and he's eating soon and back at 100%.