My pet's hunger was 6/10 last night. I fed him a couple things, but it didn't change. I figured it might be buggy so I just left him alone till today. Now it's 4/10. I fed him and it still didn't change. How does hunger work in this game?

Recently it was decided to make pets hungry faster and staff told the users that they are monitoring and adjusting things. That might be a reason why it is a bit wonky, but honestly, nothing will happen if your pet has only 0/10 hunger - since you will not be able to battle with that pet only. (just do quests and feed all food you get to your pet for the gourmant achievement ;) )

Okay, thank you! :D