Vets closed Sunday - Dog refusing Hill ZD food after 1 week

Long story short.

My lab is 5. I’ve had him since early January.

He’s been on Hill ZD for a week. The past two mornings he’s refused his breakfast. He ignores his puzzle toys (I have like 10 because I love him and he won’t play with toys).

I’ve frozen kibble. Soaked them. Blended with water. Frozen that. He only gets them in puzzle bowls. Yesterday I tried scatter feeding in the yard.

He bolts upright when I move a bag of cereal or chips or something. Yesterday he did eventually eat his breakfast at 2pm instead of 7am. Then at 5pm he wanted his dinner.

He will eat his training kibble and his “good job getting in the car,” kibble.

This morning my apartment was cold but I noticed him full body trembling while I was having coffee before bathroom time.

I would call and ask my vet but only emergency rooms are open currently. I’m thinking he’s just being a fussy butt because he used to get a lot of treats.