Aww, poor puppy. Hope it's nothing and he's back to usual soon.
And, he does look better. Really. His face isn't so bony and his legs are a bit more chubby, or so it looks to me. Glad he'll have a vet look him over and make sure he's doing well.
I swear, with every photo you post I want to be able to reach over and tug on his floppy lips.
Who's a big squishy, you are, yes you are!