Puppy throwing up :(

Alli • Grace 10-8-18 ❤️❤️

A few nights ago, my 5 month old puppy threw up in the middle of the night last night he did it again. It's always in the middle of the night. I've never owned a dog before so I have no clue what to do! But I feel bad for him and it's staining our comforter so I want to help him!