How often does your dog...?

I have a Jack Russ also. He loves gr! He is like a cow. I asked the vet about it and the vet said it could be because he has an upset stomach or just loves gr. But he never did throw up. I would watch for treats like certain dyes in them. Because that can bother their tummies. Or you might want to change the food also. I use Benefield dog food. I don't use wet food because it does upset his stomach. My dog doesn't shiver but his dad shivers alot. The vet said that it's normal. But with everything else that you have said. I would call a vet or take the dog to vet. Specially if it's only a puppy.