This is Dr. Christian. Welcome to JustAnswer. A few questions will help me get a clearer picture of the situation:
This is Dr. Christian. Welcome to JustAnswer. The good news is that Sampson is a bigger dog so this has a better chance of passing. The meal was a good idea since it may help this pass. Try feeding canned pumpkin with his meals for the next couple of days. The fiber in the pumpkin may also help this pass. If he stops eating, becomes lethargic, starts vomiting or has belly pain then have him seen immediately since those are signs of a possible blockage. If you have more questions please let me know.