What is the best dog food for a sensitive stomach?

Across the reviewers we read, two formulas dominate sensitive-stomach discussion: Purina Pro Plan Sensitive Skin & Stomach (Salmon & Rice) and Hill's Science Diet Adult Sensitive Stomach & Skin. Both draw repeated praise in specialist subreddits for firming stool and being tolerated by dogs that reacted to other foods, and both brands run documented feeding trials. Individual results vary, so a slow transition is widely recommended.