Sufficient water in the food helps. Many dogs get acid reflux because the sphincter muscle at the top of the stomach doesn’t close completely if the dog isn’t producing ENOUGH acid. Acid production is affected by water in the meal. For my dog, adding water and apple cider vinegar(raw with the mother) to his meals stopped his acid reflux within 24 hours. The only time he has ever had issues again was when I accidently fed him something he has a food sensitivity too. And by the way this works for people too. I drink a slug of dill pickle juice and my acid reflux is gone.
