A month ago my wonderful husband accidentally bought a different brand of dog food for our golden retriever Barley. Usually when you switch dog food there's a chance that the dog will vomit and have diarrhea. To avoid this it's best to mix the old food with the new food to make the switch gradual.
Fast forward to the other day where yours truly had to make the switch back to the better food he was originally on. However, my wonderful husband didn't leave any of the old food for me to mix with the new food.
Poor Barley had the adverse reaction to the food switch this time. So I did some research to find a treatment for the doggy tummy problems. I found through a few different websites that you can give your dog pepto bismol. Make sure you research how much to give per the weight of your dog.
Also its best to withhold food for 12 hours after the vomiting and diarrhea. However make sure they have more than enough water to ensure they don't get dehydrated.
After the twelve hours I found that dogs should have a bland diet to ease the stomach when they have such issues and ease them back into the dog food.
A couple different recipes for the bland diet can be found here.
I made 2 cups of boil in the bag white rice mixed with some chicken baby food and Barley ate it right up.
Good thing I have a few days off before my new job starts to take care of him.