Figuring out the food ingredients that are causing your dog's upset stomach is not a rocket science. You only need two things: patience and a lot of willpower.
Start by eliminating all the unnecessary items in your dog's diet. These include extra treats, human foods, and anything that belongs in the trash bin. It is also important to keep your dog away from trash scraps your dog might be nibbling throughout the day--as this might be the cause of their never-ending stomach problems.
Some dogs can eat just about anything while some experience discomfort from the slightest change in their diet. Here are some food ingredients that might be causing a fuss in your dog's tummy:
There are some dogs that cannot digest certain types of protein. You may try switching their chicken-based diet--for instance--to lamb, beef, or fish and observe what happens.
High-fat diets are much harder to digest than high-protein or carb diets. Check the label of your current food and if it happens to have "fat" or "oil", it may be time to switch to other brands.
Don't be too afraid to ask the manufacturer about the ingredients listed on their product packaging. Choose a company with third-party clinical studies performed on their brands to ensure the quality of their products.