In some dogs it is not unusual to notice a mild diarrhea following a change in food. This is particularly true in younger animals. In most instances it persists only until the dog's intestinal tract adjusts to the new food. In rare instances the diarrhea resulting from a change in diet lasts longer and may precipitate more serious forms of diarrhea.
To prevent diarrhea from developing during a dietary change, make the change gradually. A gradual change allows the intestinal tract to make a slow transition from the ingredients and physical characteristics of one food to those of the other.
Should diarrhea develop despite the precautions taken, reduce the amount of food being fed by one-half for a day or two. If this fails to correct the upset stomach then return to feeding the old food until the stool is normal again. Should the addition of the new food a second time also precipitate diarrhea, it is probable that the new food does not agree with your dog. If a third food is available it may be best to try an alternative method rather than to continue to subject your dog to a food that fails to agree with it.