Are you switching foods slowly? It is best to take at least 7 days to make the switch by adding the new food in with the normal food adding more and more of it until at about a week they are eating just the new food. Sometimes during the switch if it happens too quickly they will get runny stools.
Here is a a good switch over schedule (ratio of new to old food)
Day 1: 1:5 new to old food
Day 2: 2:4 new to old food
Day 3: 3:3 new to old food (half and half)
Day 4: 4:2 new to old food
Day 5: 5:1 new to old food
Day 6: all new food |