Why does your puppy have green diarrhea?

A change in color or consistency of feces can stem from many reasons including a simple change in the type of dog food given. Certain commercial dog foods which have dyes in them to color kibble can cause green colored feces, but it shouldn't cause diarrhea.

Puppies with any change in color or consistency of feces should be seen by a veterinarian to ensure that there is not a serious health concern such as parasitism or disease that has led to the change.