What might make a dog's stool have green areas on it?

My dog is a Chihuahua that recently turned 7 years old. Today, for the first time, I noticed that her stool had a green "surface" on it at first and then, after looking closer, I noticed the normal brown color in some other (smaller) areas. What could cause this and what are the symptoms I should look out for? This is very worrying and I need to know how serious this is before taking additional steps.Thanks in advance and, please, provide serious answers only.

Green Feces in DogsKnown causes of green feces in dogs are intestinal disorders and parasite infections. The stool appears slimy and green in color. Watch for symptoms of constipation, straining to defecate or diarrhea, as it helps the vet establish a correct diagnosis. In certain cases, parasites go undetected in the first fecal exam, and the vet may recommend a second stool examination. Green feces in dogs could also be attributed to ingestion of grass or allergies caused by certain ingredients in food.As fecal exams determine underlying illnesses, vets generally use a stool test as a diagnostic aid for pets with varying symptoms of sickness. Fecal exams should be conducted at least twice a year in order to detect parasites and bacteria. Remember to follow adequate feces disposal methods, as dog feces may contain parasite eggs, and infections could be easily transmitted to other pets.Read more: Canine Medical Problems Indicated with Dog Feces - VetInfoAlso read the poison warning listed below if the green in the dogs stools is bright neon greenhttp://www.perfectpetcollars.com/