What to do if my dog has black loose stool but is otherwise energetic?

A dog passing black stool while in good spirits is mainly considered a symptom of bleeding in the front part of the digestive tract, possibly from swallowing a foreign object that scratches the intestines and causes bleeding in the stomach or front intestine; if accompanied by vomiting or loss of appetite, take it to the vet promptly. Second, the dog may have eaten foods rich in melanin, causing loose stool from indigestion, in which case an appropriate amount of pet probiotics can be given and the dog observed for two days. Finally, infection with intestinal parasites may also cause intestinal bleeding and loose stool; if loose stools are frequent, a veterinary visit is recommended to avoid missing the best treatment window.