The cause of a dog's tarry black stool must first be checked. Generally, gastrointestinal bleeding, improper diet, or peptic ulcer and other diseases will cause the dog to have tarry black stool. It is best to take the dog to the pet hospital for examination first. Identify the cause and then treat accordingly.

Tips:

Pay attention to your dog’s diet and do not feed your dog random food, especially human food, to avoid causing gastrointestinal diseases in your dog.