dog has got black stool
Report Abuse. Usually a dog who has black stool is not getting the right kind of food because they tend to go eatting from the wrong sources. I had a dog(short haired) collie who had this problem. I took a sample the day of the appointment(when he first had one) and brought it in.eport Abuse. Usually a dog who has black stool is not getting the right kind of food because they tend to go eatting from the wrong sources. I had a dog(short haired) collie who had this problem. I took a sample the day of the appointment(when he first had one) and brought it in.