Ask The Vet: Why Do Dogs Poop Black?
Dr. Ivana Crnec
Dog poop is not a fun and fabulous topic to talk about. In fact, it is stinky and more often than not, it can be gross. However, if you are a responsible dog parent, chances are you will have to deal with many stinky situations on a daily basis.
Putting the jokes aside, your dog’s poop offers a plethora of clues and tells you a lot about your dog’s digestive health. To be more accurate, your dog's poop is ultimately an amazing indicator of his overall well-being.
Therefore, keeping an eye on the appearance of your dog's poop can be quite helpful. Do not worry - you do not have to become a ‘’poop patroller’’ and check your dog’s poop every time it does it business. However, keep in mind that your dog’s poop needs visual inspection at least once in two days.
What to Look For in Normal Dog Poop
When examining the dog’s poop there are six criteria that require evaluation. Those criteria include: color, consistency, content, coating, size and frequency. Let's take a closer look at some normal and abnormal colors of dog poop.
Normal dog poop is chocolate-brown in color. The color is due to the presence of bilirubin (a chemical compound produced in the liver). The bilirubin is further degraded into urobilinogen and then stercobilin. In fact, it is the stercobilin that gives poop its distinctive usual color.
However, there are slight color variations from one dog’s poop to another dog’s poop. The color deviations can be due to several factors such as:
Diet – when determining the overall appearance of the poop, the dog’s diet is the most important factor. As for the color, if a dog eats raw diet rich with bones, the dog's poop will be white or grey shade.
Dyes and colors in the food – artificially added colors and dyes cannot be digested and are passed with the stool. If they are strong enough they can change the overall coloration of the poop.
Level of hydration – if the dog is well hydrated its poop may be paler. However, on the other side, if it is severely dehydrated the poop will have darker shades depending on the level of dehydration.
Medications-Some medications can influence the color of the poop. If your dog recently started taking some new medications the color alterations are most likely die to active substances in the drug. For example, Pepto bismol can turn a dog's poop black due to its bismuth sulfide content.
Although the above mentioned factors can influence the color of the poop, the changes are usually not very dramatic.
Different Poop Colors in Dogs
Yellow poop – yellow poop in dogs means that the dog’s intestinal motility is increased. Because of the increased passage pace, the stercobilin does not have enough time to pass its distinctive color to the poop. This is common in digestive disorders like exocrine pancreatic insufficiency and IBD (Inflammatory Bowel Disease).
Bright yellow poop – associated with liver problems, pancreatic problems and gall-bladder problems.
Bright orange poop – indicative of liver and gall bladder issues.
Green poop – usually indicates that your dog eats a lot of grass. Keep in mind that dogs tend to eat grass when troubled by gastrointestinal problems.
Grey poop – suggests either disturbed nutrient absorption or liver problems.
Raspberry-jam poop - is associated with severe inflammations that leads to sloughing of the intestinal lining. The poop is not only changed in color, but also contains small chunks of tissue. This type of stool is characteristic for hemorrhagic gastroenteritis.
Red streaks – the presence of bright red streaks or drops are indicative of bleeding in the lower intestinal tract.
Dark black poop – suggests that there is digested blood present in the poop. This condition is known as melena. Melena is most common in dogs with gastro-intestinal bleedings from ulcers in the upper intestinal tract.
In general, if an abnormal color persists for more than two stools or two days in row (depending on how frequently your dog poops), it is recommended to call your veterinarian and have your dog thoroughly checked.
Why Do Dogs Poop Black?
The passage of black, tarry stools is called melena. Black, tarry and sticky stools indicate that bleeding is occurring in the gastrointestinal tract. Melena is not a disease but rather a sign of disease. Effective treatment involves finding and eliminating the underlying cause of bleeding.
The most common causes of melena in dogs include the following:
Swallowed blood – the dog can swallow a significant amount of blood if it sustains an injury or disease in the nose, mouth or esophagus.
Bleeding in the stomach or intestines – this can occur in cases of stomach or intestinal inflammation, ulcers, tumors or presence of certain types of parasites such as hookworms and whipworms.
Internal bleeding caused by ingestion of drugs and poisons – prolonged use of corticosteroid drugs and non-steroidal anti-inflammatory drugs can easily lead to gastric bleeding. The popular rat poison called warfarin has similar effects.
Internal bleeding caused by foreign body – dogs are voracious eaters and can often ingest non-edible items such as peach pits, toys, small bones or pebbles. These objects can severely damage the lining of the digestive tract and consequently cause bleeding.
In a nutshell, if the poop is black it indicates bleeding from the esophagus, stomach or small intestines. On the flip side, if it is bright red it indicates bleeding from the colon, rectum or anus.
The Bottom Line
Pay attention to your dog’s poop and think whether something happened that could have triggered changes in its appearance. For example, have you made a change in your dog’s diet; or has your recently been treated with any medications?
If there are no obvious reasons, observe your canine baby for other signs and symptoms. If in doubt, bring a sample to your vet’s and have him examine your dog – if only to put your mind at ease.
About the Author
Dr. Ivana Crnec is a graduate of the University Sv. Kliment Ohridski’s Faculty of Veterinary Medicine in Bitola, Republic of Macedonia.