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What are Passing Black Stools?

It is vital to be aware of the consistency and color of your pet’s feces for the sake of his health. While your dog cannot tell us verbally what is wrong with him, by being observant, you can read the tell-tale signs if a health issue arises. If your dog has started passing black tarry stools, then it indicates the presence of digested blood in the feces, known as melena. For the stool to appear black, there must be a significant amount of bleeding into the stomach or small intestines. Note that bleeding into the colon or rectum (hematochezia) appears as fresh blood in the stool. Any amount of internal bleeding is a serious concern. The passing of black stools could occur due to any of the following conditions: 

  • Injury to your dog’s digestive system
  • Infectious agents 
  • Hemorrhagic gastroenteritis 
  • Gastrointestinal ulceration 
  • Cancer

Why Passing Black Stools Occurs in Dogs

Injury to your Dog’s Digestive System

 

A black, tarry stool (often very smelly) indicates that there is old blood somewhere in your dog’s digestive system, and internal bleeding is a concern. It may stem from an injury to the GI tract from the indiscriminate eating that some dogs are famous for, such as the ingestion of sharp twigs, parts of toys, and other random items.

Infectious Agents 

Intestinal disorders such as intestinal parasites, bacterial, viral, or fungal infections need to be ruled out as the cause. Any of these agents can cause internal bleeding within the stomach or small intestine as the parasite burrows into the lining of the organs. If they are the cause of the black stools due to internal bleeding, then treatment will be initiated to correct this condition. Needless to say, it needs a specialist’s intervention and care. 

Hemorrhagic Gastroenteritis

While the cause of hemorrhagic gastroenteritis is unknown, it needs immediate treatment to prevent your dog from dehydration and to prevent death; it is a very serious condition. The diagnosis is likely to be confirmed with a blood test. If your dog has this condition, the tests will reveal elevated packed cell volume levels (PCV). 

Gastrointestinal Ulceration 

If your dog is experiencing this condition, it can be caused by one of the three most common causes: hepatic (liver) disease, the use of non-steroidal anti-inflammatory drugs and neoplasia, which is the abnormal growth of cells. Your dog may show no other signs of discomfort, or they may experience a lack of appetite, weakness and pain in their abdomen. There are many causes for this condition, and it needs instant attention from a veterinarian.

Cancer

 

No one wants their beloved dog to be diagnosed with cancer, but unfortunately, it can happen. It is common knowledge that the sooner cancer is found, the better chances of treatment and extending your dog’s life. While the passing of black stools does not necessarily indicate cancer, the quicker you can have it checked by a veterinarian the better for your dog. Observing your dog and noticing any symptoms is important, so if your dog has behavioral changes, lethargy, loss of appetite, unusual weight loss, and unusual odors, then it is advisable to get them to the clinic for a few diagnostic tests.

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What to do if your Dog is Passing Black Stools

The first thing to do is to take your dog for an immediate physical examination with your veterinarian as black stools are an indication that all is not right. If you can take a sample of the stool to show the specialist, it may help in the diagnosis. Treatment and cost are determined as to the illness that your dog may be experiencing. 

If your dog has eaten something that is causing the internal bleeding (due to a sharp or pointed object), it may be that your dog needs surgery to remove the offending object. Your pet may need a few days in the hospital after the operation but should recover quickly and just require a course of antibiotics, rest and care once home. 

In the case that your dog is suffering an infectious condition or is battling with parasites and bacteria, a course of the appropriate medication will help overcome it. Often, your dog will have a follow up examination and tests to determine if the medications have been effective. 

For hemorrhagic gastroenteritis, it can be a problem to find the exact cause of the problem. To diagnose the ailment, your dog will require x-rays and blood tests. But if these tests do not help confirm what the problem is, then a biopsy may need to be done. The biopsy can be done via an endoscopy, or a biopsy can be surgical. These samples can help determine the treatment. 

As dogs mature they can be prone to some form of cancer, and it depends on the type of cancer as to how much your dog will be affected health wise. Your veterinarian will do blood tests, x-rays, and a complete physical examination of your dog to determine the extent of the damage.

If your dog is suffering from gastric ulcers, you veterinarian will look at rehydration and fluids depending on the severity of the condition. Dietary changes require a soft, bland diet that is easy to digest, allowing healing to occur. A urinalysis can help detect the virus, and blood work will be done to allow an accurate diagnosis.

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Prevention of Passing Black Stools

While it is hard to prevent every disease or condition that your dog may get,  a good management program covering their health will help. Removing sticks and hard toys that they chew on can prevent any accidents with swallowing sharp pieces. A healthy diet is still the best prevention measure to practice. Speak with your veterinarian to see what is best for your dog. Usually, a wide variety of food that is close as possible to its natural state is best. Keeping your dog fit and just below the average weight is better for their health. Some dogs are better with three small meals rather than one large one, as it minimises the risk of bloating, which can be a dangerous condition.

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Cost of Passing Black Stools

Treatment costs can vary considerably depending on the nature of the illness and what needs to be done to help correct it. Dogs are natural born scavengers and can cause internal injury by eating something that is either sharp or indigestible. The expense for removal of a foreign body and follow-up treatment can average $2500. Bacterial infections can cost on average $1,600. Hemorrhagic gastroenteritis costs from $2000 upwards depending on the severity. Gastrointestinal ulceration can cost up to $2200 for treatment. Cancers can cost $2000 and more. The cost is always related to the degree of the treatment required.

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Passing Black Stools Questions and Advice from Veterinary Professionals

Need pet health advice? Ask a vet

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Pit Bull

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One Year

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Unknown severity

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Diarrhea

He had diarrhea and passed black stool for one day. He also was weak with dilated pupils.

Sept. 29, 2020

Owner

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Dr. Michele K. DVM

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0 Recommendations

Thank you for your question. There are many causes for what you're describing, including a toxin, a GI upset, or an intestinal infection. It would be best to have your pet seen by a veterinarian if this is not improving, as they will be able to examine them and see what is causing this. Once they know more, they will be able to let you know how to treat it. I hope that everything goes well.

yesterday

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German Shepherd

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36 days

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Unknown severity

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Unknown severity

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Tarry Stool

Hi doctor, I have sweet little German shepherd puppy male of 36 days . Before 6 days I buy this puppy and give him ceralac with milk and after that next day he was not eat food when I served him so I take visit to pet doctor he gave him treatment like drip ànd some injection 4 days then after that doctor suggested to sarve him start to give him hills urgent care diet food . We sarve them after that 2 days day I give him but he pass black colour of stool 1 time right now I see can you plz tell me a one time black potty is dangerous. Or we can waite to see next pass of stoole of our puppy

Aug. 7, 2020

Owner

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Dr. Michele K. DVM

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Thank you for your question, I hope your dog is okay. If he just passed that one black stool, it may be caused by some of the medication that he got, and if he seems to be eating and drinking well, he may be okay. Since I'm not completely sure what was going on with him initially, it might be a good idea to call your veterinarian, ask if this is anything to be worried about, and see if he needs other treatments. I hope that all goes well for him.

Aug. 8, 2020

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Labrador Retriever

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Nine Years

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Unknown severity

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5 found helpful

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Unknown severity

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Black Ish Stool

dog had a little bit of black in her stool but is acting completely normal otherwise.

Aug. 6, 2020

Owner

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Jessica N. DVM

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5 Recommendations

Hello- Thank you for your question. With just the single episode I would not be concerned since she is otherwise acting normally. If it happens more frequently, or she starts vomiting, has diarrhea, is lethargic or has a decreased appetite then I would recommend having her seen by your veterinarian so they can perform blood work and abdominal imaging and a fecal to assess what is going on. Have a good evening.

Aug. 6, 2020

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Shih Tzu

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Three Years

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3 found helpful

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Unknown severity

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Vomiting, Lethargy, Red/Black Watery Stool

The stool test has been done, no parasites found. Only a large amount of mucus. Also, the vet gave antibiotics and medicine to stop vomiting. He is no longer vomiting now, but sometimes passing black watery stool.

Aug. 5, 2020

Owner

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Dr. Michele K. DVM

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3 Recommendations

Thank you for your question. If it has not been very long that your dog has been taking the medication, it may take some time to start to work. If you are not sure if it should be working by now, it would be best to call your veterinarian and asked if you should see some improvement by now. It is difficult for me to say as I do not know how long your dog has been on the medication. I hope that all goes well.

Aug. 5, 2020

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American Pit Bull Terrier

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3 months

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Unknown severity

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Black Poop

What should I do he’s been having black poop so far all this morning buts it’s not normal textured

Aug. 4, 2020

Owner

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Dr. Michele K. DVM

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Thank you for your question. Puppies are prone to parasites, and hookworms can be one of those. It would be best to schedule an appointment with your veterinarian as soon as possible, and have an exam for him and have them look at it sequel sample. They will also be able to make sure that he is not showing signs of parvovirus. I hope that all goes well for him.

Aug. 4, 2020

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Benji

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Half Husky half Aspin

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1 Month

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Serious severity

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Serious severity

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Diarrhea
Diarrhea, Vomit, Black Stool, Weak

My dog has a diarrhea for a week. I just found him alone so hungry so I decided to take him home. I thought Its normal because he's still adjusting to the environment but days goes by he's keep on sleeping until he vomits. I gave him Loperamide and I boiled a guava leaves to harden his stool. Someone told me to visit him to vet but there is Covid 19 and Vet Clinic are closed. What should I do? He's very weak but the only thing that makes me happy is he eats so fast. It's just that his diarrhea and stool is black. Please help.

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Bailey

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Pit bull

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10 Years

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Moderate severity

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Black Dry Stool Constipation

Bailey eats ok, is constipated and has black dryish stools, had her to the vet they said pancreatitis, was treated for that, got a little better, but now back to the same, need help

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Blue

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Beagle

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13 Weeks

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Mild severity

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Mild severity

Has Symptoms

My puppy has black, tarry stool. He has no change in his attitude, appetite, or energy. He’s a very happy, active puppy, but I’m worried about his poop color. We have not changed his dog food, and he’s not lethargic at all. He has a vet appointment already scheduled for next week. Should I take him sooner?

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Scrappy

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Chihuahua

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3 Years

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Moderate severity

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Moderate severity

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Dark Bloddy Tarry Stool That Smells
Dark Bloddy Tarry Stool That Smell.

My 3 year old Chihuahua named Scrappy all pf a sudden today started vomitting but was acting normal. As the day has gone on he is lethargic hasnt eaten barely has drank any water. He was just vommitting almost a clear liquid but kind of foamy. Then i found a small pile of mucasy dark red to a brown color that looked like tiny kidney bean sized clots. Then i found 2 small piles of black tarry clots and it smells very bad and im able to smell that same smell on Scrappy. Im trying to hold of taking him to the vet u til the morning because the er vet is very exspensive. Please can someone help me out with this. My dog is my child and im so afraid somethi g bad is going to happen to him.

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Harlow

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Bernese Mountain Dog

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4 Months

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Fair severity

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Fair severity

Has Symptoms

Diarrhea

4 month Bernese ate a large portion of a new, heavy chewer toy and has had very messy, watery diarrhea for 18 hours or so. She's up on shots. Last few seemed dark and possibly a bit red/purple tinged. Not sure if she ate something else. She's otherwise acting normal and she's had two meals of parboiled chicken and plain rice. We're going to call the vet when it opens, but any thoughts are appreciated!

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