Passing Black Stools in Dogs

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
• Clotting disorders
  

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 upper 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. The vet may run some tests such as an abdominal scan ,endoscopy and stool analysis to diagnose an infection. Needless to say, it needs a veterinarian’s intervention and care. 

Hemorrhagic Gastroenteritis or Acute Hemorrhagic Diarrhoea Syndrome

While the cause of hemorrhagic gastroenteritis is currently 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 successful 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, chronic vomiting or diarrhoea, lethargy, loss of appetite or unexplained weight loss then it is advisable to get them to the clinic for a few diagnostic tests.

Clotting Disorders

When a dog's blood does not clot as it should, we can see bleeding from any region, including the upper digestive tract. Clotting disorders can have many causes including rat bait ingestion or Von Willebrand's disease.

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 vet, 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. Some patients will be kept in the hospital for monitoring for several days after.

In the case that your dog is suffering an infectious condition or is battling with parasites, 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, we don't always get a definitive diagnosis as to the cause. To help diagnose the ailment, your dog will require imaging, stool analysis and blood tests. Causes of HGE can include allergic reactions, clostridial infections and toxin ingestion. 

As dogs mature they can be more prone to gastrointestinal 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 a mass is located,  it is usually sampled to determine if it is benign or malignant. A biopsy can be done via an endoscopy, or a biopsy can be surgical (via an exploratory laparotomy). These samples can help provide a diagnosis, enabling the vet to determine the best treatment. 

If your dog is suffering from gastric ulcers, you veterinarian will look at rehydration, ant acid medicine 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. Ulcers can be secondary to underlying disease such as kidney failure, so further tests may be indicated.

While it is hard to prevent every disease or condition that your dog may get,  a good health management program will help. Removing sticks, bones and hard toys that they chew on can prevent any accidents with swallowing sharp pieces. Try to discourage them from drinking out of stagnant bodies of waters and puddles, which can harbour infections. A healthy diet is always advised. Speak with your veterinarian to see what is best for your dog as some will require hypoallergenic diets. Keeping your dog fit and slender is better for their health. 

Keep your dog up to date with their vaccinations and a good quality parasite prevention. 

Black stool can be expensive to treat. If you suspect your dog has black stool or is at risk, start searching for pet insurance today. Brought to you by Pet Insurer, Wag! Wellness lets pet parents compare insurance plans from leading companies like PetPlan and Trupanion. Find the “pawfect” plan for your pet in just a few clicks!

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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 if your dog becomes very unwell and hospitalisation is needed. Hemorrhagic gastroenteritis costs from $2000 upwards depending on the severity. Cancers can cost $2000 and more. The cost is always related to the degree of the treatment required.