Diagnosing Hematochezia and Melena in Dogs: Causes and Treatments 

Hematochezia and Melena are two common gastrointestinal issues that can present in dogs of any age. Therefore, it is essential to recognize the signs of these conditions and identify their causes to provide adequate treatment. This article will discuss the diagnostic process for melena and hematochezia, as well as potential causes and treatments. 

What is Hematochezia? 

Hematochezia describes bloody stool in dogs that have not been digested and appear bright red. It can also indicate gastrointestinal conditions such as ulcerative colitis or hemorrhagic gastroenteritis. However, in contrast to melena, hematochezia does not have an offensive odor.

What is Melena? 

Melena is a medical term used to describe the presence of dark, tarry stools that contain digested blood. The digested blood appears black or dark red, often with an offensive odor. It can signify a variety of gastrointestinal disorders, including ulcers, cancer, and parasitism. 

Diagnostic Process for Melena and Hematochezia 

When diagnosing melena or hematochezia in dogs, it is essential to first take into account the animal’s medical history to rule out any potential underlying causes. It is also necessary to perform a physical examination to assess the patient’s overall health before proceeding with further diagnostic tests. 

The following tests may be conducted when trying to diagnose melena or hematochezia: 

Complete Blood Count (CBC): This test measures the levels of red blood cells, white blood cells, platelets, hemoglobin, and other components, which can indicate if there are any underlying issues related to anemia or infection. 

Biochemical Profile: This test measures enzymes associated with liver and kidney function, which can give insight into any potential organ damage or failure that may be occurring due to melena or hematochezia. 

Urinalysis: This test examines urine for signs of disease, such as urinary tract infections that could potentially be causing melena or hematochezia. 

Radiography: Radiographs provide images of internal organs that can help identify abnormalities such as tumors or obstructions that may be causing melena or hematochezia. 

Endoscopy: This procedure involves inserting an instrument with a camera through the mouth into the stomach to obtain direct visual evidence regarding what may be causing melena or hematochezia.  

Ultrasound Imaging: Ultrasound imaging is used to assess abdominal organs for signs of infection or inflammation which could be causing melena or hematochezia.  

Potential Causes of Melena and Hematochezia 

Once all diagnostic tests have been conducted, it is then possible to determine what may have caused melena or hematochezia in your pet dog. Some possible causes include the following:  

Gastrointestinal Ulcers: Gastrointestinal ulcers are sores caused by an imbalance between stomach acid production and protective mucus production within the stomach lining that can lead to bleeding, which appears as dark-colored stools (melena)  

Cancer: Gastrointestinal cancer can cause bleeding within the digestive tract, which leads to dark-colored stools (melena)  

Parasites: Intestinal parasites such as roundworms, hookworms, whipworms, coccidia, etc., can irritate the digestive tract leading to bloody stools (hematochezia)  

Inflammatory Bowel Disease (IBD): IBD is an immune-mediated disorder caused by chronic inflammation within the digestive tract leading to both dark-colored stools (melena) and bloody stools (hematochezia)   

Treatments for Melana & Hematochezia  

Once a diagnosis has been established regarding what may have caused your pet’s Melana & hematochezia, it is possible to begin treatment depending on what has been found. Some treatment options include:  

Medications: Depending on what was found during diagnosis (ulcers vs. cancer vs. parasites vs. IBD), medications such as antibiotics or anti-inflammatory drugs may be prescribed for your pet to treat their condition  

Diet Modification: If parasites are found during diagnosis, then it may be necessary for your pet’s diet

to be modified to reduce the risk of re-infection. This may include switching to a grain-free or hypoallergenic diet with limited ingredients. 

Surgery: If it is determined that there is a tumor or other abnormal growth in your pet’s gastrointestinal tract, then surgery may be required to remove it.

IV Fluids: If your pet is severely dehydrated due to Melana & hematochezia, they may need to receive intravenous fluids to rehydrate them and restore electrolyte balance. 

Blood Transfusions: Severe blood loss can result in anemia, requiring a blood transfusion for your pet to replenish its red blood cells and restore its oxygen levels. 

Preventing Melana & Hematochezia  

In many cases, the onset of melanoma & hematochezia in your dog can be prevented by taking proper precautions. Some preventative measures that can help reduce the risk of your pet developing melena & hematochezia include: 

Providing Appropriate Nutrition: Ensuring your pet’s diet is balanced and complete with all the essential vitamins, minerals, and nutrients they need will help boost their overall health and make them less prone to developing digestive problems.  

Routine Veterinary Checkups: Making sure that you bring your pet in for regular checkups with their vet will help monitor any changes that occur within their body and allow for early detection of any potential illnesses or diseases that may arise.  

Parasite Prevention: Keeping up with flea and tick prevention and heartworm prevention will help reduce the risk of parasites entering your pet’s system, which could potentially lead to melena & hematochezia if left untreated.  

Monitoring Activity Levels: Making sure that your pet does not overexert themselves during exercise or playtime will help reduce the risk of gastrointestinal issues such as melena & hematochezia from occurring due to physical stress on their body.  


Melena & hematochezia are two common conditions in dogs characterized by bloody stools. It is essential to take these symptoms seriously as they can be caused by various underlying illnesses ranging from minor annoyances such as parasites to more severe conditions such as cancer or tumors. Suppose you notice any signs or symptoms of melena & hematochezia in your dog. In that case, you must bring them to their vet immediately so they can receive an accurate diagnosis and appropriate treatment plan tailored specifically for them. There are also steps you can take at home to reduce the risk of these conditions occurring, such as providing proper nutrition, keeping up with parasite prevention, and monitoring activity levels. With the right preventative measures and timely medical attention, your dog can live a long, happy life without worrying about developing melena & hematochezia!