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Black Stool, Tarry Stool (Melena) in cats

Author: Dr. med. vet. Gisa Löwe | Last modified: 17.02.2026

When to visit the vet?

Emergency see a veterinarian immediately

If the condition worsens / symptoms persist, consult a veterinarian.

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Definition of

The term “melena” refers to the occurrence of black, tarry stool in cats. This symptom indicates the presence of digested blood in the stool, often suggesting bleeding in the upper gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. tract.

Can Occur with the Following Diseases:

Grundlagen und mögliche Ursachen

Melena occurs when blood from the upper gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. tract, particularly from the esophagusThe esophagus is a muscular tube that connects the pharynx to the stomach. It transports food from the mouth to the stomach through rhythmic contractions (peristalsis)., stomach, or upper small intestineThe intestine is the medical term for the gut, including the small intestine (intestinum tenue) and the large intestine (intestinum crassum). It plays a central role in the digestion and absorption of nutrients., is digested. The digestive enzymesEnzymes are biological catalysts that accelerate specific chemical reactions in the body without being consumed. They play a crucial role in virtually all physiological processes. and stomach acid change the color of the blood, giving the stool its characteristic black color. The term “tarry” describes not only the color but also the consistency of the stool, which often appears sticky and shiny.

There are numerous potential causes for melena in cats. A common cause is stomach ulcers or duodenal ulcers, which can be caused by medications such as nonsteroidal anti-inflammatory drugsAnti-inflammatory drugs are medications that reduce inflammation. They can be divided into nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids and are used in dogs and cats to reduce Inflammatory conditions and Pain. (NSAIDsNSAID (non-steroidal anti-inflammatory drug) stands for non-steroidal anti-inflammatory drugs, a class of medications used to relieve pain, reduce inflammatory conditions, and lower fever without using steroidal agents. They are a commonly used pain reliever in veterinary medicine.) or stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being.. Tumors in the gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. tract, such as adenocarcinomas or lymphomas, can also cause bleeding. Infections, especially with bacteriaBacteria are microscopic, single-celled organisms that exist in almost every environment on Earth. Some types of bacteria are beneficial or even essential to life, while others can cause disease. such as Helicobacter, can also play a role.

Another possible cause is a blood coagulationBlood coagulation is a process that helps stop Bleeding when a blood vessel is damaged. Platelets and certain proteins in the plasma form a blood clot that seals the wound. disorder, which can be triggered by liver diseases, poisoning, or genetic defects. If the blood does not clot properly, even minor injuries in the gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. tract can lead to significant bleeding. Traumas, such as swallowing foreign objects, can also lead to injuries and bleeding.

Typische Begleitsymptome

Pale gums: Blood loss can lead to anemia, which is recognizable by pale or whitish gums. This is a sign that the cat may not be getting enough oxygen.
Vomiting: Bleeding in the stomach can cause Vomiting, which often looks dark or like coffee grounds, indicating digested blood.
Loss of appetite: A cat with gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. discomfort or Pain from ulcers will often refuse to eat.
Weight loss: If the cat eats little or nothing over a long period of time, this can lead to significant Weight loss.
Weakness or lethargy: Due to the Blood loss and anemia, the cat may appear weak and lethargic because the body is not getting enough oxygen.
AbdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. pain: The cat may show signs of discomfort or Pain in the abdomenThe abdomen, also known as the abdominal cavity, is the part of the body located between the rib cage and the pelvis. It houses several important organs, including the stomach, liver, kidneys, intestines, and spleen., such as increased meowing, withdrawal, or Sensitivity to touch.

Wann zum Tierarzt?

Eskalation: — (Base is RED). Immediate consultation: Indicates upper GI bleeding (stomach/small ) or severe causes of bleeding.

An immediate visit to the veterinarian is necessary if melena occurs, as this may indicate a potentially life-threatening situation. It is particularly urgent if the cat also shows symptoms such as vomiting, pale gums, or extreme weakness. These signs indicate significant blood loss or a serious underlying condition.

Even if melena is the only symptom, the pet owner should not hesitate to consult the veterinarian, as the underlying cause is often serious and difficult to determine without expert diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients.. The sooner the cause is identified and treated, the better the chances of a full recovery.

Symptomerkennung für den Tierhalter und tierärztliches diagnostisches Vorgehen

It is important for the pet owner to observe the cat’s stool regularly. Black, tarry stool is a clear sign of melena. Changes in the cat’s behavior, such as reduced activity or loss of appetite, should also be taken seriously.

The diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. begins with a thorough medical historyThe medical history is the systematic collection of a patient's medical history through questioning. It includes information about previous illnesses, treatments, allergies, and lifestyle habits. and physical examination by the veterinarian. Blood tests are essential to determine signs of anemia or coagulationCoagulation is the process of blood coagulation, in which liquid blood is transformed into a solid clot. This process is crucial for stopping Bleeding and promoting wound healing. disorders. A stool examination can also be performed to detect blood in the stool. Further investigations may include an ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. or X-rayX-ray is an imaging technique that uses X-rays to create images of the inside of the body. It is often used to diagnose bone fractures, lung diseases, and other conditions. of the abdomenThe abdomen, also known as the abdominal cavity, is the part of the body located between the rib cage and the pelvis. It houses several important organs, including the stomach, liver, kidneys, intestines, and spleen. to identify tumors or abnormalities.

In some cases, an endoscopy is required to examine the gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. tract directly and possibly take tissue samples for biopsyA biopsy is a medical procedure in which a small amount of tissue is removed from the body to be examined under a microscope for signs of disease. Biopsies can help diagnose cancer and other conditions.. These procedures help to determine the exact cause of the bleeding and to plan a specific treatment.

Was kann der Tierhalter tun und professionelle Therapieoptionen

As a pet owner, you can take some measures to make the situation easier for your cat while waiting for the appointment with the veterinarian. Make sure the cat has access to fresh water to avoid dehydration, especially if it is vomiting or has diarrheaDiarrhea refers to the condition of frequent, watery bowel movements, which can be a sign of infections, digestive disorders, or other health problems..

It is important to calm the cat and keep it in a quiet environment to minimize stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being., which could worsen the situation. Avoid giving the cat medication without veterinary advice, as this could worsen the situation, especially if stomach ulcers or blood coagulationBlood coagulation is a process that helps stop Bleeding when a blood vessel is damaged. Platelets and certain proteins in the plasma form a blood clot that seals the wound. disorders are suspected.

Feed the cat easily digestible food if it is willing to eat, so as not to put additional strain on the gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. tract. Some veterinarians recommend specific diets or feeds that are suitable for cats with gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. problems, and it may be helpful to consider these.

Collaboration with the veterinarian is crucial to developing the best treatment strategy for your cat and successfully treating the cause of the melena. Depending on the diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients., medication, surgical intervention, or a special diet may be necessary to restore your cat’s health.

Ausblick auf aktuelle Forschung

Research on melena in cats is currently focused on improving diagnostic methods to identify the exact source of gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. bleeding. One of the latest developments is the use of endoscopyEndoscopy is a diagnostic procedure that uses an endoscope (a thin, flexible tube with a light source and a camera at the end) to examine and visualize the inside of the body, often for diagnostic or therapeutic purposes. and minimally invasiveInvasive describes medical procedures or pathogens that enter the body or penetrate tissue. In medicine, invasive procedures can range from minimally invasive techniques to open surgery. imaging, which allows for detailed examination of the digestive tract without the need for invasiveInvasive describes medical procedures or pathogens that enter the body or penetrate tissue. In medicine, invasive procedures can range from minimally invasive techniques to open surgery. surgical procedures. These technologies help to determine the location of the bleeding more accurately and thus develop more targeted treatment strategies.

Another area of research is the development of specific biomarkers in the blood that can indicate whether melena is triggered by an infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease., an ulcerAn ulcer is an open wound or erosion of the skin or mucous membrane that often heals poorly and can be caused by a variety of factors, including infections and chronic inflammatory conditions., or another cause. By identifying such biomarkers, early diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. could be facilitated and personalized therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. developed. This biomarker research is particularly important because it could help avoid unnecessary treatments and improve the quality of life of affected animals.

Current research is also investigating the role of nutrition in the preventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring. and treatment of melena. Scientists are exploring how certain dietary changes can help improve the health of the gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. tract and reduce the risk of internal bleeding. For example, the effect of fiber and probiotics on intestinalIntestinal refers to the intestine, the part of the digestive tract that extends from the stomach to the anus. Intestinal diseases affect the small and/or large intestine. health is being studied to determine whether they have a protective effect.

Genetic research is also an emerging field with regard to melena in cats. Researchers are analyzing genetic predispositions that could make certain cat breeds more susceptible to gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. problems. A better understanding of these genetic factors could, in the long term, lead to breeding healthier cats and reducing the incidenceIncidence refers to the number of new cases of a disease or condition that occur within a specific time period in a specific population group. It provides information about the risk of contracting the disease. of melena.

Finally, intensive research is being conducted in the field of treatment methods, particularly with regard to the development of new drugs that can accelerate the healing of gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. mucosal lesions. Research on drugs that promote blood coagulationBlood coagulation is a process that helps stop Bleeding when a blood vessel is damaged. Platelets and certain proteins in the plasma form a blood clot that seals the wound. or regulate stomach acid production could open up new avenues for effectively combating melena.

Häufig gestellte Fragen

What is melena in cats? Melena is the medical term for black, tarry stool, which indicates digested blood in the stool. It is a symptom that can indicate bleeding in the upper gastrointestinal tract of a cat.
What does melena look like? Melena appears as shiny, black or very dark stool that has a tarry consistency. The odor can be particularly strong and unpleasant.
What are the most common causes of melena in cats? The most common causes include stomach ulcers, tumors, the use of certain medications such as NSAIDs, and severe infections or inflammatory conditions in the gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. tract.
How is melena diagnosed in cats? The diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. is usually made through a combination of physical examination, blood tests, imaging procedures such as X-ray or ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow., and possibly an endoscopyEndoscopy is a diagnostic procedure that uses an endoscope (a thin, flexible tube with a light source and a camera at the end) to examine and visualize the inside of the body, often for diagnostic or therapeutic purposes. to identify the source of the bleeding.
Can melena in cats disappear on its own? Melena usually requires veterinary treatment, as it is a sign of internal Bleeding that will not heal on its own without appropriate medical intervention.
Is melena life-threatening in cats? Yes, melena can be life-threatening, especially if it is caused by serious conditions such as stomach ulcers or tumors. Rapid diagnostic clarification and treatment are crucial.
What treatment options are there for melena in cats? Treatment may include medications to reduce stomach acid, promote blood coagulationBlood coagulation is a process that helps stop Bleeding when a blood vessel is damaged. Platelets and certain proteins in the plasma form a blood clot that seals the wound., or treat the underlying cause of the bleeding. In some cases, surgery may be necessary.
How can I prevent my cat from developing melena? Regular veterinary examinations, a balanced diet, and the careful use of medications can help reduce the risk of melena. It is important to avoid known risk factors.
How quickly should I act if my cat has melena? It is important to see a veterinarian immediately if you notice melena in your cat in order to determine the cause and begin appropriate treatment.
Can melena be a sign of cancerCancer refers to the uncontrolled proliferation of cells that can lead to tumors or spread throughout the body. Various types of cancer occur in dogs and cats, ranging from skin cancer to lymphomas. in cats? Yes, melena can indicate cancerCancer refers to the uncontrolled proliferation of cells that can lead to tumors or spread throughout the body. Various types of cancer occur in dogs and cats, ranging from skin cancer to lymphomas. in the gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. tract, such as stomach or intestinalIntestinal refers to the intestine, the part of the digestive tract that extends from the stomach to the anus. Intestinal diseases affect the small and/or large intestine. tumors. A thorough veterinary examination is necessary to confirm or rule this out.