Cat Vomiting Blood (Hematemesis) – Causes and Treatment

Causes of blood in vomit       Diagnosing the cause      How is it treated?

Hypercalcemia in cats

Vomiting is caused by the forceful ejection of the stomach contents and is a common symptom in cats. More often than not, it contains digested food, but you may also notice vomit which contains bile (a green substance) or blood.

Blood in the vomit (also known as hematemesis) has a number of causes the colour of the blood can provide a clue to the cause.

  • Bright red blood in the vomit indicates the vomit has come from the upper digestive tract (mouth, nose, and esophagus).
  • Dark red with the appearance of coffee grounds means the vomit has come from the lower digestive tract and it has been partially digested.


Blood clotting disorders

  • Liver failure such as portosystemic shunt, hepatic lipidosis or poisoning. The liver is responsible for the production of several clotting factors.
  • Ingestion of certain toxins (rat poison) which inhibit the production of vitamin K which is required for the formation of clotting factors.
  • Low blood platelets (thrombocytopenia).
  • Disseminated intravascular coagulation which may be due to heatstroke, cancer, infection, shock and snake bite.

Ulcers and erosions

  • Ulcers of the esophagus or stomach which may be due to ingestion of substances which erode the lining of the stomach or esophagus, steroids, NSAIDS such as aspirin and Ibuprofen.
  • Ingestion of corrosive substances such as heavy metals or toxins.
  • Mast cell tumours.


  • Foreign body such as a bone which can cause laceration of the intestines or stomach.


  • Gastroenteritis is the inflammation of the stomach and intestinal tract. There are a number of causes including viral, bacterial or protozoal infection.
  • Inflammatory bowel disease – A group of disorders caused by the infiltration of inflammatory cells into the mucosa of the gastrointestinal tract.

Swallowed blood:

  • From the mouth, nose, esophagus or coughed up and swallowed from the lungs.


  • Tumours of the esophagus or stomach.


  • Heartworm or hookworm infection.

Other signs to watch for:

Vomiting, with blood is the obvious symptom, however additional symptoms may occur which can help your veterinarian to narrow down a probable cause. These may include:

  • Loss of appetite
  • Weight loss
  • Black, tarry stools
  • Bleeding from other parts of the body, such as the nose, or mouth
  • Coughing
  • Lethargy
  • Difficulty breathing


A veterinarian should always see a cat who has vomited blood as soon as possible.

He will perform a medical examination of your cat and obtain a medical history from you, including accompanying symptoms you may have noticed and exposure to medications or toxins. Symptoms, along with the type of blood (new or old) can help your veterinarian narrow down a cause.

He will need to perform some medical tests to determine the cause, some of which may include:

  • Complete blood count, urinalysis, and biochemical profile to check the overall health of your cat, look for signs of infection, inflammation, liver function and platelets.
  • Endoscopy – A narrow tube with a light and a camera on the end are inserted into your cat’s digestive tract to look for the presence of tumours, ulcers, and foreign objects.
  • Biopsy of the intestinal tract to look for the presence of inflammatory cells in the intestinal wall.
  • Prothrombin time – To test the blood coagulation rate.
  • Fecal studies to look for the presence of parasites.
  • Ultrasound or x-ray to evaluate for foreign objects, growths and look at the internal organs.


Most cases of vomiting blood will require hospitalisation. Managing the cause of vomiting blood and providing supportive care, which may include intravenous fluids, nutritional support, and anti-vomiting medications.

  • Medicines to reduce stomach acid such as cimetidine, ranitidine or famotidine which prevent further damage and also allows your cat’s GI tract or stomach to heal. Sucralfate is a medication which forms a gel-like consistency in the acidic stomach, covering the ulcers and preventing further damage to the already eroded tissue.
  • Worming medications to treat hookworm.
  • There are no drugs registered for use in cats for heartworm. Treatment is aimed at managing symptoms.
  • Dietary changes and immunosuppressive drugs for cats with inflammatory bowel disease.
  • Antibiotics for bacterial infections and supportive care which may include fluids and switching your cat to a bland diet to rest the GI tract.
  • Surgery to treat tumours or remove foreign bodies.
  • Gastric decontamination (induce vomiting, pumping of the stomach) and administration of activated charcoal to prevent further absorption of ingested toxins.
  • Blood transfusion for severely anemic cats or those suffering from low blood platelets.
  • Determining the cause of liver failure and treating accordingly, this may include dietary changes or surgery.