Anal & Rectal Bleeding In Cats-Causes, Symptoms & Treatment

Causes   Additional symptoms   Diagnosis


Anal bleeding in cats

At a glance:

About: Anal and rectal bleeding refers to blood from the anus, the rectum or is on the inside or outside of the feces. There are a number of causes including constipation, impacted or infected anal glands, anal abscess, polyps, cancer, inflammation and internal bleeding due to blood clotting disorders.

Symptoms: Depending on the underlying cause, but you may notice blood on the outside of the feces or within it, straining to go to the toilet, pain when defecating, anal scooting, hard, dry stools or diarrhea and pale gums.

Diagnosis: Physical examination and medical history, accompanying symptoms and diagnostic tests which may include colonoscopy, medical imaging, routine blood and fecal studies.

Treatment: This depends on the underlying cause but may include surgery, stool softeners, anti-worming medications, antibiotics and dietary changes.


Anal and rectal bleeding refers to blood which may be noticed on or around the anus,  the opening at the end of the cat’s digestive tract, its function is to pass feces out of the body,  or the rectum, which is the final section of the large intestine, inside your cat.

You may notice bright red blood on the anus, especially after a bowel movement, but more commonly blood is seen on or in the feces.


Blood can originate internally, from the stomach and intestines (colon, rectum, anal canal) or externally, from the anus or the anal glands.

Impacted anal glands

Located at the 5 and 7 o’clock position on the cat’s anus, the anal glands contain a thick, foul-smelling substance which is released from the glands when the cat defecates. From time to time, the substance in the glands can become thick, causing impaction and inflammation. Eventually, the glands will abscess and possibly rupture.


Pain when defecating and the presence of blood in the feces or around the anus and an unpleasant smell.


Empty the glands and pack with antibiotic ointment. Your cat may need to go on a course of antibiotics. If the problem is recurrent, surgical removal of the glands may be necessary.


From time to time, your cat may experience difficulty emptying his bowels. When this occurs, the feces can become dry and hardened. Constipation can develop in senior cats, cats who are dehydrated, cats on a low fibre diet, dirty litter trays which lead to holding onto the feces for longer than necessary, pelvic injury or abnormality, hypothyroidism and neurological disorders. Small tears can occur in the rectum when a constipated cat passes a stool.


Crying in the litter tray, passing small amounts of feces, or straining to defecate.


Switch to high fibre diet or add fibre to the diet. Encourage water consumption by feeding a wet diet, providing more water bowls, or buying a water fountain, and in severely constipated cases, stool softeners or enema.

Rectoanal polyps

These types of polyps are uncommon in cats. Polyps are noncancerous nodular growths in the rectum or anus.


Straining to defecate, blood in the stool and occasionally you may see a polyp protruding from the anus.


Surgical removal of the polyps. They may return at a later date, requiring additional surgery.

Hookworm infection

Hookworms are small, thin nematodes that are approximately 10 to 20 mm in length and are a common intestinal parasitic worm of dogs but can also infect cats. They live in the duodenum, the first part of the small intestine, where they attach themselves to the mucous membrane using teeth-like hooks to feed on the
blood. Worms change their point of attachment every 4-6 hours, which causes the area to bleed.  Blood loss due to the can lead to anemia, intestinal bleeding, intestinal inflammation, diarrhea and even death.Symptoms: Bloody stools which are often running, pale gums (due to anemia), and stunted growth in kittens.


Anti-parasitic medication to kill the worms.

Inflammatory bowel disease

Inflammatory bowel disease is a group of disorders caused by the infiltration of inflammatory cells (white blood cells) in the mucosa of the gastrointestinaltract. It can affect both the upper and lower intestinal tract.


Chronic vomiting and diarrhea, sometimes with blood in it.


Management of these conditions with a highly digestible diet, immunosuppressive therapy, and antibiotics when needed.


Also referred to as malignant neoplasms or malignant tumours, cancer is the uncontrolled division of cells that normally should be restrictive in their growth. Cancers which can develop anywhere along the intestinal tract and rectum can lead to bleeding. There are several types of cancer which can form depending on the originating cell line, which include mast cell tumour, lymphoma, adenocarcinoma, gastrointestinal stromal tumour, leiomyosarcoma, submucosal carcinomas, plasma cell tumour and hemangiosarcoma.


Weight loss, vomiting, bloody diarrhea, anorexia, lethargy and abdominal mass.


Surgery to remove the growth if possible, chemotherapy or radiotherapy to shrink the tumour, slow down tumour growth or kill any remaining cells.


Inflammation of the lining of the colon (large intestine) which have a number of causes including infection, stress, dietary, parasites or cancer.


Diarrhea, which may contain blood, frequent passage of watery stools, reduced appetite.


The goal of treatment is to address the underlying cause. Severely affected cats will require hospitalisation and fluids. Food may be withheld for 24 hours to rest the colon. High fibre diet to increase stool bulk, anti-inflammatory medications. If scar tissue has developed, surgery will be necessary.


Inflammation of the intestines, most commonly due to bacterial infections from salmonella, cryptosporidium, and E-coli.


Vomiting, diarrhea, lethargy, loss of appetite and dehydration.


Antibiotics to kill the bacteria and supportive care such as fluids to treat dehydration and nutritional support. It may be necessary to feed a bland diet for several to rest the gastrointestinal tract.

Blood clotting disorders

Blood clotting disorders (coagulopathy) affect the ability of the blood to form clots which are essential for preventing excessive bleeding when a blood vessel is injured. Clotting disorders can involve the platelets (thrombocytopenia), coagulation factors (which cause hemophilia).

  • Most cases of hemophilia are inherited, but liver disease, aspirin poisoning, and rodenticide poisoning can also cause blood clotting disorders.
  • Thrombocytopenia has a number of causes including leukemia, myelodysplasia syndrome, viral infections, immune-mediated destruction of platelets.


Blood in the urine or stool, red spots on the gums, nosebleed, pale gums due to anemia.


Find and treat the underlying cause if possible. Whole blood or plasma transfusions may be necessary to maintain normal blood cell counts and administration of vitamin K.

Accompanying symptoms:

Blood may be seen on and around the anus, on the outside of the feces or throughout the feces. Other symptoms vary depending on the underlying cause but may include:

  • Anal scooting – Dragging the bottom along the floor.
  • Difficulty defecating – Spending longer than normal in the litter tray or defecating outside the litter tray.
  • Painful defecation – Crying in the litter tray or defecating outside the tray due to associating the litter box with pain.
  • Swelling around the anus – Due to impacted anal glands or an anal gland abscess.
  • Mucus in the stool – From inflammation or infection.
  • Diarrhea – Loose, watery stools.
  • Blood in the urine – Due to internal bleeding caused by blood clotting disorders.

Generalised symptoms:


Your veterinarian will perform a complete physical examination of your cat and obtain a medical history from you. Depending on presenting symptoms, he will want to run some diagnostic tests to determine a cause. Tests may include:

  • Baseline tests – Complete blood count, biochemical profile, and urinalysis to evaluate organ function, check for signs of inflammation. Cats with thrombocytopenia will have low blood platelets and anemia may be present in cats who have severe hookworm infection.
  • X-Ray or ultrasound – To look at the GI tract for tumours or polyps.
  • Colonoscopy – This procedure involves insertion of a fine tube with a camera at the end to evaluate the colon for signs of inflammation, polyps, and/or cancer. Biopsies may be taken at this time which will be evaluated.
  • Blood clotting tests – Such as coagulation assays, prothrombin time, activated partial thromboplastin time and thrombin time to evaluate the blood’s ability to clot.
  • Bone marrow biopsy – To determine the cause of low blood platelets.

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