Blood in Cat Stool

Jennifer Coates, DVM
Written by:
Published: August 22, 2022
Blood in Cat Stool

Having to scoop the litter box certainly isn’t fun, but it does give you an easy way to monitor your cat’s health. Unless there’s been a recent change in diet, your cat’s stool should look fairly consistent from one day to the next. Normal cat stool should be somewhat firm or formed, brown or dark brown, and not runny or extremely foul-smelling.

Pay attention when you notice something out of the ordinary, as it may be the first sign of a health problem. This is especially true when you see blood in your cat’s stool.

What Does Bloody Poop in Cats Look Like?

Blood in cat poop can differ in appearance, depending on which area of your cat’s body it’s coming from, how much is present, and the stool consistency.

  • Black poop (melena) – When bleeding occurs early in the digestive tract (the mouth, esophagus, stomach, and small intestine), the blood gets partially digested by the time it appears in a cat’s stool, making it look black and tarry.

  • Bright red blood in poop – The presence of bright red blood in your cat’s poop means that something is wrong toward the end of their digestive tract—specifically the large intestine, rectum, or anal area.

  • Bright red blood in diarrhea – When a cat has bright red blood in diarrhea, the underlying problem (or the diarrhea itself) has damaged the blood vessels in the cat’s large intestine, rectum, or anus.

  • Bright red blood coming from the cat’s anus – Blood may come directly from a cat’s anus with diseases or injuries affecting the rectum, anus, or surrounding structures (anal glands, for example).

  • Blood and mucus in poop – The lining of the large intestine often secretes more mucus than normal to try to protect itself from irritation.

  • Watery blood – In extreme cases of bloody diarrhea, a cat’s stool may look like water mixed with blood.

  • Blood clots in poop – If there is enough blood in a cat’s lower digestive tract, it may clot and look dark red and somewhat like gelatin.

How Serious Is Blood in a Cat’s Stool?

Never ignore blood in your cat’s stool. Assess your cat’s overall well-being to determine if you are dealing with a potential emergency. If any of the following apply, call a veterinarian to schedule an immediate appointment:

  • A lot of blood in the stool

  • Pale, blue, or deep red gums

  • Repeated vomiting

  • Severe diarrhea

  • Pain

  • Weakness

  • A lack of energy

  • Your cat is very young, very old, pregnant, or has an underlying health problem

On the other hand, cats who have just pooped a tiny amount of blood but seem to feel fine don’t need to be rushed to the nearest emergency clinic. Keep a close eye on the litter box and watch for any new symptoms. If you continue to see blood or your cat starts acting sick, make an appointment with your veterinarian.

What Causes Bloody Poop in Cats?

There are many possible causes of bloody poop in cats:

  • Diarrhea – Any underlying issue that causes severe or chronic diarrhea can irritate the lining of the intestines and cause bleeding.

  • Constipation – Hard stools can scrape against and damage blood vessels, resulting in bleeding.

  • Intestinal Parasites – Some types of intestinal parasites, like hookworms, Giardia, and coccidia, can lead to bleeding in the digestive tract.

  • Organ Dysfunction – Cats with organ dysfunction commonly develop diarrhea. Kidney disease may also lead to ulcers that cause bleeding in the digestive tract, and liver disease sometimes results in abnormal blood clotting.

  • Inflammatory Bowel Disease (IBD) – The inflammation associated with IBD can get severe enough that the lining of the digestive tract bleeds.

  • Bacterial, Viral, and Fungal Infections – Infections affecting the gastrointestinal tract, like panleukopenia and salmonellosis, can result in bleeding.

  • Foreign Bodies – Bones and other foreign materials that a cat might swallow can damage the digestive tract.

  • Cancer and GrowthsBenign growths and malignant cancers of the digestive tract may bleed. Sometimes cancer outside the digestive tract, such as mast cell tumors, can cause gastrointestinal bleeding.

  • Toxins – Ingestion of caustic materials can erode the lining of the gastrointestinal tract. Anti-coagulant rodenticides, for example, can prevent blood from clotting normally.

  • Drugs – Nonsteroidal anti-inflammatories and corticosteroids can cause gastrointestinal ulcers and affect blood clotting, particularly in cases of overdosage.

  • Stress – Cats who are stressed can develop diarrhea, and in severe cases blood may be present.

  • Adverse Food Reactions – Food intolerances, food allergies, or simply switching to a new food can lead to diarrhea, which may or may not contain blood.

  • Trauma – Surgery or injury in the digestive tract can result in blood in the stool.

How Do Vets Diagnose Bloody Poop in Cats?

Veterinarians usually start the diagnostic process for bloody poop in cats by asking a series of questions. Your answers will help the doctor identify which tests to run first. Be prepared to provide information about the following:

  • Your cat’s health history, including illnesses, injuries, surgeries, medications, and supplements.

  • Your cat’s lifestyle, including outdoor access, current diet, dietary changes, and stressful events.

  • The bloody poop itself. Did it just start, or has it been a problem for a while? What other symptoms have you noticed? Is more than one animal in your home affected?

Then, the vet will perform a physical examination and likely run a fecal examination to identify any parasites or bacteria that might be involved. Whenever possible, bring a fresh stool sample from home with you.

Additional diagnostic testing will be necessary if the cause of a cat’s bloody poop still can’t be identified. A veterinarian might recommend a complete blood cell count, blood chemistry panel, urinalyses, specialized laboratory tests, x-rays, an ultrasound exam, endoscopy, surgery, or tissue biopsies.

How Do Vets Treat Cats With Blood in Their Stool?

Cats who have lost a lot of blood sometimes need quick treatment to stabilize their condition. A veterinarian may immediately start intravenous fluids or even a blood transfusion.

Treatment will then be focused on your cat’s underlying health problems. A veterinarian may prescribe medications to get rid of intestinal parasites, antibiotics to address bacterial infections, or stool softeners to relieve constipation. Surgery or endoscopy may be needed to stop bleeding or remove foreign bodies or tumors.

Symptomatic treatment is also sometimes necessary. For example, a cat with severe diarrhea may need anti-diarrheal medications while other treatments start to take effect. Probiotics can help normalize a cat’s gut microbiome and lessen diarrhea.

Your veterinarian may also recommend a change in diet—high-fiber, low-fiber, or hypoallergenic foods could all be appropriate, depending on your cat’s diagnosis.

Ultimately, a veterinarian who is familiar with the specifics of your cat’s case is in the best position to recommend appropriate treatment. Don’t wait to get your cat the care they need.

Featured Image: iStock.com/Tomwang112


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