What Causes Blood in Cats' Stool?

Adrienne is a certified dog trainer, behavior consultant, former veterinarian assistant, and author of "Brain Training for Dogs."

Upon noticing blood in their cat's stool, many pet owners become concerned that their cat may have cancer. However, it may be reassuring for cat owners to learn that blood in their pet's stool is usually caused by something less serious.

Common Causes of Blood in Cats' Stool

  • Injury: In order to locate possible injuries, the cat's rectal area, including the anal sac area, should be inspected carefully. Sometimes, the passage of dry stools may cause limited bleeding. In some cases, the ingestion of sharp bones may scrape on the lower intestine or rectal area as they pass. This causes a small amount of bleeding.
  • Parasites: Cats may be affected by various parasites and protozoans that may cause irritated bowels and blood in the stool. Roundworms, hookworms, coccidia are often the culprits. A fecal test will be able to detect them.
  • Rectal Polyps: These are benign masses that present in the rectal area. They tend to be highly vascularized. This causes them to bleed easily when the feces passes through the rectum.
  • Dietary Intolerance: Foods that cause allergies, sudden diet changes, intolerance, or other complications that may irritate the lower bowels, may eventually cause blood in the stools.
  • Rat Poison Ingestion: Rat poison is meant to cause rodents to bleed to death. If a cat indirectly eats a poisoned rat, or if the cat directly eats some rat poison, it will interfere with the cat's blood clotting system. This causes spontaneous bleeding from the rectum, mouth, nose, or under the skin.
  • Blood Clotting Disorders: In this case, the cat may be affected by a disorder that interferes with the proper clotting of the blood. In this case, the cat will bleed. Sometimes this is spontaneous, or it can occur with a minimum amount of trauma.
  • Cancer: While not very common, cancer is always a possibility and should be ruled out—especially when dealing with senior pets.

Where Does the Blood Come From in Stools?

First of all, it is important to learn about where the blood is deriving from. As a general rule, fresh red blood (medically known as hematochezia) usually derives from either the lower intestines, or the rectum.

It is very important to find out if the blood is actually coming from the rectum and not from the urethra. Cats, at times, may suffer from urinary tract infections where they may strain to urinate. These infections produce bloody drops of urine. In this case, if the cat is a male, the risks of a urinary blockage are high and life-threatening. If this is the case, then the cat may require immediate veterinary treatment.

On the other side of the spectrum, the presence of black, tarry, blood (medically known as melena) derives most likely from the upper intestinal tract and stomach. In this case, the dark color derives from digested blood. This is often seen in cats suffering from bleeding stomach ulcers.

As you can see, there are various causes of blood in a cat's stools. If the bleeding episode is a one-time ordeal with minimal bleeding and the cat is bright and alert, very likely it may be something minor that will not continue to persist. However, if the cat has a lot of blood loss, exhibits pale gums (suggesting anemia) and the bleeding episodes continue, a prompt vet visit is highly recommended.

If your cat has bloody stools, please consult with a veterinarian for a hands-on examination.

© 2009 Adrienne Farricelli

Alex on November 26, 2017:

I think this site is really good helpful and even interesting

Adrienne Farricelli (author) on May 27, 2012:

Thanks a bunch! All the time I worked for my vet never encountered a case with Spirocerca Lupi, maybe it is more common in certain areas than others? quite interesting, looking this parasite up...

Joe Njenga from Nairobi Kenya on May 27, 2012:


I think parasitism and poisoning are the highest on the list of the causes of blood in the cat's stool. You should also ensure you look at the nature of the blood in the feces since it may be helpful for identifying the cause. Example: Blood in feces that seems to have gone through the entire GIT would be more likely come from the upper GIT. In dogs, the Upper GIT may at times be infected by a notorious worm Spirocerca Lupi. All the same your hub is comprehensive and well written, thanks

Kathy from The beautiful Napa Valley, California on January 24, 2011:

Thank you, alexadry, for this really informative hub. You've answered several of my concerns, keeping in mind the caveat you've included at the conclusion of this article. I appreciate your indepth discussion about this condition; and all the possibilities listed are, indeed, useful to know...and, yes, of course, one should consult a Veterinarian when / if there is doubt. Great article! Thank you!


  • Slippery elm: A herbal remedy which has many medical uses. It contains mucilage (a gelatinous substance) which coats and soothes the intestines and stomach as well as increasing mucus secretion which protects the gastrointestinal tract.
  • Probiotics: Yoghurt contains a type of bacteria known as lactobacillus these bacteria usually reside in the intestines, helping with the digestion of food. Sometimes the natural flora of the gut is thrown out of balance (for example if your cat is on a course of antibiotics), and this can lead to opportunistic and pathogenic strains of bacteria taking hold.

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Julia Wilson

Julia Wilson is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. She enjoys photography, gardening and running in her spare time. Full author bio Contact Julia

When does Megacolon Occur?

The accumulation of compact fecal depostis in the colon that are unable to push through to the rectum. Depending on the dehydration level of the cat, it may experience constipation.

Consistent constipation that is immune to medication may lead to obstipation where there is a loss of rectal function.

Obstipation may be too severe that it causes the colon to enlarged and stretched. The stretching may even be up to three to four times the normal size.

With an enlarged colon, the colon muscles are not able to contract thus don’t release the waste blocking the waste and gas passage this may be deadly fatal.

What should you do If your cat has a bloody stool?

If you find blood in your cat’s stool, contact your veterinarian. It can be caused by a small problem, such as constipation or hard stools, but it’s a good idea to get an examination by a vet. Your vet may perform blood and physical tests to discover the problem of your cat’s bloody stool. He also completely examined the rectum. He may also perform imaging methods to look at the colon in more detail.

Treatment of stool blood generally depends on the actual blood cause. If no acute illness is found, your veterinarian may recommend gastrointestinal support medications and supplements. This may include probiotic use over a period of time. Dietary changes may also be required.

How to Treat a Cat with Blood in Its Stool

Checking out your kitty’s litter tray might not be the most glamorous task, but it’s a quick and easy way to keep an eye on their digestive health. Changes in frequency, consistency, color and odor can indicate a problem, and act as a surprisingly effective health indicator.

One common problem you might see is blood in the stool. Although this might seem worrying, the symptom can be triggered by a variety of health conditions, many of which are easily treatable.

To help you work out why there might be blood in your cat’s stool, and what you should do about it, read on. Below, we run through some regular causes of bloody stool, different variations of the symptom, and what owners should do about it.

Watch the video: Colitis: Mucus and red blood in stool (July 2021).