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Home > Cats > Why Does My Cat Have Blood in His Poop? 15 Vet Reviewed Reasons & What to Do

Why Does My Cat Have Blood in His Poop? 15 Vet Reviewed Reasons & What to Do

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Dr. Paola Cuevas

Veterinarian, MVZ

The information is current and up-to-date in accordance with the latest veterinarian research.

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Spotting blood in cat stool can be alarming. If you ever see blood in your cat’s stool, never ignore it. Reaching out to your vet should be the first step you take.

Since it is frightening to notice blood in your cat’s litter box, you will surely want to know some of the causes of this sign. This list has 15 possible reasons for bloody stools, ranging from mildly concerning to severe. While reading, consider the other signs your cat may be displaying to determine which complications may be the root cause. If your cat has blood in their poop, scroll down to learn more:


The 15 Reasons Why Cats Have Blood in Their Poop:

1. Feline Distemper Virus

Feline Distemper, also known as Feline Panleukopenia, is a highly contagious, life-threatening viral disease in cats. This disease is often fatal and thus is part of the core vaccination schedule of cats. Since the virus has the ability to survive outside of a host, unvaccinated kittens and adult cats are highly susceptible to this infection.

This virus targets the bone marrow, intestinal lining, and other rapidly dividing and growing cells such as fetal tissues, which can cause abortions in pregnant females. Copious watery, bloody diarrhea is characteristic of this infection since the damage to the intestinal tissues causes sloughing of the mucosa.

Unfortunately, there is no specific treatment for feline panleukopenia. Dehydration should be prevented with intravenous fluid therapy, while clinical signs of vomiting and diarrhea are treated with prescription medications. Since the virus attacks the cat’s immune system, antibiotics are often used to prevent secondary bacterial infections. The prognosis for this infection is poor, but a few lucky cats might recover with the support of veterinary treatments. Make sure you vaccinate your cat to prevent this infection.

2. Constipation

Constipation occurs when there is a backup of waste in your cat’s colon, often leading to an inability to use the bathroom. When cats strain to pass the often hardened feces, they may pass blood as a result.

Some causes of constipation include foreign objects getting trapped in the digestive system, hairballs, obesity, lack of exercise, and a narrow pelvic canal. Constipation may also be a sign of idiopathic megacolon.

The cause of constipation will determine the treatment. Drugs or dietary changes may be used to manage the issue, and in more severe cases, surgery may be required.

cat beside litterbox
Image By: Alexandra Morosanu, Shutterstock

3. Diarrhea

Fluid-like feces (also known as diarrhea) is due to quicker movement through the bowels with little water absorption. Rather than being its own condition, diarrhea is a sign of many other complications. Since there are several potential causes, consulting your vet is crucial.

Speaking to a vet is especially important if your cat’s diarrhea comes with bloody excrement. If you notice other signs of general illness, such as lethargy, dehydration, vomiting, and a decreased appetite, you will need to make an appointment with your vet immediately.

4. Intestinal Parasites

Parasites within the gastrointestinal system can cause digestive problems, including bloody cat poop. Parasites are a common issue in cats.

Signs that your cat may struggle with a parasitic infection include coughing, vomiting, diarrhea, a decreased appetite, and an unhealthy coat.

Treatment for parasites will often include prescription medication. Following the instructions on the drug is vital, as improper use can lead to reinfection. The best way to prevent parasitic infections from occurring in the first place is to maintain cleanliness in the home and litter box and keep up to date with deworming schedules.

5. Inflammatory Bowel Disease (IBD)

Inflammatory bowel disease1, also known as IBD, is a reaction to a consistent irritation of the digestive system. When irritated, the digestive system becomes inflamed. This inflammation thickens the gastrointestinal tract and makes it more difficult for your cat to process food and waste.

Often, your cat’s IBD will not have a definite cause. That means it is an idiopathic condition with no known cause. However, if your vet can determine the root of the issue, it will likely be caused by an infection, dysbiosis, stress, or food intolerance. The cause of your cat’s IBD will determine the treatment, which can include deworming, medications, supplements, and dietary changes.

cat in vet clinic
Image By; Andy Gin, Shutterstock

6. Bacterial Infections

Bloody stools can be the result of a bacterial infection. The most common bacterial infection causes are dirty water, tainted dairy, contaminated feces, or undercooked meat. Other signs of your cat fighting a bacterial infection include lethargy, irritability, and a fever.

Typically, vets will treat a bacterial infection with an antibiotic. However, in more severe instances, your vet may use additional treatments. They may include fluid transfusions, especially if your pet is significantly dehydrated.

7. Foreign Object

If your cat has ingested a foreign object, it could lead to bloody feces. Cats are curious creatures who often like to get into things they shouldn’t. If you suspect your cat has eaten something that was never meant to be eaten, look at its signs.

If your cat is experiencing diarrhea, vomiting, lethargy, decreased appetite, difficulty defecating, and pain, there is a good chance that he may have swallowed something. If this is the case, you will need to get your cat to the vet immediately so he can be treated.

8. Cancer

Nobody likes to consider the possibility of cancer, but if there is blood in your cat’s stool, then cancer may be the cause.

The sooner the cancer is diagnosed and treated, the more likely your cat is to have a better quality of life. There are various types of cancer that your cat may experience. The most common cancer in felines is lymphoma, but there is also the possibility of other types. Visiting your vet is the best way to determine your cat’s type of cancer and how to treat it.

Sick cat under the dropper
Image By: Vladimir Gudvin, Shutterstock

9. Toxins

If your cat has ingested something toxic, he may be suffering from bloody stool among other issues. Thankfully, cat poisonings are fairly rare. However, it should not be dismissed as a possibility.

If you believe that your cat has been poisoned, the first step is to ensure the source of the poison is out of reach of other pets or children. Then, you should go to your vet immediately. Common toxins in your home include bleach or other disinfectants, lilies, chocolate, garlic or onions, and weed killers.

10. Stress

Just like with humans, stress can affect cats. If your cat is suffering a lot of mental distress, bloody stools may be a sign of that tension due to constipation or diarrhea.

Other signs include excessive grooming, bathroom use outside the litter box, excessive scratching, constant vocalization, isolation, and aggression. If you notice your cat displaying any or all of these signs, he is likely overwhelmed with something in his environment. The sooner you can find the source of the distress and eliminate it, the sooner his stress levels will return to normal.

11. Poor Reaction to Food

Bloody stools may be an indication that your cat has a food allergy or sensitivity. Food allergies occur when your cat’s immune system is overreacting to an ingredient that he has been previously exposed to.

If you suspect your cat may have a food allergy, pay attention to his skin. Most often, a food allergy will cause itching, overgrooming, scratching, sores, and infections. Other signs include diarrhea and vomiting.

The most common food allergies in cats include beef, fish, and chicken. These allergies can develop anytime, no matter how long your cat has been eating the ingredients without issues. For treatment, the best course of action is to switch to a diet free from the ingredient in question.

cat not eating food
Image Credit: Kitirinya, Shutterstock

12. Trauma

If your cat has suffered an injury around the anus, it is possible that the blood in his poop is from the wound. Other signs that your cat may have an injury include swelling, warmth, pain, discharge, and fever. Your cat may also experience lethargy, vomiting, and diarrhea.

If you suspect that your cat has suffered physical trauma, take them to the vet as soon as possible. Your vet will be able to determine the extent of the damage as well as decide on a proper treatment plan.

13. Colitis or Proctitis

Colitis, inflammation of the colon, or proctitis, inflammation of the rectum, are two potential causes of bloody poop. Two common signs of these conditions include diarrhea and straining to defecate.

There are several possible reasons that colitis or proctitis may develop, which makes it impossible to determine treatment without your vet’s help. If you believe that your cat is suffering from colitis, proctitis, or both, you will need to reach out to your vet as soon as possible.

14. Change in Diet

Changing your cat’s diet must be done with care and patience, or health issues may arise. This is especially important if your cat has been on a single diet for a long time. One of the conditions could be related to the digestive system and is possibly the reason behind your cat’s bloody stool.

Switching cat foods needs to be a gradual process. The full process should take at least a week. If your cat is not picky, it will be easier to change his diet. However, if your cat is an extremely fussy eater, then changing his diet may require much more patience and tact.

a fluffy cat not eating dry food
Image Credit: Popel Arseniy, Shutterstock

15. Kidney Disease

Kidney disease is a serious complication in felines, and it could cause ulcers of the digestive tract, this could be the reason behind your cat’s bloody stools. Usually, the blood is partially digested and has a darker color and coffee-ground appearance. Signs that your cat may have kidney disease include increased thirst, increased urination, dehydration, bad breath, mouth sores, decreased appetite, and weight loss.

This is a condition that must be managed. Managing kidney disease often requires a combination of medications, hydration, and dietary change. Hydration will be a key component of managing this condition, so fresh water must always be available to your cat.


Blood in cat poop can be a worrying sight. We never want to imagine our cats suffering from sickness or pain, but when it becomes a reality, it is important to be informed. If you see bright red blood in cat poop, it’s important to act fast. Once you and your vet can identify the root cause of your cat’s problems, you will be able to pursue treatment that will help your cat return to a happy and healthy life.

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