Blood in Cat's Stool: 13 Vet-Verified Possible Causes

It’s natural to worry if you find blood in your cat’s poop. After all, we’re primed to assume that blood is a sign that something is wrong! The good news is that there are many relatively unserious reasons your cat might have blood in their stools, especially if it is just one time. However, if this is a recurrent occurrence, you will need to investigate further into it.

The Medical Terms

The presence of fresh, red-colored blood in your cat’s stool is referred to as hematochezia. Most pet parents will easily react and know how to refer to this sign. Fresh, red-colored blood in your cat’s stool indicates that the bleeding occurred in the last section of your cat’s gastrointestinal tract, such as in the colon, rectum, or anus.

What many pet parents do not know is that when the cat’s feces are black in color, this is actually due to digested blood. When your cat’s bleeding is in the esophagus, stomach, or small intestine, then the blood is digested giving the feces a black color.

With something like bloody stools, it’s best to have a veterinarian assess your cat’s health. They will have a more comprehensive view of the signs and have the knowledge and experience to help you narrow down the possible causes. Additional diagnostic tests might be required to get a diagnosis and provide your cat with the necessary treatment.

The 13 Reasons Why Your Cat May Have Bloody Poop

1. Anxiety, Stress & Fear

Stress and anxiety can both influence your cat’s stool consistency. Significant life events such as moving house or nearby construction work can negatively impact your cat’s mental state. Have you ever heard the term “gut feeling”? Well, it turns out that the digestive tract and the brain are very interconnected. Anxiety and stress can result in stress-related colitis causing the presence of fresh blood in the cat’s stools.

If you’ve recently undergone significant life changes or a compelling reason why your cat might be more anxious than usual, you can probably write it off as stress-related colitis.¹

However, you should continue to monitor your cat, try to find out what is causing the stress, and remove that factor. If this happens more than once, please let the vet know. It’s better to be safe than sorry.

cat hiding — Image Credit: Mantikorra, Shutterstock

2. Dietary Indiscretion

Suddenly changing your cat’s diet, allowing them to get too many treats, or if they help themselves into something they were not supposed to can also cause them to start pooping blood. Cats are creatures of habit, and if their bodies are suddenly bombarded with unusual amounts or a very different kind of food this could cause them severe gastrointestinal upset as their digestive tract isn’t prepared for the new food composition.

Following gradual food transition guidelines for swapping your cat’s food can help give their digestive system time to adjust to the change. Avoid overfeeding your cat with treats, and remember to keep your food safely stored to prevent any incidents.

3. Foreign Body

Your cat might also experience bloody stool if they ingest something they shouldn’t have. If you suspect that your cat ingested a foreign body a veterinarian best handles these situations as there can be more internal damage than meets the eye.

See if you can determine what your cat might have eaten; inform the vet. Diagnostic imaging tests such as X-rays or ultrasounds might be needed to make a treatment plan. In some cases, cats may require surgical intervention to remove the foreign object from the cat’s gastrointestinal tract.

4. Infection

Gastrointestinal infections can cause your cat to start pooping blood. The treatment and its invasiveness vary by what kind of infection your cat has caught. Feline Distemper is a common cause of bloody stool in kittens and unvaccinated cats.

Kitten_Vaccine — Image Credit: Maria Sbytova, Shutterstock

5. Parasites

Gastric parasites can also cause your cat to start pooping blood. The treatment varies based on the parasite your cat hosts, just like with infections. After checking your cat's fecal sample, the vet will be able to recommend an effective treatment schedule for your cat.

6. Reaction to Medication

Some medications can also cause gastric bleeding. Contact your veterinarian if your cat has recently started taking a new drug, as this could cause your cat’s bathroom woes.

7. Anal Gland Issues

Usually, a cat’s anal sacs are expressed when they defecate, but build-up in the anal glands or other issues in that area can cause your cat to start pooping blood. If your cat has had issues with their anal sacs, please report this to your vet, after checking them they can help you decide the best treatment approach and management plan.

a siamese cat getting examined by a vet at the clinic — Image Credit: Sergey Nivens, Shutterstock

8. Colitis

Inflammation of the large intestine, or colitis, can cause your cat to start pooping blood. This kind of illness can have several different causes and should be seen by a veterinarian familiar with your cat’s typical behavior and diet to ensure that they have a comprehensive view of your cat’s condition.

9. Cancer

Cats with cancer may also start pooping blood, depending on where the tumor is located. If your cat has been pooping blood for a few days and is beginning to decline, you want to check with your veterinarian to rule out cancer as a possible cause for your cat’s troubles.

10. Intoxication

Intoxications are very dangerous and usually occur after a cat consumes a toxic substance, although direct contact and even inhalation are also a possibility. Some toxins cause coagulation problems causing your cat to bleed from the anus, nose, etc. Please note that intoxications are medical emergencies, and time is crucial. The first order of business is to figure out what might be the causing agent. Contact the veterinarian immediately if you are unsure whether your cat has consumed a poisonous substance. It’s better to treat a benign situation as a possible emergency than to treat an emergency as harmless. If the cat was intoxicated the treatment will depend on the kind of toxin they ingested.

black cat gets IV fluids — Image Credit: Anna Krivitskaya, Shutterstock

11. Rectoanal Polyps

Polyps are usually benign, non-cancerous tumors that grow in the mucosal layer of the rectum or the anus of some cats. Straining while defecating or bloody stools are some of the common signs seen on cats with this problem. A definitive diagnosis of this growth is achieved through a colonoscopy and a biopsy needs to be studied to determine the nature of the tumor. In some cases, surgery might be necessary to remove the growth.

12. Constipation & Trauma

Trauma is another possibility if your cat is constipated, the stool becomes dry and hard to pass which might break a vessel in the rectum or anal area.

13. IDB

Inflammatory bowel disease is a multifactorial condition that causes inflammation in the intestinal tract. When the inflammation affects the colon, this can result in bloody diarrhea. This condition can have several causes that range from food sensitivities to stress. Definitive diagnosis requires the examination of biopsies obtained through colonoscopy. Treatment options will likely include dietary management and corticosteroid drugs prescribed by the vet.

My Cat Is Pooping Blood But Has No Other Signs, Are They Okay?

It’s important to remember that cats are exceptionally good at hiding illnesses. This biological defense mechanism prevents them from being picked on by other cats and predators when they’re ill. Look for other more subtle signs of disease when determining whether your cat needs medical attention, like hiding and loss of appetite. However, it is always better to err on caution regarding our cats’ health!

Final Thoughts

It can be scary for your cat to start pooping blood. There are plenty of reasons this might be occurring. If it happens more than once, you should get your cat checked out by a veterinarian to ensure that they aren’t seriously ill, as this sign is present in a wide range of illnesses that range from treatable to deadly. If your cat presents other obvious signs of being unwell and has a very obvious change in behavior, get them checked by the vet soon, it is best to be safe than sorry.