Veterinarian explains: Causes and treatments of bloody stools in cats, and how to identify dangerous symptoms

When abnormalities occur in a cat's gastrointestinal tract, bleeding can lead to blood in the stool, a condition known as bloody stool (hematochezia/melena). Depending on the site of the bleeding, the stool may appear black or contain bright red blood.

In this article, we will explain bloody stool in cats in detail.

What is bloody stool in cats? Checking the difference from normal stool

Types of bloody stool

Normal stool is light to dark brown. While bloody stool is caused by bleeding in the digestive tract, the color changes depending on where the bleeding occurs.

If it is black, it indicates bleeding in the upper gastrointestinal tract, such as the mouth, nose, stomach, or duodenum. The blood turns black as it passes through the intestines, resulting in melena (black, tarry stool).

If it contains bright red blood, it indicates bleeding in the digestive tract from the large intestine to the anus. Bleeding in the first half of the large intestine causes blood to mix into the stool, while bleeding in the latter half or from the anus leaves blood on the surface of the stool.

Other signs of abnormality that appear with bloody stool

Bloody stool is caused by inflammation, lesions, or tumors. Therefore, other symptoms such as pain, loss of appetite, vomiting, and diarrhea may also occur. While symptoms vary depending on the cause, bloody stool itself is not something to simply wait and see.

Major causes of bloody stool in cats

Dietary and digestive system issues

Dietary issues can sometimes be the cause of bloody stool. If a cat with an allergy consumes a triggering food, it can develop allergic gastroenteritis, leading to diarrhea, vomiting, or bloody stool. In addition to gastrointestinal symptoms, systemic itching and hair loss may also occur.

Additionally, ingesting onions, houseplants, or medications can lead to bloody stool.

A major cause of bloody stool is inflammation of the digestive tract, such as gastritis, enteritis, or colitis. These inflammations are caused by viral or bacterial infections, allergies, immune disorders, or medications. Bloody stool due to digestive tract inflammation is accompanied by various symptoms, including vomiting, diarrhea, loss of appetite, and lethargy.

If a tumor forms in the digestive tract, it may bleed continuously, causing bloody stool. Tumors are fragile and have concentrated blood vessels, so they can bleed from minor irritation. The stool color changes to black or bright red depending on where the tumor is located. If a tumor is the cause, symptoms such as pain, vomiting, diarrhea, constipation, loss of appetite, and weight loss may occur in addition to the bloody stool.

Constipation can also result in bloody stool, as the difficulty in passing stool can cause trauma to the anus, leaving blood on the surface of the stool.

Parasitic influences

Parasites in the digestive tract can cause bloody stool. These include Tritrichomonas, Giardia, hookworms, and Toxoplasma. Hookworms can cause black stool because they bite into the small intestine.

Cases caused by stress or sudden environmental changes

Environmental changes, such as moving, construction in the neighborhood, or the arrival of a new family member, can be a major source of stress for cats. Stress can disrupt the gastrointestinal tract, potentially leading to bloody stool. Ulcerative colitis can also be triggered by stress, resulting in bright red blood in the stool.

How to respond to bloody stool and home care

Observation in case of temporary bloody stool

Since most cases of bloody stool are not something to be left unaddressed, you should visit a veterinary clinic as soon as possible rather than waiting.

If the stool is hard and pellet-like, or if the cat seems to be straining during defecation, it may be constipated. Ensure they can drink plenty of water and use wet food to increase their dietary water intake. However, since tumors can also cause difficulty in defecation, you should visit a veterinary clinic immediately if there is no improvement.

If bloody stool appears after changing food, it might be an allergic reaction. If returning to the previous food improves the situation, it may be fine to observe.

Bloody stool caused by stress may improve if you provide the cat with a place to hide and live in a secure environment.

In any case, it is important to visit a veterinary clinic as soon as possible rather than waiting. When visiting the clinic, try to bring a stool sample with you.

Importance of dietary improvement and hydration

If bloody stool is caused by constipation or food allergies, home care becomes crucial. Constipation is a state where there is little moisture in the stool; cats that do not drink much water or are slightly dehydrated due to chronic kidney disease or diabetes may develop constipation.

To increase hydration, you need measures tailored to your cat's preferences, such as setting up water stations in several locations or trying ceramic or glass water containers. Since dry food is low in moisture, adding wet food, soaking the dry food, or mixing wet food broth into their drinking water can help them consume more fluids.

In the case of food allergies, the cat reacts to proteins in the food, causing inflammation. Therefore, discontinue the suspected food and switch to a therapeutic diet suitable for allergies. If it is an allergy, it is necessary to switch to a therapeutic diet until directed by a veterinarian.

Veterinary diagnosis and treatment flow

Examinations for bloody stool

When a cat with bloody stool is brought to the clinic, the veterinarian will first ask about the symptoms, what the cat eats, and its parasite prevention status. Then, they will palpate the cat to check its body condition, abdominal status, lymph node swelling, and inspect the inside of the mouth. If a stool sample was brought, they will examine the stool's condition and perform a microscopic analysis. In some cases, a rapid test kit may be used to check for specific viruses or parasites.

Depending on the cat's age and condition, a blood test may be performed. If further diagnostic testing is judged necessary, X-rays and ultrasound examinations will be conducted. Additionally, if there is a possibility of abnormalities near the anus, a rectal examination may be performed.

Treatment options for gastrointestinal abnormalities

Treatments vary depending on the disease: food allergies are treated with therapeutic diets, parasites require deworming, and enteritis caused by immune disorders is primarily treated by suppressing the immune system. If stress is considered the main cause, using supplements to alleviate stress and creating a secure environment is key. For bloody stool caused by tumors, surgery, chemotherapy, or radiation therapy are options.

When blood attaches to stool due to constipation, it is often due to underlying diseases like chronic kidney disease. While treating that, environmental improvements for hydration and dietary therapy are implemented.

Handling long-term symptoms and treatment planning

Bloody stool can occur due to transient enteritis, which usually improves in a few days. However, enteritis due to immune disorders, food allergies, and tumors require long-term treatment and often involve cycles of improvement and worsening.

Once the cause is identified, treatment starts with a sufficient dose of medication to control symptoms, and the dosage is reduced as improvement occurs. It is difficult to stop medication entirely, so adjustments are made based on how symptoms manifest. In the case of chemotherapy, treatment plans are developed based on protocols and blood data, and drugs are changed in the event of recurrence.

Daily management and health checks to prevent bloody stool

Balanced diet and regular deworming

If bloody stool is linked to constipation, diet, or parasites, it can be improved through reviewing the diet or regular deworming. If the cat doesn't drink much water or has kidney disease, use wet food effectively to ensure hydration.

Environment building to reduce stress

Stress can trigger enteritis, resulting in bloody stool. Eliminating stress can lead to improvement. To reduce stress, provide places where the cat feels secure and can hide. Lack of exercise can also be a source of stress. Installing a cat tower to allow exercise or increasing playtime with you is also important.

Aim for early detection with regular health checkups

Health checkups play an important role in the early detection of diseases. Stool examinations are sometimes included in health checkups. However, because stool tests during checkups primarily screen for parasites and bacteria, it is difficult to identify all diseases through a stool test alone.

Many owners are unaware that their cat may have constipation, loose stools, or bloody stools. Therefore, it is important to have regular checkups to understand the cat's current condition.

Summary

Bloody stool in cats can be life-threatening if left unobserved. If the stool color looks different than usual, visit a veterinary clinic early. Also, strive for proper diet management and a low-stress lifestyle.