Blood in Cat Stool: Causes, When to Worry & What to Do Next

Let's be real. Cleaning the litter box isn't anyone's favorite chore, but it does make you a bit of a detective. You notice things. And one day, you see something that makes your heart drop: a streak of red, a dark spot, or something that just looks… wrong. Finding blood in your cat's stool is genuinely scary. Your mind races. Is this an emergency? Did they eat something bad? Is it something serious?

First, take a breath. You're not alone, and this doesn't automatically mean the worst. I remember the first time I saw it with my own cat, Mochi. I spent an hour frantically googling, getting more terrified with every click. The information was either too vague or doom-laden. That's why I wanted to write this—to give you the clear, step-by-step guide I wish I'd had.

Decoding the Clues: What the Blood Actually Looks Like

Not all blood in cat stool looks the same, and the appearance is your first major clue. Vets categorize it, and knowing the difference helps you describe it accurately.

So, your first note: Bright red or dark and tarry? That detail matters. Also, is it mixed throughout the poop, or just on the outside? Is the stool itself formed, or is it diarrhea with blood?

Honestly, I know it's gross, but maybe even snap a quick photo with your phone (just for the vet, I promise!). It's more reliable than trying to describe it from memory when you're anxious.

The "Why" Behind the Red Flag: Common and Serious Causes

Okay, so what's actually causing this? The list is long, which is why a vet's help is crucial. But understanding the possibilities helps you see why some situations are more urgent than others.

The More Common (Often Less Scary) Culprits

These are frequent reasons for seeing some blood in cat poop, especially the bright red kind (hematochezia).

• Dietary Indiscretion or Sudden Change: Cats have sensitive guts. A new food, a rich treat, or them sneaking a bite of something they shouldn't (like human food or a rogue bug) can cause inflammation and a bit of bleeding.
• Constipation and Straining: This is a big one. If the stool is hard and dry, passing it can strain the colon and rectum, causing small tears or irritation that bleed. You might see the blood on the surface of hard stools.
• Parasites: Worms like hookworms, roundworms, or whipworms can attach to the intestinal lining and cause irritation and bleeding. Even some single-celled parasites like Coccidia or Giardia can do this. The good news? These are often treatable.
• Food Allergies or Intolerances: An allergy to an ingredient (common ones are beef, dairy, fish) can cause chronic inflammation of the colon (colitis), leading to bloody, mucousy diarrhea.

The More Serious Causes That Need Prompt Attention

These require a vet's diagnosis and often more involved treatment. Don't panic, but do take them seriously.

• Inflammatory Bowel Disease (IBD): This is a chronic condition where the cat's own immune cells invade the intestinal wall, causing persistent inflammation, vomiting, diarrhea, and weight loss. Blood in the cat's stool can be a symptom.
• Infections: Bacterial infections (like Salmonella, Clostridium) or severe viral infections can damage the gut lining.
• Foreign Bodies or Trauma: If a cat swallows something sharp (a bone fragment, a needle) it can physically tear the intestines. Trauma from a fall or accident could also cause internal bleeding.
• Poisoning/Toxins: Ingesting certain toxins (like rat poison, which is an anticoagulant) can cause internal bleeding, which may show up as blood in stool or vomit. This is an absolute emergency.
• Anal Gland Issues: Impacted or infected anal glands can rupture or become abscessed, leading to blood in the stool or around the anus.
• Polyps or Tumors: Growths in the colon or rectum can bleed. This is more common in older cats. While the word "tumor" is terrifying, not all are cancerous, but all need evaluation.
• Coagulation Disorders: Problems with blood clotting (from liver disease, certain poisons, or genetic conditions) can lead to bleeding anywhere, including the gut.

Your Action Plan: From Litter Box to Vet Clinic

Alright, you've assessed the scene. Here's what to do, step by step.

Step 1: The Home Triage (Don't Skip This)

Before you call, gather intel. Your vet will ask these questions:

1. Cat's Overall Behavior: Is she acting normal? Playing, eating, drinking? Or hiding, lethargic, refusing food?
2. Stool Details: Color of blood (bright red/dark), consistency (hard/diarrhea), frequency. Any mucus?
3. Recent Changes: New food, treats, plants, access to human medication or cleaning products? Any chance they got into something?
4. Other Symptoms: Vomiting? Straining in the litter box? Weight loss? Increased thirst?

Step 2: The Vet Visit & What to Expect

You call, describe the symptoms, and get an appointment. Here's what the vet will likely do, so you're not in the dark.

In more persistent or severe cases, they might recommend:
- PCR Fecal Test: A more sensitive test for specific bacteria/parasites.
- Endoscopy/Colonoscopy: A camera scope to look directly at the intestinal lining and take biopsies. This is often the gold standard for diagnosing IBD or cancer.

I know this list looks intense. Not every cat needs every test. A good vet will start with the basics (fecal, blood work) and go from there based on your cat's specific story.

Treatment: It Totally Depends on the "Why"

There's no one pill for "blood in cat stool." Treatment is 100% aimed at the underlying cause.

• For Parasites: Deworming medication. Simple.
• For Bacterial Infections: A course of antibiotics.
• For Dietary Issues/Allergies: A strict prescription or limited-ingredient diet for 8-12 weeks. No cheating!
• For Constipation: Increasing fiber, hydration (wet food, water fountains), or stool softeners.
• For IBD: Often managed with a combination of a hypoallergenic diet and medication to suppress inflammation (like steroids).
• For Foreign Bodies: Surgery to remove the object.
• For Tumors: Surgery, possibly followed by biopsy to determine if it's cancerous and what further care is needed.

The treatment plan can feel overwhelming. Ask questions. "What are we treating?" "What's the goal of this medication?" "What are the side effects to watch for?" A good vet will welcome this.

Can You Prevent Blood in Cat Stool?

You can't prevent everything, but you can stack the odds in your cat's favor.

Questions I Had (And You Probably Do Too)

Q: My cat has blood in his stool but is acting completely fine. Should I still worry?

A: Yes, you should still call the vet. While it's a better sign that he's acting normal, it's still a signal that something is irritating his GI tract. It could be the early stage of something, or a mild issue that could worsen if ignored. Don't wait for him to feel bad.

Q: Could it be from dry food?

A: Not directly. But a diet that's too low in moisture can contribute to chronic constipation, which then leads to straining and hematochezia. If your cat eats only kibble, make sure they're drinking plenty of water, or consider adding wet food.

Q: How long after treatment should the blood go away?

A: It depends on the cause. For a simple parasite, it might clear in a few days after deworming. For colitis from a food allergy, it might take several weeks on the new diet to see full resolution. Your vet should give you a timeline.

Q: Is a little mucus with the blood normal?

A: Mucus is produced by the colon when it's inflamed. So, while it's a common finding (often called "colitis"), it's not "normal." It points even more strongly to inflammation in the lower bowel.

Q: My online research says it could be cancer. How likely is that?

A: Let's be real, this is the fear that haunts every pet owner in this situation. While it's a possibility, especially in older cats, it's not the most common cause. Far more often, it's parasites, food issues, or IBD. Let the diagnostic process rule out the more common things first before spiraling. Dr. Jane Brunt, a veterinarian, has written extensively on common vs. rare feline diagnoses for the American Association of Feline Practitioners (AAFP), which can provide balanced perspective.

Look, finding blood where it shouldn't be is alarming. But armed with the right information, you can move from panic to purposeful action. You become your cat's best advocate. Observe carefully, communicate clearly with your vet, and follow through with the diagnostic and treatment plan.

The goal isn't just to make the blood in the stool go away—it's to find and address the root cause so your cat gets back to feeling (and using the litter box) like their normal, healthy self.