Pet Health
· Updated March 03, 2026· 4 min read

Why Is My Cat Leaking Brown Fluid?

✓ Vet-Reviewed Content
Dr. James Bascharon
Written by Dr. James Bascharon, DVMVeterinarian | Founder & CEO
Last medically reviewed: March 03, 2026
Meet our Vet Advisory Board →

- A cat leaking brown fluid from the hind end may be caused by diarrhea, gastrointestinal issues, or anal gland problems — each requires a different approach to treatment
- Diarrhea from a stomach bug or food irritation can cause brown fluid leakage, and if symptoms persist past 24 hours it is important to consult a veterinarian because diarrhea can lead to dehydration
- Gastrointestinal issues such as colitis (frequent and painful passing of feces) and exocrine pancreatic insufficiency (large amounts of soft feces) are chronic conditions that can cause brown discharge and require veterinary attention
- Anal gland problems are a common cause of brown fluid in cats — the anal glands are two small pouches on either side of the anus that normally secrete a small amount of thin, yellow fluid during bowel movements
- Diseased or infected anal glands produce a thicker, brown discharge that may leak unpredictably, often accompanied by repeated licking of the anal area and visible inflammation or swelling
- If your cat has anal gland problems, a veterinarian may need to manually express the glands, and preventive measures including dietary supplementation can help support healthy anal gland function

If your cat is leaking brown fluid from their hind end, it could indicate an underlying health issue that needs attention. Understanding the cause is the first step in addressing the problem and supporting your cat's health.

Why Does My Cat Have a Leaky Bum?

There are several reasons why your cat may be leaking brown fluid. The most common causes are diarrhea, gastrointestinal issues, and anal gland problems.

Diarrhea

Your cat may be experiencing diarrhea due to a stomach bug or food irritation. Cats are typically capable of controlling their bowels, so if your cat cannot make it to the litter box in time, the issue may be severe. Diarrhea can lead to dehydration, so consult your veterinarian if symptoms persist past 24 hours.

Gastrointestinal Issues

Cats can experience a range of gastrointestinal (GI) conditions, many of which can cause diarrhea and brown discharge. Common GI issues include colitis, which involves the frequent and painful passing of feces, and exocrine pancreatic insufficiency, which is characterized by large amounts of soft feces due to inadequate digestive enzyme production. These are chronic conditions that require veterinary attention if symptoms persist.

Anal Gland Problems

Cats have anal glands, also known as anal sacs, which are two small pouches located on either side of the anus. These glands normally secrete a small amount of fluid when your cat passes a bowel movement. However, the anal glands can become irritated or infected, leading to brown discharge from the anus.

Healthy anal sacs typically produce thin, yellow fluid during a bowel movement. Diseased or infected anal sacs produce a thicker, brown discharge that may leak unpredictably. Other signs of anal gland problems include repeated licking of the anal area and visible inflammation or swelling around the glands.

If you suspect your cat is experiencing anal gland problems, consult your veterinarian, as the glands may need to be manually expressed. Preventive measures can also help reduce the likelihood of anal gland issues.

Supporting Your Cat's Digestive and Anal Gland Health

A fiber-rich diet helps promote firm stools that apply natural pressure to the anal glands during bowel movements, supporting regular expression. Glandex Probiotic & Prebiotic Powder for Cats provides fiber, probiotics, and digestive enzymes to support healthy digestion and normal anal gland function. For cats with existing anal gland concerns, Glandex Feline Anal Gland Supplement is specifically formulated to promote healthy anal gland expression.

If your cat is leaking brown fluid, it is important to identify the underlying cause and consult your veterinarian. Early attention can help resolve the issue and prevent more serious complications.

🩺
DR. JAMES BASCHARON SAYS
"Healthy anal sacs will typically produce thin, yellow fluids concurrent with a bowel movement. Diseased and infected anal sacs will produce a thicker, brown discharge that may leak unpredictably."
— Dr. James Bascharon, DVM , General Practice
Breeds commonly affected
Most at risk

Frequently Asked Questions

Why is my cat leaking brown fluid?

A cat leaking brown fluid from the hind end may be experiencing diarrhea, gastrointestinal issues, or anal gland problems. Diarrhea from a stomach bug or food irritation is one common cause. Gastrointestinal conditions like colitis or exocrine pancreatic insufficiency can also cause brown discharge. Anal gland problems, where the glands become irritated or infected, often produce a thicker brown fluid that leaks unpredictably.

What do healthy cat anal glands look like versus diseased ones?

Healthy anal glands typically produce thin, yellow fluid that is secreted naturally during bowel movements. Diseased or infected anal glands produce a thicker, brown discharge that may leak unpredictably outside of normal bowel movements. Other signs of anal gland problems include repeated licking of the anal area and visible inflammation or swelling around the glands.

When should I take my cat to the vet for brown fluid leakage?

Consult your veterinarian if diarrhea persists past 24 hours, as it can lead to dehydration. For suspected gastrointestinal issues like colitis or exocrine pancreatic insufficiency, veterinary attention is needed since these are chronic conditions. If you believe your cat has anal gland problems, a veterinarian may need to manually express the glands and assess for infection.

Can I prevent anal gland problems in my cat?

Yes. Preventive measures include feeding a balanced, fiber-rich diet to promote firm stools that help the anal glands express naturally during bowel movements. Dietary supplements formulated for anal gland health can also support normal gland function. Regular veterinary check-ups help catch issues early before they become more serious.

What is colitis in cats?

Colitis is inflammation of the colon that causes frequent and painful passing of feces. It is a gastrointestinal condition that can lead to diarrhea and brown discharge. Colitis in cats can be acute or chronic, and persistent symptoms should be evaluated by a veterinarian to determine the underlying cause and appropriate treatment.

What is exocrine pancreatic insufficiency in cats?

Exocrine pancreatic insufficiency (EPI) is a condition where the pancreas does not produce enough digestive enzymes. It is characterized by large amounts of soft feces because nutrients are not being properly broken down and absorbed. EPI is a chronic condition that requires ongoing veterinary management.

Sources

- Anal Sac Disease in Cats — VCA Animal Hospitals
- Feline Digestive Disorders — Hill's Pet Nutrition
- Cat Anal Gland Information — Glandex (glandex.com)

📋
Veterinary Disclaimer

Vetnique Labs was founded by Dr. James Bascharon, DVM, and all content is reviewed by our Vet Advisory Board. This information is not a substitute for professional veterinary advice. Always consult your veterinarian.

Dr. James Bascharon
About the Author

Dr. James Bascharon, DVM

Veterinarian | Founder & CEO

Dr. James Bascharon is a veterinarian, entrepreneur, and the visionary founder of Vetnique. He launched Vetnique in 2012 after formulating Glandex® in his own kitchen to address anal gland health in pets.

Search