What’s Causing the Blood in My Cat’s Stool?

Our veterinary expert, Arnold Plotnick, DVM, says that colitis is the most likely culprit behind bloody cat stool.

Q: My cat Roofis is about 8 months old. I noticed that sometimes when he defecates there is blood in his stool. I recently treated him for worms. Could the worms cause my cat to have blood in his stool, or could it be something more serious?

A: When bleeding occurs from the stomach or the small intestine, the blood gets digested, and this turns the stool black, like tar. When bleeding occurs in the large intestine, digestion has already occurred, and the blood has its familiar red appearance. The fact that you see red blood suggests that he has colitis, which is an inflammation of his large intestine.  

In a young cat, intestinal parasites are certainly a possibility, and a fecal sample should be evaluated by your veterinarian. A sudden change in diet is another common cause for colitis, so be consistent in the food you offer to your cat. If you ever do alter his diet, do it gradually, throughout the course of several days to minimize the chances of colitis.
Stress is another common cause of colitis. Any sudden change in his environment — a new cat in the household, a new person, a drastic change in the owner’s schedule — can sometimes trigger colitis. In any event, an 8-month-old kitten is pretty unlikely to have a serious problem. In most cases of kitten colitis, a parasite or a dietary cause is usually the culprit.  

Arnold Plotnick, DVM

Article Categories:
Behavior and Training · Cats


  • I have a question.I have a cat that’s probably between 4 to 6 Mta. She was an wild cat I found in the woods. When i first got her she was to small for hard food, the wet food was to much for her stomach and gave her terrible dirreaha. I just gave her water and milk and slowly introduced the dry food. Anyways long story short since taken her in she has gain weight and is doing well for the most part. Now my question is while cleaning her litter box I noticed some looks like slimey blood in her poop. There are no other signs of being sick and I really can’t afford to go to tree vet . Can someone please tell me wat can cause this

    Nicole December 28, 2016 7:12 pm Reply

Leave a Comment

Your email address will not be published. Required fields are marked *