Blood Diarrhea in Cats

Blood diarrhea in cats is not a disease itself, but rather a symptom of some other condition. When a cat is experiencing diarrhea, it's best to first determine whether the case is mild or severe. Bloody diarrhea would likely indicate a more severe condition. Other important information necessary to reach diagnosis would include how long the diarrhea has been present, whether or not the cat has lost weight, presence of any blood, mucus or other matter, and if the source of diarrhea is the small or large intestine. Small intestine problems will usually produce dark brown blood, or melana. Bright red or rusty colored flecks or spots usually come from the large intestine. This is called hematochezia and indicates problems in the lower tract, including the rectum or anus. Large amounts of bright red blood in diarrhea may indicate an entirely separate problem.

Concerns about Blood Diarrhea

While many cases of blood diarrhea in cats will indicate a serious problem, there are a few instances where it may be a temporary condition and rapidly clear itself. Stress may be released through the intestines, causing bloody stool, vomiting and loss of appetite. If some kind of foreign matter has been eaten or ingested, it may be causing problems in the digestive tract, or in the anus. This could cause blood to mix with stool or diarrhea. Generally, if blood is present and persists, if bright red blood appears in the diarrhea more than once or in quantities larger than a speck, if the cat seems to be constipated but is passing diarrhea, or if there is a significant increase in the frequency of bowel movements, these could be causes for concern.

Possible Causes of Blood Diarrhea in Cats

Many diseases, conditions, infections or situations can lead to blood diarrhea in cats. Some of the possible causes include:

  • Parasites
  • Bacteria
  • Food allergy or intolerance
  • Ingestion of foreign or toxic substances
  • Coccidia
  • Impacted anal glands
  • Irritation of the stomach or bowels
  • Polyps
  • Lower bowel cancer
  • Intestinal virus
  • Colitis
  • Damage or trauma to the anus or lower bowels
  • Blood clot disorders
  • Bowel problems

Testing and Treatment

Testing and treatment for blood diarrhea in cats will be largely determined by the factors discussed earlier. Examination of the rectal area may be necessary to discover any trauma, tumors or glandular problems. Blood tests may be run to get information on blood count and a profile of the chemicals present in the blood. Urinalysis may be performed and there are several tests that can be run on fecal matter. Colonoscopy, x-rays or ultrasounds may provide more in depth information regarding the condition of your cat's organs. Depending upon the results acquired, a change in diet may be the first recommendation. Antibiotics will help to treat any bacterial infections. Most parasites can be rapidly treated with prescription medication. More serious problems may require fluid therapy or other drug treatments.


When cats get diarrhea, you may be tempted to treat it yourself using over the counter medication. A cat's physiological makeup is very different from that of any other species. Many over the counter diarrhea remedies are extremely toxic to cats, and should not be given under any circumstances.