When there is blood in a cat’s feces, it may either be bright red or very dark in colour, causing the excrement to look black. Blood in the stool has many different possible causes.
Causes of Blood in a Cat’s Stool
Blood in the stool may signify minor or serious problems, so it’s important to consult a veterinarian right away if you see it. In young cats, the most common cause of bloody stool is parasites, whereas in older pets, it’s more likely to signify a serious illness, such as cancer. The following are potential causes of bloody stool:
- Cancer of the intestines or stomach
- Coagulopathy (also known as bleeding disorder or clotting disorder)
- Constipation
- Idiopathic megacolon
- Infection
- Inflammation/abscess of the anal sack
- Inflammatory bowel disease (IBD)/colitis
- Ingestion of blood
- Ingestion of heavy metals (very rare)
- Ingestion of a sharp object (i.e., a bone)
- Injury
- Intestinal obstruction
- Intussusception of the bowel (one section “telescopes” into another)
- Irritable bowel syndrome (IBS)
- Ischemia (lack of gastrointestinal blood supply)
- Kidney or liver disease
- Parasite infestation
- Perineal hernia
- Polyps in the rectum or colon
- Post-surgical bleeding
- Prostate cancer
- Reactions to certain medications
- Reactions to eating inappropriate or toxic substances
- Ulcers
- Various gastrointestinal diseases
Additional Symptoms
Symptoms that may accompany blood in the stool depending on the underlying cause include:
- Appetite loss
- Bruising or bleeding on the body
- Diarrhea
- Increased number of bowel movements per day
- Increased thirst and urination
- Lethargy
- Pale gums
- Straining to defecate
- Vomiting
- Weight loss
In some cases, there are no additional symptoms.
Treatments
Treatments for bloody stool depend on the underlying cause, and may include:
- Antacids
- Antibiotics
- Anti-inflammatory medication
- Balloon dilation to widen the intestinal canal
- Blood transfusions (if anemia develops)
- Corticosteroids
- Deworming medication
- Dietary changes
- Fluid therapy
- Laxatives
- Medications that protect the gastrointestinal system and/or bind harmful substances
- Motility modifying drugs (which change the speed of food movement through the intestines)
- Surgery
- Vitamin K therapy (in the case of coagulopathies)
If you see blood in a cat’s stool, consult a veterinarian right away to rule out serious causes and obtain appropriate treatment. Bringing a stool sample along with your cat can help the veterinarian make a diagnosis more quickly and easily. Place the sample in a clean plastic bag or container, and be sure to wash your hands thoroughly with soap afterward, as some illnesses can be transmitted from pets to people.
For more information on cat symptoms, medical conditions, and treatments, visit the Cat Health and Safety page. For a full list of cat articles, see the main Cats page.
This article is provided for informational purposes only and is not intended as a substitute for veterinary consultation and care.
References:
- PetMD. (n.d.). “Difficult Defecation and Blood in Stool in Cats.” PetMD.com.
- Spielman, B., Dr. (2011). “Hematochezia (Blood in Stool) in Cats.” PetPlace.com.
- Spielman, B., Dr. (2011). “Melena (Blood in Stool) in Cats.” PetPlace.com.